Note: Descriptions are shown in the official language in which they were submitted.
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Rotary Piston Type Actuator With Hydraulic Supply
CLAIM OF PRIORITY
[0001] This application claims priority to U.S. Patent Application No.
14/258,434 filed on April 22, 2014, which is a continuation-in-part of a U.S.
Patent Application No. 13/778,561, filed February 27, 2013 and entitled
"ROTARY PISTON TYPE ACTUATOR", U.S. Patent Application Serial No.
13/831,220, filed March 14, 2013 and entitled "ROTARY PISTON TYPE
ACTUATOR WITH A CENTRAL ACTUATION ASSEMBLY", U.S. Patent
Application Serial No. 13/921,904, filed June 19, 2013 and entitled "ROTARY
PISTON TYPE ACTUATOR WITH A CENTRAL ACTUATION ASSEMBLY",
U.S. Patent Application Serial No. 14/170,434, filed January 31, 2014 and
entitled "ROTARY PISTON TYPE ACTUATOR WITH PIN RETENTION
FEATURES", and U.S. Patent Application Serial No. 14/170,461, filed January
31, 2014 and entitled "ROTARY PISTON TYPE ACTUATOR WITH MODULAR
HOUSING", the disclosures of which are incorporated by reference in their
entirety.
TECHNICAL FIELD
[0002] This invention relates to an actuator device and more particularly
to
a rotary piston type actuator device wherein the pistons of the rotor are
moved
by fluid under pressure and wherein the actuator device includes a central
actuation assembly adapted for attachment to and external mounting feature
on a member to be actuated.
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BACKGROUND
[0003] Rotary hydraulic actuators of various forms are currently used in
industrial mechanical power conversion applications. This industrial usage is
commonly for applications where continuous inertial loading is desired without
the need for load holding for long durations, e.g. hours, without the use of
an
external fluid power supply. Aircraft flight control applications generally
implement loaded positional holding, for example, in a failure mitigation
mode,
using the blocked fluid column to hold position.
[0004] In certain applications, such as primary flight controls used for
io aircraft operation, positional accuracy in load holding by rotary
actuators is
desired. Positional accuracy can be improved by minimizing internal leakage
characteristics inherent to the design of rotary actuators. However, it can be
difficult to provide leak-free performance in typical rotary hydraulic
actuators,
e.g., rotary "vane" or rotary "piston" type configurations.
SUMMARY
[0005] In general, this document relates to rotary piston-type actuators.
[0006] In a first aspect, a rotary actuator system includes a first
housing
defining a first arcuate chamber comprising a first cavity, a first fluid port
in
fluid communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and comprising a rotary output shaft
and a first rotor arm extending radially outward from the rotary output shaft,
an
arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end, wherein a first
seal, the first cavity, and the first piston define a first pressure chamber,
and a
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first portion of the first piston contacts the first rotor arm, a first fluid
line
coupled to the first fluid port, a high pressure fluid line, a low pressure
fluid
line, a central pressure source coupled to the high pressure fluid line, and a
servo valve positioned between the central pressure source and the rotary
actuator and being controllable to selectively connect the first fluid line to
the
high pressure fluid line and the low pressure fluid line to control movement
of
the rotary actuator.
[0007] Various embodiments can include some, all, or none of the
following
features. The first housing can further define a second arcuate chamber
io comprising a second cavity, and a second fluid port in fluid
communication with
the second cavity, wherein the rotor assembly further includes a second rotor
arm, wherein the rotary actuator further including an arcuate-shaped second
piston disposed in said first housing for reciprocal movement in the second
arcuate chamber, wherein a second seal, the second cavity, and the second
piston define a second pressure chamber, and a first portion of the second
piston contacts the second rotor arm, and wherein the rotary actuator system
further includes a second fluid line coupled to the second fluid port, and the
servo valve is further controllable to selectively connect the second fluid
line to
the high pressure fluid line and the low pressure fluid line to control
movement
of the rotary actuator. The rotary actuator system can include a controller
coupled to control the servo valve. The rotary actuator system can include a
position sensor configured to provide a position feedback signal, wherein the
controller is further configured to receive a position feedback signal from
the
position sensor and control the servo valve based on the position feedback
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signal. The position sensor can be coupled to the rotary output shaft, wherein
the controller, the servo, and the position sensor form a feedback loop. The
position sensor can be a position limit sensor, and the controller is further
configured to receive a position limit signal from the position sensor and
control the servo valve based on the position limit signal. The first seal can
be
disposed about an interior surface of the open end. The first seal can be
disposed about the periphery of the first piston. The first housing can be
formed as a one-piece housing. The first seal can be a one-piece seal. The
first rotor arm can be coupled to a flight control surface of an aircraft. The
first
io rotor arm can be coupled to a primary flight control surface of an
aircraft. The
central pressure source can be a central hydraulic system of an aircraft. The
rotary actuator system can include a central actuation assembly including a
central mounting point formed in an external surface of the rotary output
shaft,
said central mounting point proximal to the longitudinal midpoint of the
rotary
output shaft, and an actuation arm removably attached at a proximal end to the
central mounting point, said actuation arm adapted at a distal end for
attachment to an external mounting feature of a member to be actuated.
[0008] In a second aspect, a method of rotary actuation includes
providing
a rotary actuator including a first housing defining a first arcuate chamber
comprising a first cavity, a first fluid port in fluid communication with the
first
cavity, and an open end, a rotor assembly rotatably journaled in said first
housing and comprising a rotary output shaft and a first rotor arm extending
radially outward from the rotary output shaft; and an arcuate-shaped first
piston disposed in said first housing for reciprocal movement in the first
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arcuate chamber through the open end, wherein a first seal, the first cavity,
and the first piston define a first pressure chamber, and a first portion of
the
first piston contacts the first rotor arm, a first fluid line coupled to the
first fluid
port, a high pressure fluid line, and a low pressure fluid line, providing a
central
pressure source coupled to the high pressure fluid line, providing a servo
valve
positioned between the central pressure source and the rotary actuator,
controlling the servo valve to selectively connect the first fluid line to the
high
pressure fluid line and the low pressure fluid line to apply pressurized fluid
to
the first pressure chamber, and urging the first piston partially outward from
the
io first pressure chamber to urge rotation of the rotary output shaft in a
first
direction.
[0009] Various implementations can include some, all, or none of the
following features. The first housing can further defines a second arcuate
chamber having a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly includes a
second rotor arm, wherein the rotary actuator includes an arcuate-shaped
second piston disposed in said first housing for reciprocal movement in the
second arcuate chamber, and a second seal, the second cavity, and the
second piston define a second pressure chamber, and a first portion of the
second piston contacts the second rotor arm, wherein a second fluid line is
coupled to the second fluid port, and the servo valve is further controllable
to
selectively connect the second fluid line to the high pressure fluid line and
the
low pressure fluid line to control movement of the rotary actuator, and the
method further includes controlling the servo valve to selectively connect the
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second fluid line to the high pressure fluid line and the low pressure fluid
line to
apply pressurized fluid to the second pressure chamber, and urging the
second piston partially outward from the second pressure chamber. The
method can include providing a controller coupled to control the servo valve,
and wherein controlling the servo valve further comprises controlling, by the
controller, the servo valve to selectively connect the first fluid line to the
high
pressure fluid line and the low pressure fluid line to apply pressurized fluid
to
the first pressure chamber. The method can also include providing a position
sensor configured to provide a position feedback signal indicative of a
position
io of the rotary actuator, receiving, by the controller, a position
feedback signal
from the position sensor to control the servo valve, and controlling, by the
controller, the servo valve to selectively connect the first fluid line to the
high
pressure fluid line and the low pressure fluid line to apply pressurized fluid
to
the first pressure chamber based on the position feedback signal. The position
sensor can be coupled to the rotary output shaft, and the position feedback
signal is a rotary position feedback signal. The position sensor can be a
position limit sensor, and the position feedback signal is a position limit
signal.
Urging the first piston partially outward from the first pressure chamber to
urge
rotation of the rotary output shaft in a first direction can include urging
rotation
of the rotary output shaft to control at least one of the group consisting of
rotary output shaft speed, rotary output shaft position, rotary output shaft
torque, and rotary output shaft acceleration. The method can also include
providing a central actuation assembly including a central mounting point
formed in an external surface of the rotary output shaft, said central
mounting
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point proximal to the longitudinal midpoint of the rotary output shaft,
providing
an actuation arm removably attached at a proximal end to the central mounting
point, said actuation arm adapted at a distal end for attachment to an
external
mounting feature of a member to be actuated, urging rotation of the actuation
arm, and urging motion of the member to be actuated.
[0010] In a third aspect, a rotary actuator system includes a first
housing
defining a first arcuate chamber comprising a first cavity, a first fluid port
in
fluid communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and comprising a rotary output shaft
io and a first rotor arm extending radially outward from the rotary output
shaft, an
arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end, wherein a first
seal, the first cavity, and the first piston define a first pressure chamber,
and a
first portion of the first piston contacts the first rotor arm, a first fluid
line
coupled to the first fluid port, a fluid reservoir, and a fluid pump coupled
to the
fluid reservoir, the fluid pump being controllable to selectively provide high
pressure to the first fluid line to control movement of the rotary actuator,
wherein the fluid pump is not connected to a central hydraulic system.
[0011] Various embodiments can include some, all, or none of the
following
features. The first housing can further define a second arcuate chamber
comprising a second cavity, and a second fluid port in fluid communication
with
the second cavity, wherein the rotor assembly further includes a second rotor
arm, wherein the rotary actuator further includes an arcuate-shaped second
piston disposed in said first housing for reciprocal movement in the second
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arcuate chamber, wherein a second seal, the second cavity, and the second
piston define a second pressure chamber, and a first portion of the second
piston contacts the second rotor arm, and wherein the rotary actuator further
includes a second fluid line coupled to the second fluid port, and the fluid
pump
is further controllable to selectively provide high pressure to the second
fluid
line to control movement of only the rotary actuator. The rotary actuator
system can include a controller coupled to control the fluid pump. The rotary
actuator system can include a position sensor configured to provide a position
feedback signal, wherein the controller is further configured to receive a
io position feedback signal from the position sensor and control the fluid
pump
based on the position feedback signal. The position sensor can be coupled to
the rotary output shaft, wherein the controller, the fluid pump, and the
position
sensor form a feedback loop. The position sensor can be a position limit
sensor and the controller can be further configured to receive a position
limit
signal from the position sensor and control the fluid pump based on the
position limit signal. The first seal can be disposed about an interior
surface of
the open end. The first seal can be disposed about the periphery of the first
piston. The first housing can be formed as a one-piece housing. The first seal
can be a one-piece seal. The rotary actuator system can also include a central
actuation assembly including a central mounting point formed in an external
surface of the rotary output shaft, said central mounting point proximal to
the
longitudinal midpoint of the rotary output shaft, and an actuation arm
removably attached at a proximal end to the central mounting point, said
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actuation arm adapted at a distal end for attachment to an external mounting
feature of a member to be actuated.
[0012] In a fourth aspect, a method of rotary actuation includes
providing a
rotary actuator including a first housing defining a first arcuate chamber
comprising a first cavity, a first fluid port in fluid communication with the
first
cavity, and an open end, a rotor assembly rotatably journaled in said first
housing and comprising a rotary output shaft and a first rotor arm extending
radially outward from the rotary output shaft; and an arcuate-shaped first
piston disposed in said first housing for reciprocal movement in the first
arcuate chamber through the open end, wherein a first seal, the first cavity,
and the first piston define a first pressure chamber, and a first portion of
the
first piston contacts the first rotor arm, and a first fluid line coupled to
the first
fluid port, providing a fluid reservoir, providing a fluid pump coupled to
the
fluid reservoir, controlling the fluid pump to selectively provide high
pressure to
the first fluid line to apply pressurized fluid to the first pressure chamber,
and
urging the first piston partially outward from the first pressure chamber to
urge
rotation of the rotary output shaft in a first direction.
[0013] Various implementations can include some, all, or none of the
following features. The first housing can also define a second arcuate
chamber comprising a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly further
includes a second rotor arm, wherein the rotary actuator further includes an
arcuate-shaped second piston disposed in said first housing for reciprocal
movement in the second arcuate chamber, wherein a second seal, the second
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cavity, and the second piston define a second pressure chamber, and a first
portion of the second piston contacts the second rotor arm, wherein a second
fluid line is coupled to the second fluid port, and the method further
includes
controlling the fluid pump to selectively provide high pressure to the
second fluid line to apply pressurized fluid to the second pressure chamber,
and urging the second piston partially outward from the second pressure
chamber. The method can also include providing a controller coupled to
control the fluid pump, and wherein controlling the fluid pump can include
controlling, by the controller, the fluid pump to selectively apply
pressurized
fluid to the first pressure chamber. The method can include providing a
position sensor configured to provide a position feedback signal indicative of
a
position of the rotary actuator, receiving, by the controller, a position
feedback
signal from the position sensor to control the fluid pump, and controlling, by
the
controller, the fluid pump to selectively apply pressurized fluid to the first
pressure chamber based on the position feedback signal. The position sensor
can be coupled to the rotary output shaft, and the position feedback signal
can
be a rotary position feedback signal. The position sensor can be a position
limit sensor, and the position feedback signal can be a position limit signal.
Urging the first piston partially outward from the first pressure chamber to
urge
rotation of the rotary output shaft in a first direction can include urging
rotation
of the rotary output shaft to control at least one of the group consisting of
rotary output shaft speed, rotary output shaft position, rotary output shaft
torque, and rotary output shaft acceleration. The method can include providing
a central actuation assembly including a central mounting point formed in an
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external surface of the rotary output shaft, said central mounting point
proximal
to the longitudinal midpoint of the rotary output shaft, providing an
actuation
arm removably attached at a proximal end to the central mounting point, said
actuation arm adapted at a distal end for attachment to an external mounting
feature of a member to be actuated, urging rotation of the actuation arm, and
urging motion of the member to be actuated.
[0014] In a fifth aspect, a rotary actuator includes a first housing
defining a
first arcuate chamber comprising a first cavity, a first fluid port in fluid
communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and comprising a rotary output shaft
and a first rotor arm extending radially outward from the rotary output shaft,
an
arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end, wherein a first
seal, the first cavity, and the first piston define a first pressure chamber,
and a
first portion of the first piston contacts the first rotor arm, a first fluid
line
coupled to the first fluid port, a high pressure fluid line, a low pressure
fluid
line, a central pressure source coupled to the high pressure fluid line, a
servo
valve positioned between the central pressure source and the rotary actuator,
the servo being controllable to selectively connect the first fluid line to
the high
pressure fluid line and the low pressure fluid line to control movement of the
rotary actuator, a fluid reservoir, a fluid pump coupled to the fluid
reservoir,
the fluid pump being controllable to selectively provide high pressure to the
first fluid line to control movement of the rotary actuator, and a valve block
positioned between the rotary actuator, the servo valve, and the fluid pump,
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the valve block being controllable to selectively provide high pressure to the
first fluid line from the fluid pump and the servo valve.
[0015] Various embodiments can include some, all, or none of the
following
features. The first housing can also define a second arcuate chamber
comprising a second cavity, and a second fluid port in fluid communication
with
the second cavity, wherein the rotor assembly further includes a second rotor
arm, wherein the rotary actuator further includes an arcuate-shaped second
piston disposed in said first housing for reciprocal movement in the second
arcuate chamber, wherein a second seal, the second cavity, and the second
io piston define a second pressure chamber, and a first portion of the
second
piston contacts the second rotor arm, and wherein the rotary actuator system
further includes a second fluid line coupled to the second fluid port, and the
valve block is further controllable to selectively connect the second fluid
line to
the high pressure fluid line and the low pressure fluid line to control
movement
of the rotary actuator. The rotary actuator system can also include a
controller
coupled to control the valve block, the fluid pump, and the servo valve. The
rotary actuator system can include a position sensor configured to provide a
position feedback signal, wherein the controller is further configured to
receive
a position feedback signal from the position sensor and control the servo
valve
and the fluid pump based on the position feedback signal. The position sensor
can be coupled to the rotary output shaft, wherein the controller, the servo,
and
the position sensor form a first feedback loop, and the controller, the fluid
pump, and the position sensor form a second feedback loop. The position
sensor can be a position limit sensor and the controller can be further
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configured to receive a position limit signal from the position sensor and
control the servo valve and the fluid pump based on the position limit signal.
The first seal can be disposed about an interior surface of the open end. The
first seal can be disposed about the periphery of the first piston. The first
housing can be formed as a one-piece housing. The first seal can be a one-
piece seal. The first rotor arm can be coupled to a flight control surface of
an
aircraft. The first rotor arm can be coupled to a primary flight control
surface of
an aircraft. The central pressure source can be a central hydraulic system of
an aircraft. The rotary actuator system can also include a central actuation
io assembly including a central mounting point formed in an external
surface of
the rotary output shaft, said central mounting point proximal to the
longitudinal
midpoint of the rotary output shaft, and an actuation arm removably attached
at a proximal end to the central mounting point, said actuation arm adapted at
a distal end for attachment to an external mounting feature of a member to be
actuated.
[0016] In a sixth aspect, a method of rotary actuation includes providing
a
rotary actuator that includes a first housing defining a first arcuate chamber
comprising a first cavity, a first fluid port in fluid communication with the
first
cavity, and an open end, a rotor assembly rotatably journaled in said first
housing and comprising a rotary output shaft and a first rotor arm extending
radially outward from the rotary output shaft, an arcuate-shaped first
piston
disposed in said first housing for reciprocal movement in the first arcuate
chamber through the open end, wherein a first seal, the first cavity, and the
first piston define a first pressure chamber, and a first portion of the first
piston
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contacts the first rotor arm, a first fluid line coupled to the first fluid
port, a high
pressure fluid line, and a low pressure fluid line, providing a central
pressure
source coupled to the high pressure fluid line, providing a servo valve
positioned between the central pressure source and the rotary actuator, the
servo being controllable to selectively connect the first fluid line to the
high
pressure fluid line and the low pressure fluid line to control movement of the
rotary actuator, providing a fluid reservoir, providing a fluid pump coupled
to
the fluid reservoir, the fluid pump being controllable to selectively provide
high
pressure to the first fluid line to control movement of the rotary actuator,
io providing a valve block positioned between the rotary actuator, the
servo
valve, and the fluid pump, the valve block being controllable to selectively
provide high pressure to the first fluid line from the fluid pump and the
servo
valve, controlling the fluid pump, the valve block, and the servo valve to
selectively provide high pressure to the first fluid line to apply pressurized
fluid
to the first pressure chamber, and urging the first piston partially outward
from
the first pressure chamber to urge rotation of the rotary output shaft in a
first
direction.
[0017] Various implementations can include some, all, or none of the
following features. The first housing can further define a second arcuate
chamber having a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly further
includes a second rotor arm, wherein the rotary actuator further includes an
arcuate-shaped second piston disposed in said first housing for reciprocal
movement in the second arcuate chamber, wherein a second seal, the second
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cavity, and the second piston define a second pressure chamber, and a first
portion of the second piston contacts the second rotor arm, and wherein the
rotary actuator system further includes a second fluid line coupled to the
second fluid port, and the valve block is further controllable to selectively
connect the second fluid line to the high pressure fluid line and the low
pressure fluid line to control movement of the rotary actuator. The method can
include providing a controller, wherein controlling the servo valve includes
controlling, by the controller, the servo valve to selectively connect the
first
fluid line to the high pressure fluid line and the low pressure fluid line to
apply
io pressurized fluid to the first pressure chamber, wherein controlling the
fluid
pump comprises controlling, by the controller, the fluid pump to selectively
apply pressurized fluid to the first pressure chamber, and wherein controlling
the valve block includes controlling, by the controller, the valve block to
selectively connect the servo valve and the fluid pump to the first pressure
chamber. The method can include providing a position sensor configured to
provide a position feedback signal indicative of a position of the rotary
actuator, receiving, by the controller, a position feedback signal from the
position sensor, wherein the controller, the servo, and the position sensor
can
form a first feedback loop, and the controller, the fluid pump, and the
position
sensor can form a second feedback loop, and wherein controlling the servo
valve and the fluid pump to apply pressurized fluid to the first pressure
chamber based on the position feedback signal. The position sensor can be
coupled to the rotary output shaft, the position feedback signal can be a
rotary
position feedback signal, and the controller can be further configured to
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receive a rotary position feedback signal from the position sensor and control
the servo valve and the fluid pump based on the rotary position feedback
signal. The position sensor can be a position limit sensor, and the controller
can be further configured to receive a position limit signal from the position
sensor and control the servo valve and the fluid pump based on the position
limit signal. The first seal can be disposed about an interior surface of the
open end. The first seal can be disposed about the periphery of the first
piston. The first housing can be formed as a one-piece housing. The first seal
can be a one-piece seal. The first rotor arm can be coupled to a flight
control
surface of an aircraft. The first rotor arm can be coupled to a flight control
surface of an aircraft. The first rotor arm can be coupled to a primary flight
control surface of an aircraft. The central pressure source can include a
central hydraulic system of an aircraft. Urging the first piston partially
outward
from the first pressure chamber to urge rotation of the rotary output shaft in
a
first direction can further include urging rotation of the rotary output shaft
to
control at least one of the group consisting of rotary output shaft speed,
rotary
output shaft position, rotary output shaft torque, and rotary output shaft
acceleration. The method can include providing a central actuation assembly
including a central mounting point formed in an external surface of the rotary
output shaft, said central mounting point proximal to the longitudinal
midpoint
of the rotary output shaft, providing an actuation arm removably attached at a
proximal end to the central mounting point, said actuation arm adapted at a
distal end for attachment to an external mounting feature of a member to be
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actuated, urging rotation of the actuation arm, and urging motion of the
member to be actuated.
[0018] In a seventh aspect, a rotary actuator system includes a first
housing
defining a first arcuate chamber comprising a first cavity, a second cavity, a
first fluid port in fluid communication with the first cavity, a second fluid
port in
fluid communication with the second cavity, a first open end, and a second
open end, a rotor assembly rotatably journaled in said first housing and
comprising a rotary output shaft, a first rotor arm extending radially outward
from the rotary output shaft, and a second rotor arm extending radially
outward
io from the rotary output shaft, an arcuate-shaped first piston disposed in
said
first housing for reciprocal movement in the first arcuate chamber through the
first open end, wherein a first seal, the first cavity, and the first piston
define a
first pressure chamber, and a first portion of the first piston contacts the
first
rotor arm, an arcuate-shaped second piston disposed in said second housing
for reciprocal movement in the second arcuate chamber through the second
open end, wherein a second seal, the second cavity, and the second piston
define a second pressure chamber, and a second portion of the second piston
contacts the second rotor arm, a first fluid line coupled to the first fluid
port, a
high pressure fluid line, a low pressure fluid line, a central pressure source
coupled to the high pressure fluid line, a servo valve positioned between the
central pressure source and the rotary actuator, the servo being controllable
to
selectively connect the first fluid line to the high pressure fluid line and
the low
pressure fluid line to control movement of the rotary actuator, a second fluid
line coupled to the second fluid port, a fluid reservoir, an electric powered
fluid
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pump coupled to the fluid reservoir, the fluid pump being controllable to
selectively provide high pressure to the second fluid line to control movement
of the rotary actuator.
[0019] Various embodiments can include some, all, or none of the
following
features. The fluid pump may not be connected to a central hydraulic system.
The rotary actuator system can include a first controller coupled to control
the
servo valve and a second controller coupled to control the fluid pump. The
rotary actuator system can include a position sensor configured to provide a
position feedback signal, wherein the first controller is further configured
to
io receive a position feedback signal from the position sensor and control
the
servo valve based on the position feedback signal and the second controller is
further configured to receive the position feedback signal from the position
sensor and control the fluid pump based on the position feedback signal. The
position sensor can be coupled to the rotary output shaft, wherein the first
controller, the servo, and the position sensor comprise a first feedback loop
and the second controller, the fluid pump, and the position sensor comprise a
second feedback loop. The position sensor can be a position limit sensor, and
the first controller and the second controller can be further configured to
receive a position limit signal from the position sensor and control the servo
valve and the fluid pump based on the position limit signal. The first seal
can
be disposed about an interior surface of the open end. The first seal can be
disposed about the periphery of the first piston. The first housing can be
formed as a one-piece housing. The first seal can be a one-piece seal. The
first rotor arm can be coupled to a flight control surface of an aircraft. The
first
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rotor arm can be coupled to a primary flight control surface of an aircraft.
The
central pressure source can include a central hydraulic system of an aircraft.
The rotary actuator system can include a central actuation assembly including
a central mounting point formed in an external surface of the rotary output
shaft, said central mounting point proximal to the longitudinal midpoint of
the
rotary output shaft, and an actuation arm removably attached at a proximal
end to the central mounting point, said actuation arm adapted at a distal end
for attachment to an external mounting feature of a member to be actuated.
[0020] In an eighth aspect, a method of rotary actuation includes
providing
io a rotary actuator that includes a first housing defining a first arcuate
chamber
comprising a first cavity, a second cavity, a first fluid port in fluid
communication with the first cavity, a second fluid port in fluid
communication
with the second cavity, a first open end, and a second open end, a rotor
assembly rotatably journaled in said first housing and comprising a rotary
output shaft, a first rotor arm extending radially outward from the rotary
output
shaft, and a second rotor arm extending radially outward from the rotary
output
shaft, an arcuate-shaped first piston disposed in said first housing for
reciprocal movement in the first arcuate chamber through the first open end,
wherein a first seal, the first cavity, and the first piston define a first
pressure
chamber, and a first portion of the first piston contacts the first rotor arm,
an
arcuate-shaped second piston disposed in said second housing for reciprocal
movement in the second arcuate chamber through the second open end,
wherein a second seal, the second cavity, and the second piston define a
second pressure chamber, and a second portion of the second piston contacts
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the second rotor arm, a first fluid line coupled to the first fluid port, a
second
fluid line coupled to the second fluid port, a high pressure fluid line, and a
low
pressure fluid line, providing a central pressure source coupled to the high
pressure fluid line, providing a servo valve positioned between the central
pressure source and the rotary actuator, providing a fluid reservoir,
providing a
fluid pump coupled to the fluid reservoir, controlling the servo valve to
selectively provide high pressure to the first fluid line to apply pressurized
fluid
to the first pressure chamber, controlling the fluid pump to selectively
provide
high pressure to the second fluid line to apply pressurized fluid to the
second
io pressure chamber, and urging the second piston partially outward from
the
second pressure chamber to urge rotation of the rotary output shaft in a first
direction.
[0021] Various implementations can include some, all, or none of the
following features. The method of claim 86, wherein the fluid pump is not
connected to a central hydraulic system. The method can also include
providing a first controller coupled to control the servo valve, and providing
a
second controller coupled to control the fluid pump. The method can also
include providing a position sensor configured to provide a position feedback
signal indicative of a position of the rotary actuator, receiving, at the
first
controller and the second controller, position feedback signal from the
position
sensor, controlling, by first controller, the servo valve based on the
position
feedback signal, and controlling, by the second controller, the fluid pump
based on the position feedback signal. The position sensor can be coupled to
the rotary output shaft, wherein the first controller, the servo, and the
position
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sensor form a first feedback loop and the second controller, the fluid pump,
and the position sensor form a second feedback loop. The position sensor can
be a position limit sensor, and the first controller and the second controller
can
be further configured to receive a position limit signal from the position
sensor
and control the servo valve and the fluid pump based on the position limit
signal. The first seal can be disposed about an interior surface of the open
end. The first seal can be disposed about the periphery of the first piston.
The
first housing can be formed as a one-piece housing. The first seal can be a
one-piece seal. The first rotor arm can be coupled to a flight control surface
of
io an aircraft. The first rotor arm can be coupled to a primary flight
control
surface of an aircraft. The central pressure source can include a central
hydraulic system of an aircraft. Urging the first piston partially outward
from
the first pressure chamber to urge rotation of the rotary output shaft in a
first
direction can include urging rotation of the rotary output shaft to control at
least
one of the group consisting of rotary output shaft speed, rotary output shaft
position, rotary output shaft torque, and rotary output shaft acceleration.
The
method can also include providing a central actuation assembly including a
central mounting point formed in an external surface of the rotary output
shaft,
said central mounting point proximal to the longitudinal midpoint of the
rotary
output shaft, providing an actuation arm removably attached at a proximal end
to the central mounting point, said actuation arm adapted at a distal end for
attachment to an external mounting feature of a member to be actuated, urging
rotation of the actuation arm, and urging motion of the member to be actuated.
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[0022] The systems and techniques described herein may provide one or
more of the following advantages. First, a controller-based actuation system
can utilize the performance characteristics of a rotary piston actuator.
Second,
a rotary actuator can be operated using fluid supplied locally and/or from a
central fluid supply. Third, rotary actuator can be redundantly supplied with
pressurized fluid from one or more local and/or central fluid supplies.
[0023] The details of one or more implementations are set forth in the
accompanying drawings and the description below. Other features and
advantages will be apparent from the description and drawings, and from the
io claims.
DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a perspective view of an example rotary piston-type
actuator.
[0025] FIG. 2 is a perspective view of an example rotary piston assembly.
[0026] FIG. 3 is a perspective cross-sectional view of an example rotary
piston-type actuator.
[0027] FIG. 4 is a perspective view of another example rotary piston-type
actuator.
[0028] FIGs. 5 and 6 are cross-sectional views of an example rotary
piston-
type actuator.
[0029] FIG. 7 is a perspective view of another embodiment of a rotary
piston-type actuator.
[0030] FIG. 8 is a perspective view of another example of a rotary piston-
type actuator.
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[0031] FIGs. 9 and 10 show and example rotary piston-type actuator in
example extended and retracted configurations.
[0032] FIG. 11 is a perspective view of another example of a rotary
piston-
type actuator.
[0033] FIGs. 12-14 are perspective and cross-sectional views of another
example rotary piston-type actuator.
[0034] FIGs. 15 and 16 are perspective and cross-sectional views of
another example rotary piston-type actuator that includes another example
rotary piston assembly.
[0035] FIGs. 17 and 18 are perspective and cross-sectional views of
another example rotary piston-type actuator that includes another example
rotary piston assembly.
[0036] FIGs. 19 and 20 are perspective and cross-sectional views of
another example rotary piston-type actuator.
[0037] FIGs. 21A-21C are cross-sectional and perspective views of an
example rotary piston.
[0038] FIGs. 22 and 23 illustrate a comparison of two example rotor shaft
embodiments.
[0039] FIG. 24 is a perspective view of another example rotary piston.
[0040] FIG. 25 is a flow diagram of an example process for performing
rotary actuation.
[0041] FIG. 26 is a perspective view of another example rotary piston-
type
actuator.
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[0042] FIG. 27 is a cross-sectional view of another example rotary piston
assembly.
[0043] FIG. 28 is a perspective cross-sectional view of another example
rotary piston-type actuator.
[0044] FIG 29A is a perspective view from above of an example rotary-
piston type actuator with a central actuation assembly.
[0045] FIG 29B is a top view of the actuator of FIG 29A.
[0046] FIG 29C is a perspective view from the right side and above
illustrating the actuator of FIG. 29A with a portion of the central actuation
io assembly removed for illustration purposes.
[0047] FIG 29D is a lateral cross section view taken at section AA of the
actuator of Fig 29B.
[0048] FIG. 29E is a partial perspective view from cross section AA of
FIG.
29B.
[0049] FIG. 30A is a perspective view from above of an example rotary
actuator with a central actuation assembly.
[0050] FIG. 30B is another perspective view from above of the example
rotary actuator of FIG. 30A.
[0051] FIG. 30C is a top view of the example rotary actuator of FIG. 30A.
[0052] FIG. 30D is an end view of the example rotary actuator of FIG. 30A.
[0053] FIG. 30E is a partial perspective view from cross section AA of
FIG.
30C.
[0054] FIG. 31A is a perspective view from above of another example
rotary actuator with a central actuation assembly.
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[0055] FIG. 31B is another perspective view from above of the example
rotary actuator of FIG. 31A.
[0056] FIG. 31C is a top view of the example rotary actuator of FIG. 31A.
[0057] FIG. 31D is an end view of the example rotary actuator of FIG.
31A.
[0058] FIG. 31E is a partial perspective view from cross section AA of FIG.
31C.
[0059] FIG. 32 is an exploded perspective view of another example
pressure chamber assembly.
[0060] FIGs. 33A-33C are exploded and assembled perspective views of
io another example rotary piston assembly.
[0061] FIGs. 34A and 34B are perspective views of another example rotary
piston.
[0062] FIG. 35A is a perspective view of another example pressure
chamber assembly.
[0063] FIG. 35B is a perspective partial cutaway view of the example
pressure chamber assembly of FIG. 35A.
[0064] FIG. 35C is a perspective exploded view of the example pressure
chamber assembly of FIG. 35A.
[0065] FIG. 36 is a perspective view of an example piston housing
assembly.
[0066] FIG. 37 is a schematic of an example rotary piston-type actuator
system.
[0067] FIG. 38 is a flow diagram of an example process for using the
example rotary piston-type actuator system of FIG. 37.
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[0068] FIG. 39 is a schematic of another example rotary piston-type
actuator system.
[0069] FIG. 40 is a flow diagram of an example process for using the
example rotary piston-type actuator system of FIG. 39.
[0070] FIG. 41 is a schematic of another example rotary piston-type
actuator system.
[0071] FIG. 42 is a flow diagram of an example process for using the
example rotary piston-type actuator system of FIG. 41.
[0072] FIG. 43 is a schematic of another example rotary piston-type
io actuator system.
[0073] FIG. 44 is a flow diagram of an example process for using the
example rotary piston-type actuator system of FIG. 43.
[0074] FIG. 45 is a schematic of another example rotary piston-type
actuator system.
[0075] FIG. 46 is a schematic of another example rotary piston-type
actuator system.
[0076] FIG. 47 is a schematic of another example rotary piston-type
actuator system.
[0077] FIG. 48 is a schematic of another example rotary piston-type
actuator system.
DETAILED DESCRIPTION
[0078] This document describes devices for producing rotary motion. In
particular, this document describes devices that can convert fluid
displacement
into rotary motion through the use of components more commonly used for
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producing linear motion, e.g., hydraulic or pneumatic linear cylinders. Vane-
type rotary actuators are relatively compact devices used to convert fluid
motion into rotary motion. Rotary vane actuators (RVA), however, generally
use seals and component configurations that exhibit cross-vane leakage of the
driving fluid. Such leakage can affect the range of applications in which such
designs can be used. Some applications may require a rotary actuator to hold
a rotational load in a selected position for a predetermined length of time,
substantially without rotational movement (e.g., less than 5 degrees of
movement), when the actuator's fluid ports are blocked. For example, some
io aircraft applications may require that an actuator hold a flap or other
control
surface that is under load (e.g., through wind resistance, gravity or g-
forces) at
a selected position when the actuator's fluid ports are blocked. Cross-vane
leakage, however, can allow movement from the selected position.
[0079] Linear pistons use relatively mature sealing technology that
exhibits
well-understood dynamic operation and leakage characteristics that are
generally better than rotary vane actuator type seals. Linear pistons,
however,
require additional mechanical components in order to adapt their linear
motions to rotary motions. Such linear-to-rotary mechanisms are generally
larger and heavier than rotary vane actuators that are capable of providing
similar rotational actions, e.g., occupying a larger work envelope. Such
linear-
to-rotary mechanisms may also generally be installed in an orientation that is
different from that of the load they are intended to drive, and therefore may
provide their torque output indirectly, e.g., installed to push or pull a
lever arm
that is at a generally right angle to the axis of the axis of rotation of the
lever
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arm. Such linear-to-rotary mechanisms may therefore become too large or
heavy for use in some applications, such as aircraft control where space and
weight constraints may make such mechanisms impractical for use.
[0080] In general, rotary piston assemblies use curved pressure chambers
and curved pistons to controllably push and pull the rotor arms of a rotor
assembly about an axis. In use, certain embodiments of the rotary piston
assemblies described herein can provide the positional holding characteristics
generally associated with linear piston-type fluid actuators, to rotary
applications, and can do so using the relatively more compact and lightweight
io envelopes generally associated with rotary vane actuators.
[0081] FIGs. 1-3 show various views of the components of an example
rotary piston-type actuator 100. Referring to FIG. 1, a perspective view of
the
example rotary piston-type actuator 100 is shown. The actuator 100 includes
a rotary piston assembly 200 and a pressure chamber assembly 300. The
actuator 100 includes a first actuation section 110 and a second actuation
section 120. In the example of actuator 100, the first actuation section 110
is
configured to rotate the rotary piston assembly 200 in a first direction,
e.g.,
counter-clockwise, and the second actuation section 120 is configured to
rotate the rotary piston assembly 200 in a second direction opposite the first
direction, e.g., clockwise.
[0082] Referring now to FIG. 2, a perspective view of the example rotary
piston assembly 200 is shown apart from the pressure chamber assembly 300.
The rotary piston assembly 200 includes a rotor shaft 210. A plurality of
rotor
arms 212 extend radially from the rotor shaft 210, the distal end of each
rotor
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arm 212 including a bore (not shown) substantially aligned (e.g., +/- 2
degrees)
with the axis of the rotor shaft 210 and sized to accommodate one of the
collection of connector pins 214.
[0083] As shown in FIG. 2, the first actuation section 110 includes a
pair of
rotary pistons 250, and the second actuation section 120 includes a pair of
rotary pistons 260. While the example actuator 100 includes two pairs of the
rotary pistons 250, 260, other embodiments can include greater and/or lesser
numbers of cooperative and opposing rotary pistons. Examples of other such
embodiments will be discussed below, for example, in the descriptions of FIGs.
4-25
[0084] In the example rotary piston assembly shown in FIG. 2, each of the
rotary pistons 250, 260 includes a piston end 252 and one or more connector
arms 254. The piston end 252 is formed to have a generally semi-circular
body having a substantially smooth surface (e.g., a surface quality that can
form a fluid barrier when in contact with a seal). Each of the connector arms
254 includes a bore 256 substantially aligned (e.g., +/- 2 degrees) with the
axis
of the semi-circular body of the piston end 252 and sized to accommodate one
of the connector pins 214.
[0085] The rotary pistons 260 in the example assembly of FIG. 2 are
oriented opposite each other in the same rotational direction. The rotary
pistons 250 are oriented opposite each other in the same rotational direction,
but opposite that of the rotary pistons 260. In some embodiments, the actuator
100 can rotate the rotor shaft 210 about 60 degrees total.
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[0086] Each of the rotary pistons 250, 260 of the example assembly of
FIG.
2 may be assembled to the rotor shaft 210 by aligning the connector arms 254
with the rotor arms 212 such that the bores (not shown) of the rotor arms 212
align with the bores 265. The connector pins 214 may then be inserted
through the aligned bores to create hinged connections between the pistons
250, 260 and the rotor shaft 210. Each connector pin 214 is slightly longer
than the aligned bores. In the example assembly, about the circumferential
periphery of each end of each connector pin 214 that extends beyond the
aligned bores is a circumferential recess (not shown) that can accommodate a
io retaining fastener (not shown), e.g., a snap ring or spiral ring.
[0087] FIG. 3 is a perspective cross-sectional view of the example rotary
piston-type actuator 100. The illustrated example shows the rotary pistons 260
inserted into a corresponding pressure chamber 310 formed as an arcuate
cavity in the pressure chamber assembly 300. The rotary pistons 250 are also
inserted into corresponding pressure chambers 310, not visible in this view.
[0088] In the example actuator 100, each pressure chamber 310 includes a
seal assembly 320 about the interior surface of the pressure chamber 310 at
an open end 330. In some implementations, the seal assembly 320 can be a
circular or semi-circular sealing geometry retained on all sides in a standard
seal groove. In some implementations, commercially available reciprocating
piston or cylinder type seals can be used. For example, commercially available
seal types that may already be in use for linear hydraulic actuators flying on
current aircraft may demonstrate sufficient capability for linear load and
position holding applications. In some implementations, the sealing complexity
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of the actuator 100 may be reduced by using a standard, e.g., commercially
available, semi-circular, unidirectional seal designs generally used in linear
hydraulic actuators. In some embodiments, the seal assembly 320 can be a
one-piece seal.
[0089] In some embodiments of the example actuator 100, the seal
assembly 320 may be included as part of the rotary pistons 250, 260. For
example, the seal assembly 320 may be located near the piston end 252,
opposite the connector arm 254, and slide along the interior surface of the
pressure chamber 310 to form a fluidic seal as the rotary piston 250, 260
io moves in and out of the pressure chamber 310. An example actuator that
uses such piston-mounted seal assemblies will be discussed in the
descriptions of FIGs. 26-28. In some embodiments, the seal 310 can act as a
bearing. For example, the seal assembly 320 may provide support for the
piston 250, 260 as it moves in and out of the pressure chamber 310.
[0090] In some embodiments, the actuator 100 may include a wear
member between the piston 250, 260 and the pressure chamber 310. For
example, a wear ring may be included in proximity to the seal assembly 320.
The wear ring may act as a pilot for the piston 250, 260, and/or act as a
bearing providing support for the piston 250, 260.
[0091] In the example actuator 100, when the rotary pistons 250, 260 are
inserted through the open ends 330, each of the seal assemblies 320 contacts
the interior surface of the pressure chamber 310 and the substantially smooth
surface (e.g., a surface quality that can form a fluid barrier when in contact
with
a seal) surface of the piston end 252 to form a substantially pressure-sealed
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(e.g., less than 10% pressure drop per hour) region within the pressure
chamber 310. Each of the pressure chambers 310 may include a fluid port
312 formed through the pressure chamber assembly 300, through which
pressurized fluid may flow. Upon introduction of pressurized fluid, e.g.,
hydraulic oil, water, air, gas, into the pressure chambers 310, the pressure
differential between the interior of the pressure chambers 310 and the ambient
conditions outside the pressure chambers 310 causes the piston ends 252 to
be urged outward from the pressure chambers 310. As the piston ends 252
are urged outward, the pistons 250, 260 urge the rotary piston assembly 200
io to rotate.
[0092] In the example of the actuator 100, cooperative pressure chambers
may be fluidically connected by internal or external fluid ports. For example,
the pressure chambers 310 of the first actuation section 110 may be
fluidically
interconnected to balance the pressure between the pressure chambers 310.
Similarly the pressure chambers 310 of the second actuation section 120 may
be fluidically interconnected to provide similar pressure balancing. In some
embodiments, the pressure chambers 310 may be fluidically isolated from
each other. For example, the pressure chambers 310 may each be fed by an
independent supply of pressurized fluid.
[0093] In the example of the actuator 100, the use of the alternating
arcuate, e.g., curved, rotary pistons 250, 260 arranged opposing each other
operates to translate the rotor arms in an arc-shaped path about the axis of
the
rotary piston assembly 200, thereby rotating the rotor shaft 210 clockwise and
counter-clockwise in a substantially (e.g., within 10%) torque balanced
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arrangement. Each cooperative pair of pressure chambers 310 operates uni-
directionally in pushing the respective rotary piston 250 outward, e.g.,
extension, to drive the rotor shaft 210 in the specific direction. To reverse
direction, the opposing cylinder section's 110 pressure chambers 260 are
pressurized to extend their corresponding rotary pistons 260 outward.
[0094] The pressure chamber assembly 300, as shown, includes a
collection of openings 350. In general, the openings 350 provide space in
which the rotor arms 212 can move when the rotor shaft 210 is partly rotated.
In some implementations, the openings 350 can be formed to remove material
io from the pressure chamber assembly 300, e.g., to reduce the mass of the
pressure chamber assembly 300. In some implementations, the openings 350
can be used during the process of assembly of the actuator 100. For example,
the actuator 100 can be assembled by inserting the rotary pistons 250, 260
through the openings 350 such that the piston ends 252 are inserted into the
pressure chambers 310. With the rotary pistons 250, 260 inserted into the
pressure chambers 310, the rotor shaft 210 can be assembled to (e.g.,
rotatably journaled within) the actuator 100 by aligning the rotor shaft 210
with
an axial bore 360 formed along the axis of the pressure chamber assembly
300, and by aligning the rotor arms 212 with a collection of keyways 362
formed along the axis of the pressure chamber assembly 300. The rotor shaft
210 can then be inserted into the pressure chamber assembly 300. The rotary
pistons 250, 260 can be partly extracted from the pressure chambers 310 to
substantially align the bores 256 with the bores of the rotor arms 212 (e.g.,
+/-
2 degrees). The connector pins 214 can then be passed through the keyways
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362 and the aligned bores to connect the rotary pistons 250, 260 to the rotor
shaft 210. The connector pins 214 can be secured longitudinally by inserting
retaining fasteners through the openings 350 and about the ends of the
connector pins 214. The rotor shaft 210 can be connected to an external
mechanism as an output shaft in order to transfer the rotary motion of the
actuator 100 to other mechanisms. A bushing or bearing 362 is fitted between
the rotor shaft 210 and the axial bore 360 at each end of the pressure chamber
assembly 300.
[0095] In some embodiments, the rotary pistons 250, 260 may urge rotation
io of the rotor shaft 210 by contacting the rotor arms 212. For example,
the
piston ends 252 may not be coupled to the rotor arms 212. Instead, the piston
ends 252 may contact the rotor arms 212 to urge rotation of the rotor shaft as
the rotary pistons 250, 260 are urged outward from the pressure chambers
310. Conversely, the rotor arms 212 may contact the piston ends 252 to urge
the rotary pistons 250, 260 back into the pressure chambers 310.
[0096] In some embodiments, a rotary position sensor assembly (not
shown) may be included in the actuator 100. For example, an encoder may be
used to sense the rotational position of the rotor shaft 210 relative to the
pressure chamber assembly or another feature that remains substantially
stationary (e.g., +1-5 degrees) relative to the rotation of the shaft 210. In
some
implementations, the rotary position sensor may provide signals that indicate
the position of the rotor shaft 210 to other electronic or mechanical modules,
e.g., a position controller.
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[0097] In use, pressurized fluid in the example actuator 100 can be
applied
to the pressure chambers 310 of the second actuation section 120 through the
fluid ports 312. The fluid pressure urges the rotary pistons 260 out of the
pressure chambers 310. This movement urges the rotary piston assembly 200
to rotate clockwise. Pressurized fluid can be applied to the pressure chambers
310 of the first actuation section 110 through the fluid ports 312. The fluid
pressure urges the rotary pistons 250 out of the pressure chambers 310. This
movement urges the rotary piston assembly 200 to rotate counter-clockwise.
The fluid conduits can also be blocked fluidically to cause the rotary piston
io assembly 200 to substantially maintain its rotary position relative to
the
pressure chamber assembly 300 (e.g., +1- 5 degrees).
[0098] In some embodiments of the example actuator 100, the pressure
chamber assembly 300 can be formed from a single piece of material. For
example, the pressure chambers 310, the openings 350, the fluid ports 312,
the keyways 362, and the axial bore 360 may be formed by molding,
machining, or otherwise forming a unitary piece of material.
[0099] FIG. 4 is a perspective view of another example rotary piston-type
actuator 400. In general, the actuator 400 is similar to the actuator 100, but
instead of using opposing pairs of rotary pistons 250, 260, each acting uni-
directionally to provide clockwise and counter-clockwise rotation, the
actuator
400 uses a pair of bidirectional rotary pistons.
[00100] As shown in FIG. 4, the actuator 400 includes a rotary piston
assembly that includes a rotor shaft 412 and a pair of rotary pistons 414. The
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rotor shaft 412 and the rotary pistons 414 are connected by a pair of
connector
pins 416.
[00101] The example actuator shown in FIG. 4 includes a pressure chamber
assembly 420. The pressure chamber assembly 420 includes a pair of
pressure chambers 422 formed as arcuate cavities in the pressure chamber
assembly 420. Each pressure chamber 422 includes a seal assembly 424
about the interior surface of the pressure chamber 422 at an open end 426.
The seal assemblies 424 contact the inner walls of the pressure chambers 422
and the rotary pistons 414 to form fluidic seals between the interiors of the
io pressure chambers 422 and the space outside. A pair of fluid ports 428
is in
fluidic communication with the pressure chambers 422. In use, pressurized
fluid can be applied to the fluid ports 428 to urge the rotary pistons 414
partly
out of the pressure chambers 422, and to urge the rotor shaft 412 to rotate in
a
first direction, e.g., clockwise in this example.
[00102] The pressure chamber assembly 420 and the rotor shaft 412 and
rotary pistons 414 of the rotary piston assembly may be structurally similar
to
corresponding components found in to the second actuation section 120 of the
actuator 100. In use, the example actuator 400 also functions substantially
similarly to the actuator 100 when rotating in a first direction when the
rotary
pistons 414 are being urged outward from the pressure chambers 422. e.g.,
clockwise in this example. As will be discussed next, the actuator 400 differs
from the actuator 100 in the way that the rotor shaft 412 is made to rotate in
a
second direction, e.g., counter-clockwise in this example.
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[00103] To provide actuation in the second direction, the example actuator
400 includes an outer housing 450 with a bore 452. The pressure chamber
assembly 420 is formed to fit within the bore 452. The bore 452 is fluidically
sealed by a pair of end caps (not shown). With the end caps in place, the bore
452 becomes a pressurizable chamber. Pressurized fluid can flow to and from
the bore 452 through a fluid port 454. Pressurized fluid in the bore 452 is
separated from fluid in the pressure chambers 422 by the seals 426.
[00104] Referring now to FIG. 5, the example actuator 400 is shown in a first
configuration in which the rotor shaft 412 has been rotated in a first
direction,
e.g., clockwise, as indicated by the arrows 501. The rotor shaft 412 can be
rotated in the first direction by flowing pressurized fluid into the pressure
chambers 422 through the fluid ports 428, as indicated by the arrows 502. The
pressure within the pressure chambers 422 urges the rotary pistons 414 partly
outward from the pressure chambers 422 and into the bore 452. Fluid within
the bore 452, separated from the fluid within the pressure chambers 422 by
the seals 424 and displaced by the movement of the rotary pistons 414, is
urged to flow out the fluid port 454, as indicated by the arrow 503.
[00105] Referring now to FIG. 6, the example actuator 400 is shown in a
second configuration in which the rotor shaft 412 has been rotated in a second
direction, e.g., counter-clockwise, as indicated by the arrows 601. The rotor
shaft 412 can be rotated in the second direction by flowing pressurized fluid
into the bore 452 through the fluid port 454, as indicated by the arrow 602.
The pressure within the bore 452 urges the rotary pistons 414 partly into the
pressure chambers 422 from the bore 452. Fluid within the pressure
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chambers 422, separated from the fluid within the bore 452 by the seals 424
and displaced by the movement of the rotary pistons 414, is urged to flow out
the fluid ports 428, as indicated by the arrows 603. In some embodiments,
one or more of the fluid ports 428 and 454 can be oriented radially relative
to
the axis of the actuator 400, as illustrated in FIGs. 4-6, however in some
embodiments one or more of the fluid ports 428 and 454 can be oriented
parallel to the axis of the actuator 400 or in any other appropriate
orientation.
[00106] FIG. 7 is a perspective view of another embodiment of a rotary
piston assembly 700. In the example actuator 100 of FIG. 1, two opposing
io pairs of rotary pistons were used, but in other embodiments other
numbers
and configurations of rotary pistons and pressure chambers can be used. In
the example of the assembly 700, a first actuation section 710 includes four
rotary pistons 712 cooperatively operable to urge a rotor shaft 701 in a first
direction. A second actuation section 720 includes four rotary pistons 722
cooperatively operable to urge the rotor shaft 701 in a second direction.
[00107] Although examples using four rotary pistons, e.g., actuator 100, and
eight rotary pistons, e.g., assembly 700, have been described, other
configurations may exist. In some embodiments, any appropriate number of
rotary pistons may be used in cooperation and/or opposition. In some
embodiments, opposing rotary pistons may not be segregated into separate
actuation sections, e.g., the actuation sections 710 and 720. While
cooperative pairs of rotary pistons are used in the examples of actuators 100,
400, and assembly 700, other embodiments exist. For example, clusters of
two, three, four, or more cooperative or oppositional rotary pistons and
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pressure chambers may be arranged radially about a section of a rotor shaft.
As will be discussed in the descriptions of FIGs. 8-10, a single rotary piston
may be located at a section of a rotor shaft. In some embodiments,
cooperative rotary pistons may be interspersed alternatingly with opposing
rotary pistons. For example, the rotary pistons 712 may alternate with the
rotary pistons 722 along the rotor shaft 701.
[00108] FIG. 8 is a perspective view of another example of a rotary piston-
type actuator 800. The actuator 800 differs from the example actuators 100
and 400, and the example assembly 700 in that instead of implementing
io cooperative pairs of rotary pistons along a rotor shaft, e.g., two of
the rotary
pistons 250 are located radially about the rotor shaft 210, individual rotary
pistons are located along a rotor shaft.
[00109] The example actuator 800 includes a rotor shaft 810 and a pressure
chamber assembly 820. The actuator 800 includes a first actuation section
801 and a second actuation section 802. In the example actuator 800, the first
actuation section 801 is configured to rotate the rotor shaft 810 in a first
direction, e.g., clockwise, and the second actuation section 802 is configured
to rotate the rotor shaft 810 in a second direction opposite the first
direction,
e.g., counter-clockwise.
[00110] The first actuation section 801 of example actuator 800 includes a
rotary piston 812, and the second actuation section 802 includes a rotary
piston 822. By implementing a single rotary piston 812, 822 at a given
longitudinal position along the rotor shaft 810, a relatively greater range of
rotary travel may be achieved compared to actuators that use pairs of rotary
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pistons at a given longitudinal position along the rotary piston assembly,
e.g.,
the actuator 100. In some embodiments, the actuator 800 can rotate the rotor
shaft 810 about 145 degrees total.
[00111] In some embodiments, the use of multiple rotary pistons 812, 822
along the rotor shaft 810 can reduce distortion of the pressure chamber
assembly 820, e.g., reduce bowing out under high pressure. In some
embodiments, the use of multiple rotary pistons 812, 822 along the rotor shaft
810 can provide additional degrees of freedom for each piston 812, 822. In
some embodiments, the use of multiple rotary pistons 812, 822 along the rotor
io shaft 810 can reduce alignment issues encountered during assembly or
operation. In some embodiments, the use of multiple rotary pistons 812, 822
along the rotor shaft 810 can reduce the effects of side loading of the rotor
shaft 810.
[00112] FIG. 9 shows the example actuator 800 with the rotary piston 812 in
an extended configuration. A pressurized fluid is applied to a fluid port 830
to
pressurize an arcuate pressure chamber 840 formed in the pressure chamber
assembly 820. Pressure in the pressure chamber 840 urges the rotary piston
812 partly outward, urging the rotor shaft 810 to rotate in a first direction,
e.g.,
clockwise.
[00113] FIG. 10 shows the example actuator 800 with the rotary piston 812
in a retracted configuration. Mechanical rotation of the rotor shaft 810,
e.g.,
pressurization of the actuation section 820, urges the rotary piston 812
partly
inward, e.g., clockwise. Fluid in the pressure chamber 840 displaced by the
rotary piston 812 flows out through the fluid port 830.
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[00114] The example actuator 800 can be assembled by inserting the rotary
piston 812 into the pressure chamber 840. Then the rotor shaft 810 can be
inserted longitudinally through a bore 850 and a keyway 851. The rotary
piston 812 is connected to the rotor shaft 810 by a connecting pin 852.
[00115] FIG. 11 is a perspective view of another example of a rotary piston-
type actuator 1100. In general, the actuator 1100 is similar to the example
actuator 800, except multiple rotary pistons are used in each actuation
section.
[00116] The example actuator 1100 includes a rotary piston assembly 1110
and a pressure chamber assembly 1120. The actuator 1100 includes a first
io actuation section 1101 and a second actuation section 1102. In the
example
of actuator 1100, the first actuation section 1101 is configured to rotate the
rotary piston assembly 1110 in a first direction, e.g., clockwise, and the
second
actuation section 1102 is configured to rotate the rotary piston assembly 1110
in a second direction opposite the first direction, e.g., counter-clockwise.
[00117] The first actuation section 1101 of example actuator 1100 includes a
collection of rotary pistons 812, and the second actuation section 1102
includes a collection of rotary pistons 822. By implementing individual rotary
pistons 812, 822 at various longitudinal positions along the rotary piston
assembly 1110, a range of rotary travel similar to the actuator 800 may be
achieved. In some embodiments, the actuator 1100 can rotate the rotor shaft
1110 about 60 degrees total.
[00118] In some embodiments, the use of the collection of rotary pistons 812
may provide mechanical advantages in some applications. For example, the
use of multiple rotary pistons 812 may reduce stress or deflection of the
rotary
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piston assembly, may reduce wear of the seal assemblies, or may provide
more degrees of freedom. In another example, providing partitions, e.g.,
webbing, between chambers can add strength to the pressure chamber
assembly 1120 and can reduce bowing out of the pressure chamber assembly
1120 under high pressure. In some embodiments, placement of an end tab on
the rotor shaft assembly 1110 can reduce cantilever effects experienced by the
actuator 800 while under load, e.g., less stress or bending.
[00119] FIGs. 12-14 are perspective and cross-sectional views of another
example rotary piston-type actuator 1200. The actuator 1200 includes a rotary
io piston assembly 1210, a first actuation section 1201, and a second
actuation
section 1202.
[00120] The rotary piston assembly 1210 of example actuator 1200 includes
a rotor shaft 1212, a collection of rotor arms 1214, and a collection of dual
rotary pistons 1216. Each of the dual rotary pistons 1216 includes a connector
section 1218 a piston end 1220a and a piston end 1220b. The piston ends
1220a-1220b are arcuate in shape, and are oriented opposite to each other in
a generally semicircular arrangement, and are joined at the connector section
1218. A bore 1222 is formed in the connector section 1218 and is oriented
substantially parallel (e.g., +/-5 degrees) to the axis of the semicircle
formed
by the piston ends 1220a-1220b. The bore 1222 is sized to accommodate a
connector pin (not shown) that is passed through the bore 1222 and a
collection of bores 1224 formed in the rotor arms 1213 to secure each of the
dual rotary pistons 1216 to the rotor shaft 1212.
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[00121] The first actuation section 1201 of example actuator 1200 includes a
first pressure chamber assembly 1250a, and the second actuation section
1202 includes a second pressure chamber assembly 1250b. The first
pressure chamber assembly 1250a includes a collection of pressure chambers
1252a formed as arcuate cavities in the first pressure chamber assembly
1250a. The second pressure chamber assembly 1250b includes a collection
of pressure chambers 1252b formed as arcuate cavities in the first pressure
chamber assembly 1250b. When the pressure chamber assemblies 1250a-
1250b are assembled into the actuator 1200, each of the pressure chambers
1252a lies generally in a plane with a corresponding one of the pressure
chambers 1252b, such that a pressure chamber 1252a and a pressure
chamber 1252b occupy two semicircular regions about a central axis. A
semicircular bore 1253a and a semicircular bore 1253b substantially align
(e.g., +1- 5 degrees) to accommodate the rotor shaft 1212.
[00122] Each of the pressure chambers 1252a-1252b of example actuator
1200 includes an open end 1254 and a seal assembly 1256. The open ends
1254 are formed to accommodate the insertion of the piston ends 1220a-
1220b. The seal assemblies 1256 contact the inner walls of the pressure
chambers 1252a-1252b and the outer surfaces of the piston ends 1220a-
1220b to form a fluidic seal.
[00123] The rotary piston assembly 1210 of example actuator 1200 can be
assembled by aligning the bores 1222 of the dual rotary pistons 1216 with the
bores 1224 of the rotor arms 1214. The connector pin (not shown) is passed
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through the bores 1222 and 1224 and secured longitudinally by retaining
fasteners.
[00124] The example actuator 1200 can be assembled by positioning the
rotor shaft 1212 abutting the semicircular bore 1253a and rotating it to
insert
the piston ends 1220a into the pressure chambers 1252a. The second
pressure chamber 1252b is positioned abutting the first pressure chamber
1252a such that the semicircular bore 1253b contacts the rotor shaft 1212.
The rotary piston assembly 1210 is then rotated to partly insert the piston
ends
1220b into the pressure chambers 1252b. An end cap 1260 is fastened to the
io longitudinal ends 1262a of the pressure chambers 1252a-1252b. A second
end cap (not shown) is fastened to the longitudinal ends 1262b of the pressure
chambers 1252a-1252b. The end caps substantially maintain the positions of
the rotary piston assembly 1210 and the pressure chambers 1252a-1252b
relative to each other (e.g., +/- 5 degrees). In some embodiments, the
actuator 1200 can provide about 90 degrees of total rotational stroke.
[00125] In operation, pressurized fluid is applied to the pressure chambers
1252a of example actuator 1200 to rotate the rotary piston assembly 1210 in a
first direction, e.g., clockwise. Pressurized fluid is applied to the pressure
chambers 1252b to rotate the rotary piston assembly 1210 in a second
direction, e.g., counter-clockwise.
[00126] FIGs. 15 and 16 are perspective and cross-sectional views of
another example rotary piston-type actuator 1500 that includes another
example rotary piston assembly 1501. In some embodiments, the assembly
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1501 can be an alternative embodiment of the rotary piston assembly 200 of
FIG. 2.
[00127] The assembly 1501 of example actuator 1500 includes a rotor shaft
1510 connected to a collection of rotary pistons 1520a and a collection of
rotary pistons 1520b by a collection of rotor arms 1530 and one or more
connector pins (not shown). The rotary pistons 1520a and 1520b are arranged
along the rotor shaft 1510 in a generally alternating pattern, e.g., one
rotary
piston 1520a, one rotary piston 1520b, one rotary piston 1520a, one rotary
piston 1520b. In some embodiments, the rotary pistons 1520a and 1520b may
io be arranged along the rotor shaft 1510 in a generally intermeshed
pattern,
e.g., one rotary piston 1520a and one rotary piston 1520b rotationally
parallel
to each other, with connector portions formed to be arranged side-by-side or
with the connector portion of rotary piston 1520a formed to one or more male
protrusions and/or one or more female recesses to accommodate one or more
corresponding male protrusions and/or one or more corresponding female
recesses formed in the connector portion of the rotary piston 1520b.
[00128] Referring to FIG. 16, a pressure chamber assembly 1550 of
example actuator 1500 includes a collection of arcuate pressure chambers
1555a and a collection of arcuate pressure chambers 1555b. The pressure
chambers 1555a and 1555b are arranged in a generally alternating pattern
corresponding to the alternating pattern of the rotary pistons 1520a-1520b.
The rotary pistons 1520a-1520b extend partly into the pressure chambers
1555a-1555b. A seal assembly 1560 is positioned about an open end 1565 of
each of the pressure chambers 1555a-1555b to form fluidic seals between the
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inner walls of the pressure chambers 1555a-1555b and the rotary pistons
1520a-1520b.
[00129] In use, pressurized fluid can be alternatingly provided to the
pressure chambers 1555a and 1555b of example actuator 1500 to urge the
rotary piston assembly 1501 to rotate partly clockwise and counterclockwise.
In some embodiments, the actuator 1500 can rotate the rotor shaft 1510 about
92 degrees total.
[00130] FIGs. 17 and 18 are perspective and cross-sectional views of
another example rotary piston-type actuator 1700 that includes another
io example rotary piston assembly 1701. In some embodiments, the assembly
1701 can be an alternative embodiment of the rotary piston assembly 200 of
FIG. 2 or the assembly 1200 of FIG. 12.
[00131] The assembly 1701 of example actuator 1700 includes a rotor shaft
1710 connected to a collection of rotary pistons 1720a by a collection of
rotor
arms 1730a and one or more connector pins 1732. The rotor shaft 1710 is
also connected to a collection of rotary pistons 1720b by a collection of
rotor
arms 1730b and one or more connector pins 1732. The rotary pistons 1720a
and 1720b are arranged along the rotor shaft 1710 in a generally opposing,
symmetrical pattern, e.g., one rotary piston 1720a is paired with one rotary
piston 1720b at various positions along the length of the assembly 1701.
[00132] Referring to FIG. 18, a pressure chamber assembly 1750 of
example actuator 1700 includes a collection of arcuate pressure chambers
1755a and a collection of arcuate pressure chambers 1755b. The pressure
chambers 1755a and 1755b are arranged in a generally opposing, symmetrical
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pattern corresponding to the symmetrical arrangement of the rotary pistons
1720a-1720b. The rotary pistons 1720a-1720b extend partly into the pressure
chambers 1755a-1755b. A seal assembly 1760 is positioned about an open
end 1765 of each of the pressure chambers 1755a-1755b to form fluidic seals
between the inner walls of the pressure chambers 1755a-1755b and the rotary
pistons 1720a-1720b.
[00133] In use, pressurized fluid can be alternatingly provided to the
pressure chambers 1755a and 1755b of example actuator 1700 to urge the
rotary piston assembly 1701 to rotate partly clockwise and counterclockwise.
io In some embodiments, the actuator 1700 can rotate the rotor shaft 1710
about
52 degrees total.
[00134] FIGs. 19 and 20 are perspective and cross-sectional views of
another example rotary piston-type actuator 1900. Whereas the actuators
described previously, e.g., the example actuator 100 of FIG. 1, are generally
elongated and cylindrical, the actuator 1900 is comparatively flatter and more
disk-shaped.
[00135] Referring to FIG. 19, a perspective view of the example rotary
piston-type actuator 1900 is shown. The actuator 1900 includes a rotary
piston assembly 1910 and a pressure chamber assembly 1920. The rotary
piston assembly 1910 includes a rotor shaft 1912. A collection of rotor arms
1914 extend radially from the rotor shaft 1912, the distal end of each rotor
arm
1914 including a bore 1916 aligned substantially parallel (e.g., +1-2 degrees)
with the axis of the rotor shaft 1912 and sized to accommodate one of a
collection of connector pins 1918.
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[00136] The rotary piston assembly 1910 of example actuator 1900 includes
a pair of rotary pistons 1930 arranged substantially symmetrically opposite
each other across the rotor shaft 1912. In the example of the actuator 1900,
the rotary pistons 1930 are both oriented in the same rotational direction,
e.g.,
the rotary pistons 1930 cooperatively push in the same rotational direction.
In
some embodiments, a return force may be provided to rotate the rotary piston
assembly 1910 in the direction of the rotary pistons 1930. For example, the
rotor shaft 1912 may be coupled to a load that resists the forces provided by
the rotary pistons 1930, such as a load under gravitational pull, a load
exposed
io to wind or water resistance, a return spring, or any other appropriate
load that
can rotate the rotary piston assembly. In some embodiments, the actuator
1900 can include a pressurizable outer housing over the pressure chamber
assembly 1920 to provide a back-drive operation , e.g., similar to the
function
provided by the outer housing 450 in FIG. 4. In some embodiments, the
actuator 1900 can be rotationally coupled to an oppositely oriented actuator
1900 that can provide a back-drive operation.
[00137] In some embodiments, the rotary pistons 1930 can be oriented in
opposite rotational directions, e.g., the rotary pistons 1930 can oppose each
other push in the opposite rotational directions to provide bidirectional
motion
control. In some embodiments, the actuator 100 can rotate the rotor shaft
about 60 degrees total.
[00138] Each of the rotary pistons 1930 of example actuator 1900 includes a
piston end 1932 and one or more connector arms 1934. The piston end 1932
is formed to have a generally semi-circular body having a substantially smooth
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surface. Each of the connector arms 1934 includes a bore 1936 (see FIGs.
21B and 21C) substantially aligned (e.g., +1- 2 degrees) with the axis of the
semi-circular body of the piston end 1932 and sized to accommodate one of
the connector pins 1918.
[00139] Each of the rotary pistons 1930 of example actuator 1900 is
assembled to the rotor shaft 1912 by aligning the connector arms 1934 with
the rotor arms 1914 such that the bores 1916 of the rotor arms 1914 align with
the bores 1936. The connector pins 1918 are inserted through the aligned
bores to create hinged connections between the pistons 1930 and the rotor
io shaft 1912. Each connector pin 1916 is slightly longer than the aligned
bores.
About the circumferential periphery of each end of each connector pin 1916
that extends beyond the aligned bores is a circumferential recess (not shown)
that can accommodate a retaining fastener (not shown), e.g., a snap ring or
spiral ring.
[00140] Referring now to FIG. 20 a cross-sectional view of the example
rotary piston-type actuator 1900 is shown. The illustrated example shows the
rotary pistons 1930 partly inserted into a corresponding pressure chamber
1960 formed as an arcuate cavity in the pressure chamber assembly 1920.
[00141] Each pressure chamber 1960 of example actuator 1900 includes a
seal assembly 1962 about the interior surface of the pressure chamber 1960 at
an open end 1964. In some embodiments, the seal assembly 1962 can be a
circular or semi-circular sealing geometry retained on all sides in a standard
seal groove.
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[00142] When the rotary pistons 1930 of example actuator 1900 are inserted
through the open ends 1964, each of the seal assemblies 1962 contacts the
interior surface of the pressure chamber 1960 and the substantially smooth
surface of the piston end 1932 to form a substantially pressure-sealed region
(e.g., less than 10% pressure drop per hour) within the pressure chamber
1960. Each of the pressure chambers 1960 each include a fluid port (not
shown) formed through the pressure chamber assembly 1920, through with
pressurized fluid may flow.
[00143] Upon introduction of pressurized fluid, e.g., hydraulic oil, water,
air,
gas, into the pressure chambers 1960 of example actuator 1900, the pressure
differential between the interior of the pressure chambers 1960 and the
ambient conditions outside the pressure chambers 1960 causes the piston
ends 1932 to be urged outward from the pressure chambers 1960. As the
piston ends 1932 are urged outward, the pistons 1930 urge the rotary piston
assembly 1910 to rotate.
[00144] In the illustrated example actuator 1900, each of the rotary pistons
1930 includes a cavity 1966. FIGs. 21A-21C provide additional cross-sectional
and perspective views of one of the rotary pistons 1930. Referring to FIG.
21A,
a cross-section the rotary piston 1930, taken across a section of the piston
end
1932 is shown. The cavity 1966 is formed within the piston end 1932.
Referring to FIG. 21 B, the connector arm 1934 and the bore 1936 is shown in
perspective. FIG. 21C features a perspective view of the cavity 1966.
[00145] In some embodiments, the cavity 1966 may be omitted. For
example, the piston end 1932 may be solid in cross-section. In some
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embodiments, the cavity 1966 may be formed to reduce the mass of the rotary
piston 1930 and the mass of the actuator 1900. For example, the actuator
1900 may be implemented in an aircraft application, where weight may play a
role in actuator selection. In some embodiments, the cavity 1966 may reduce
wear on seal assemblies, such as the seal assembly 320 of FIG. 3. For
example, by reducing the mass of the rotary piston 1930, the amount of force
the piston end 1932 exerts upon the corresponding seal assembly may be
reduced when the mass of the rotary piston is accelerated, e.g., by gravity or
G-forces.
[00146] In some embodiments, the cavity 1966 may be hollow in cross-
section, and include one or more structural members, e.g., webs, within the
hollow space. For example, structural cross-members may extend across the
cavity of a hollow piston to reduce the amount by which the piston may
distort,
e.g., bowing out, when exposed to a high pressure differential across the seal
assembly.
[00147] FIGs. 22 and 23 illustrate a comparison of two example rotor shaft
embodiments. FIG. 22 is a perspective view of an example rotary piston-type
actuator 2200. In some embodiments, the example actuator 2200 can be the
example actuator 1900.
[00148] The example actuator 2200 includes a pressure chamber assembly
2210 and a rotary piston assembly 2220. The rotary piston assembly 2220
includes at least one rotary piston 2222 and one or more rotor arms 2224. The
rotor arms 2224 extend radially from a rotor shaft 2230.
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[00149] The rotor shaft 2230 of example actuator includes an output section
2232 and an output section 2234 that extend longitudinally from the pressure
chamber assembly 2210. The output sections 2232-2234 include a collection
of splines 2236 extending radially from the circumferential periphery of the
output sections 2232-2234. In some implementations, the output section 2232
and/or 2234 may be inserted into a correspondingly formed splined assembly
to rotationally couple the rotor shaft 2230 to other mechanisms. For example,
by rotationally coupling the output section 2232 and/or 2234 to an external
assembly, the rotation of the rotary piston assembly 2220 may be transferred
io to urge the rotation of the external assembly.
[00150] FIG. 23 is a perspective view of another example rotary piston-type
actuator 2300. The actuator 2300 includes the pressure chamber assembly
2210 and a rotary piston assembly 2320. The rotary piston assembly 2320
includes at least one of the rotary pistons 2222 and one or more of the rotor
arms 2224. The rotor arms 2224 extend radially from a rotor shaft 2330.
[00151] The rotor shaft 2330 of example actuator 2300 includes a bore 2332
formed longitudinally along the axis of the rotor shaft 2330. The rotor shaft
2330 includes a collection of splines 2336 extending radially inward from the
circumferential periphery of the bore 2332. In some embodiments, a
correspondingly formed splined assembly may be inserted into the bore 2332
to rotationally couple the rotor shaft 2330 to other mechanisms.
[00152] FIG. 24 is a perspective view of another example rotary piston 2400.
In some embodiments, the rotary piston 2400 can be the rotary piston 250,
260, 414, 712, 812, 822, 1530a, 1530b, 1730a, 1730b, 1930 or 2222.
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[00153] The example rotary piston 2400 includes a piston end 2410 and a
connector section 2420. The connector section 2420 includes a bore 2430
formed to accommodate a connector pin, e.g., the connector pin 214.
[00154] The piston end 2410 of example actuator 2400 includes an end
taper 2440. The end taper 2440 is formed about the periphery of a terminal
end 2450 of the piston end 2410. The end taper 2440 is formed at a radially
inward angle starting at the outer periphery of the piston end 2410 and ending
at the terminal end 2450. In some implementations, the end taper 2440 can
be formed to ease the process of inserting the rotary piston 2400 into a
io pressure chamber, e.g., the pressure chamber 310.
[00155] The piston end 2410 of example actuator 2400 is substantially
smooth surface (e.g., a surface quality that can form a fluid barrier when in
contact with a seal). In some embodiments, the smooth surface of the piston
end 2410 can provide a surface that can be contacted by a seal assembly.
For example, the seal assembly 320 can contact the smooth surface of the
piston end 2410 to form part of a fluidic seal, reducing the need to form a
smooth, fluidically sealable surface on the interior walls of the pressure
chamber 310.
[00156] In the illustrated example, the rotary piston 2400 is shown as having
a generally solid circular cross-section, whereas the rotary pistons piston
250,
260, 414, 712, 812, 822, 1530a, 1530b, 1730a, 1730b, 1930 or 2222 have
been illustrated as having various generally rectangular, elliptical, and
other
shapes, both solid and hollow, in cross section. In some embodiments, the
cross sectional dimensions of the rotary piston 2400, as generally indicated
by
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the arrows 2491 and 2492, can be adapted to any appropriate shape, e.g.,
square, rectangular, ovoid, elliptical, circular, and other shapes, both solid
and
hollow, in cross section.. In some embodiments, the arc of the rotary piston
2400, as generally indicated by the angle 2493, can be adapted to any
appropriate length. In some embodiments, the radius of the rotary piston
2400, as generally indicated by the line 2494, can be adapted to any
appropriate radius. In some embodiments, the piston end 2410 can be solid,
hollow, or can include any appropriate hollow formation. In some
embodiments, any of the previously mentioned forms of the piston end 2410
io can also be used as the piston ends 1220a and/or 1220b of the dual
rotary
pistons 1216 of FIG. 12.
[00157] FIG. 25 is a flow diagram of an example process 2500 for
performing rotary actuation. In some implementations, the process 2500 can
be performed by the rotary piston-type actuators 100, 400, 700, 800, 1200,
1500, 1700, 1900, 2200, 2300, and/or 2600 which will be discussed in the
descriptions of FIGs. 26-28.
[00158] At 2510, a rotary actuator is provided. The rotary actuator of
example actuator 2500 includes a first housing defining a first arcuate
chamber
including a first cavity, a first fluid port in fluid communication with the
first
cavity, an open end, and a first seal disposed about an interior surface of
the
open end, a rotor assembly rotatably journaled in the first housing and
including a rotary output shaft and a first rotor arm extending radially
outward
from the rotary output shaft, an arcuate-shaped first piston disposed in the
first
housing for reciprocal movement in the first arcuate chamber through the open
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end. The first seal, the first cavity, and the first piston define a first
pressure
chamber, and a first connector, coupling a first end of the first piston to
the first
rotor arm. For example, the actuator 100 includes the components of the
pressure chamber assembly 300 and the rotary piston assembly 200 included
in the actuation section 120.
[00159] At 2520, a pressurized fluid is applied to the first pressure chamber.
For example, pressurized fluid can be flowed through the fluid port 320 into
the
pressure chamber 310.
[00160] At 2530, the first piston is urged partially outward from the first
io pressure chamber to urge rotation of the rotary output shaft in a first
direction.
For example, a volume of pressurized fluid flowed into the pressure chamber
310 will displace a similar volume of the rotary piston 260, causing the
rotary
piston 260 to be partly urged out of the pressure cavity 310, which in turn
will
cause the rotor shaft 210 to rotate clockwise.
[00161] At 2540, the rotary output shaft is rotated in a second direction
opposite that of the first direction. For example, the rotor shaft 210 can be
rotated counter-clockwise by an external force, such as another mechanism, a
torque-providing load, a return spring, or any other appropriate source of
rotational torque.
[00162] At 2550, the first piston is urged partially into the first pressure
chamber to urge pressurized fluid out the first fluid port. For example, the
rotary piston 260 can be pushed into the pressure chamber 310, and the
volume of the piston end 252 extending into the pressure chamber 310 will
displace a similar volume of fluid, causing it to flow out the fluid port 312.
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[00163] In some embodiments, the example process 2500 can be used to
provide substantially constant power over stroke to a connected mechanism.
For example, as the actuator 100 rotates, there may be less than 10%
position-dependent variation in the torque delivered to a connected load.
[00164] In some embodiments, the first housing further defines a second
arcuate chamber comprising a second cavity, a second fluid port in fluid
communication with the second cavity, and a second seal disposed about an
interior surface of the open end, the rotor assembly also includes a second
rotor arm, the rotary actuator also includes an arcuate-shaped second piston
io disposed in said housing for reciprocal movement in the second arcuate
chamber, wherein the second seal, the second cavity, and the second piston
define a second pressure chamber, and a second connector coupling a first
end of the second piston to the second rotor arm. For example, the actuator
100 includes the components of the pressure chamber assembly 300 and the
rotary piston assembly 200 included in the actuation section 110.
[00165] In some embodiments, the second piston can be oriented in the
same rotational direction as the first piston. For example, the two pistons
260
are oriented to operate cooperatively in the same rotational direction. In
some
embodiments, the second piston can be oriented in the opposite rotational
direction as the first piston. For example, the rotary pistons 250 are
oriented to
operate in the opposite rotational direction relative to the rotary pistons
260.
[00166] In some embodiments, the actuator can include a second housing
and disposed about the first housing and having a second fluid port, wherein
the first housing, the second housing, the seal, and the first piston define a
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second pressure chamber. For example, the actuator 400 includes the outer
housing 450 that surrounds the pressure chamber assembly 420. Pressurized
fluid in the bore 452 is separated from fluid in the pressure chambers 422 by
the seals 426.
[00167] In some implementations, rotating the rotary output shaft in a second
direction opposite that of the first direction can include applying
pressurized
fluid to the second pressure chamber, and urging the second piston partially
outward from the second pressure chamber to urge rotation of the rotary
output shaft in a second direction opposite from the first direction. For
example, pressurized fluid can be applied to the pressure chambers 310 of the
first actuation section 110 to urge the rotary pistons 260 outward, causing
the
rotor shaft 210 to rotate counter-clockwise.
[00168] In some implementations, rotating the rotary output shaft in a second
direction opposite that of the first direction can include applying
pressurized
fluid to the second pressure chamber, and urging the first piston partially
into
the first pressure chamber to urge rotation of the rotary output shaft in a
second direction opposite from the first direction. For example, pressurized
fluid can be flowed into the bore 452 at a pressure higher than that of fluid
in
the pressure chambers 422, causing the rotary pistons 414 to move into the
pressure chambers 422 and cause the rotor shaft 412 to rotate counter-
clockwise.
[00169] In some implementations, rotation of the rotary output shaft can urge
rotation of the housing. For example, the rotary output shaft 412 can be held
rotationally stationary and the housing 450 can be allowed to rotate, and
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application of pressurized fluid in the pressure chambers 422 can urge the
rotary pistons 414 out of the pressure chambers 422, causing the housing 450
to rotate about the rotary output shaft 412.
[00170] FIGs. 26-28 show various views of the components of another
example rotary piston-type actuator 2600. In general, the actuator 2600 is
similar to the example actuator 100 of FIG. 1, except for the configuration of
the seal assemblies. Whereas the seal assembly 320 in the example actuator
100 remains substantially stationary (e.g., +1- 5 degrees) relative to the
pressure chamber 310 and is in sliding contact with the surface of the rotary
io piston 250, in the example actuator 2600, the seal configuration is
comparatively reversed as will be described below.
[00171] Referring to FIG. 26, a perspective view of the example rotary
piston-type actuator 2600 is shown. The actuator 2600 includes a rotary
piston assembly 2700 and a pressure chamber assembly 2602. The actuator
2600 includes a first actuation section 2610 and a second actuation section
2620. In the example of actuator 2600, the first actuation section 2610 is
configured to rotate the rotary piston assembly 2700 in a first direction,
e.g.,
counter-clockwise, and the second actuation section 2620 is configured to
rotate the rotary piston assembly 2700 in a second direction opposite the
first
direction, e.g., clockwise.
[00172] Referring now to FIG. 27, a perspective view of the example rotary
piston assembly 2700 is shown apart from the pressure chamber assembly
2602. The rotary piston assembly 2700 includes a rotor shaft 2710. A plurality
of rotor arms 2712 extend radially from the rotor shaft 2710, the distal end
of
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each rotor arm 2712 including a bore (not shown) substantially aligned (e.g.,
+/- 2 degrees) with the axis of the rotor shaft 2710 and sized to accommodate
one of a collection of connector pins 2714.
[00173] As shown in FIG. 27, the first actuation section 2710 of example
rotary piston assembly 2700 includes a pair of rotary pistons 2750, and the
second actuation section 2720 includes a pair of rotary pistons 2760. While
the example actuator 2600 includes two pairs of the rotary pistons 2750, 2760,
other embodiments can include greater and/or lesser numbers of cooperative
and opposing rotary pistons.
[00174] In the example rotary piston assembly shown in FIG. 27, each of the
rotary pistons 2750, 2760 includes a piston end 2752 and one or more
connector arms 2754. The piston end 252 is formed to have a generally semi-
circular body having a substantially smooth surface (e.g., a surface quality
that
can form a fluid barrier when in contact with a seal). Each of the connector
arms 2754 includes a bore 2756 substantially aligned (e.g., +/- 2 degrees)
with
the axis of the semi-circular body of the piston end 2752 and sized to
accommodate one of the connector pins 2714.
[00175] In some implementations, each of the rotary pistons 2750, 2760
includes a seal assembly 2780 disposed about the outer periphery of the
piston ends 2752. In some implementations, the seal assembly 2780 can be a
circular or semi-circular sealing geometry retained on all sides in a standard
seal groove. In some implementations, commercially available reciprocating
piston or cylinder type seals can be used. For example, commercially available
seal types that may already be in use for linear hydraulic actuators flying on
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current aircraft may demonstrate sufficient capability for linear load and
position holding applications. In some implementations, the sealing complexity
of the actuator 2600 may be reduced by using a standard, e.g., commercially
available, semi-circular, unidirectional seal designs generally used in linear
hydraulic actuators. In some embodiments, the seal assembly 2780 can be a
one-piece seal.
[00176] FIG. 28 is a perspective cross-sectional view of the example rotary
piston-type actuator 2600. The illustrated example shows the rotary pistons
2760 inserted into a corresponding pressure chamber 2810 formed as an
arcuate cavity in the pressure chamber assembly 2602. The rotary pistons
2750 are also inserted into corresponding pressure chambers 2810, not visible
in this view.
[00177] In the example actuator 2600, when the rotary pistons 2750, 2760
are each inserted through an open end 2830 of each pressure chamber 2810,
each seal assembly 2780 contacts the outer periphery of the piston end 2760
and the substantially smooth interior surface of the pressure chamber 2810 to
form a substantially pressure-sealed (e.g., less than 10% pressure drop per
hour) region within the pressure chamber 2810.
[00178] In some embodiments, the seal 2780 can act as a bearing. For
example, the seal 2780 may provide support for the piston 2750, 2760 as it
moves in and out of the pressure chamber 310.
[00179] FIGs. 29A-29E are various views of another example rotary piston-
type actuator 2900 with a central actuation assembly 2960. For a brief
description of each drawing see the brief description of each of these
drawings
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included at the beginning of the Description of the Drawings section of this
document.
[00180] In general, the example rotary piston-type actuator 2900
substantially similar to the example rotary piston-type actuator 1200 of
FIGs.12-14, where the example rotary piston-type actuator 2900 also includes
a central actuation assembly 2960 and a central mounting assembly 2980.
Although the example rotary piston-type actuator 2900 is illustrated and
described as modification of the example rotary piston-type actuator 1200, in
some embodiments the example rotary piston-type actuator 2900 can
io implement features of any of the example rotary piston-type actuators
100,
400, 700, 800, 1200, 1500, 1700, 1900, 2200, 2300, and/or 2600 in a design
that also implements the central actuation assembly 2960 and/or the central
mounting assembly 2980.
[00181] The actuator 2900 includes a rotary piston assembly 2910, a first
actuation section 2901 and a second actuation section 2902. The rotary piston
assembly 2910 includes a rotor shaft 2912, a collection of rotor arms 2914,
and the collection of dual rotary pistons, e.g., the dual rotary pistons 1216
of
FIGs. 12-14.
[00182] The first actuation section 2901 of example actuator 2900 includes a
first pressure chamber assembly 2950a, and the second actuation section
2902 includes a second pressure chamber assembly 2950b. The first
pressure chamber assembly 2950a includes a collection of pressure
chambers, e.g., the pressure chambers 1252a of FIGs. 12-14, formed as
arcuate cavities in the first pressure chamber assembly 2950a. The second
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pressure chamber assembly 2950b includes a collection of pressure
chambers, e.g., the pressure chambers 1252b of FIGs. 12-14, formed as
arcuate cavities in the second pressure chamber assembly 2950b. A
semicircular bore 2953 in the housing accommodates the rotor shaft 2912.
[00183] The central mounting assembly 2980 is formed as a radially
projected portion 2981 of a housing of the second pressure chamber assembly
2950b. The central mounting assembly 2980 provides a mounting point for
removably affixing the example rotary piston-type actuator 2900 to an external
surface, e.g., an aircraft frame. A collection of holes 2982 formed in the
io radially projected section 2981 accommodate the insertion of a
collection of
fasteners 2984, e.g., bolts, to removably affix the central mounting assembly
2980 to an external mounting feature 2990, e.g., a mounting point (bracket) on
an aircraft frame.
[00184] The central actuation assembly 2960 includes a radial recess 2961
formed in a portion of an external surface of a housing of the first and the
second actuation sections 2901, 2902 at a midpoint along a longitudinal axis
AA to the example rotary piston-type actuator 2900. An external mounting
bracket 2970 that may be adapted for attachment to an external mounting
feature on a member to be actuated, (e.g., aircraft flight control surfaces)
is
connected to an actuation arm 2962. The actuation arm 2962 extends through
the recess 2961 and is removably attached to a central mount point 2964
formed in an external surface at a midpoint of the longitudinal axis of the
rotor
shaft 2912.
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[00185] Referring more specifically to FIGs. 29D and 29E now, the example
rotary piston-type actuator 2900 is shown in cutaway end and perspective
views taken though a midpoint of the central actuation assembly 2960 and the
central mounting assembly 2980 at the recess 2961. The actuation arm 2962
extends into the recess 2961 to contact the central mount point 2964 of the
rotor shaft 2912. The actuation arm 2962 is removably connected to the
central mount point 2964 by a fastener 2966, e.g., bolt, that is passed
through
a pair of holes 2968 formed in the actuation arm 2962 and a hole 2965 formed
through the central mount point 2964. A collection of holes 2969 are formed
io in a radially outward end of the actuation arm 2962. A collection of
fasteners
2972, e.g., bolts, are passed through the holes 2969 and corresponding holes
(not shown) formed in an external mounting feature (bracket) 2970. As
mentioned above, the central actuation assembly 2960 connects the example
rotary piston actuator 2900 to the external mounting feature 2970 to transfer
rotational motion of the rotor assembly 2910 to equipment to be moved
(actuated), e.g., aircraft flight control surfaces.
[00186] In some embodiments, one of the central actuation assembly 2960
or the central mounting assembly 2980 can be used in combination with
features of any of the example rotary piston-type actuators 100, 400, 700,
800,
1200, 1500, 1700, 1900, 2200, 2300, and/or 2600. For example, the example
rotary piston-type actuator 2900 may be mounted to a stationary surface
through the central mounting assembly 2980, and provide actuation at one or
both ends of the rotor shaft assembly 2910. In another example, the example
rotary piston assembly 2900 may be mounted to a stationary surface through
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non-central mounting points, and provide actuation at the central actuation
assembly 2960.
[00187] FIGs. 30A-30E are various views of an example rotary actuator 3000
with a central actuation assembly 3060. For a brief description of each
drawing
see the brief description of each of these drawings included at the beginning
of
the Description of the Drawings section of this document.
[00188] In general, the example rotary actuator 3000 is substantially similar
to the rotary piston-type actuator 2900 of FIGs. 29A-29E, where the example
rotary actuator 3000 also includes a central actuation assembly 3060 and a
io central mounting assembly 3080. In some embodiments, the example rotary
actuator 3000 can be a modification of the example rotary piston-type actuator
2900 in which rotational action can be performed by a mechanism other than a
rotary piston-type actuator. For example, the example rotary actuator 3000
can be include a rotary vane type actuator, a rotary fluid type actuator, an
electromechanical actuator, a linear-to-rotary motion actuator, or
combinations
of these or any other appropriate rotary actuator. Although the example rotary
actuator 3000 is illustrated and described as modification of the example
rotary
piston-type actuator 2900, in some embodiments the example rotary actuator
3000 can implement features of any of the example rotary piston-type
actuators 100, 400, 700, 800, 1200, 1500, 1700, 1900, 2200, 2300, 2600
and/or 2900 in a design that also implements the central actuation assembly
3060 and/or the central mounting assembly 3080.
[00189] The actuator 3000 includes a rotary actuator section 3010a and a
rotary actuator section 3010b. In some embodiments, the rotary actuator
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sections 3010a and 3010b can be rotary vane type actuators, a rotary fluid
type actuators, electromechanical actuators, a linear-to-rotary motion
actuators, or combinations of these or any other appropriate rotary actuators.
The rotary actuator section 3010a includes a housing 3050a, and the rotary
actuator section 3010b includes a housing 3050b. A rotor shaft 3012a runs
along the longitudinal axis of the rotary actuator section 3010a, and a rotor
shaft 3012b runs along the longitudinal axis of the rotary actuator section
3010b.
[00190] The central mounting assembly 3080 is formed as a radially
io projected portion 3081 of the housings 3050a and 3050b. The central
mounting assembly 3080 provides a mounting point for removably affixing the
example rotary actuator 3000 to an external surface or an external structural
member, e.g., an aircraft frame, an aircraft control surface. A collection of
holes 3082 formed in the radially projected section 3081 accommodate the
insertion of a collection of fasteners (not shown), e.g., bolts, to removably
affix
the central mounting assembly 3080 to an external mounting feature, e.g., the
external mounting feature 2090 of FIG. 29, a mounting point (bracket) on an
aircraft frame or control surface.
[00191] The central actuation assembly 3060 includes a radial recess 3061
formed in a portion of an external surfaces of the housings 3050a, 3050b at a
midpoint along a longitudinal axis AA to the example rotary actuator 3000. In
some implementations, an external mounting bracket, such as the external
mounting bracket 2970, may be adapted for attachment to an external
mounting feature of a structural member or a member to be actuated, (e.g.,
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aircraft flight control surfaces) can be connected to an actuation arm 3062.
An
actuation arm, such as the actuation arm 2962, can extend through the recess
3061 and can be removably attached to a central mount point 3064 formed in
an external surface at a midpoint of the longitudinal axis of the rotor shafts
3012a and 3012b.
[00192] Referring more specifically to FIGs. 30D and 30E now, the example
rotary piston-type actuator 3000 is shown in end and cutaway perspective
views taken though a midpoint of the central actuation assembly 3060 and the
central mounting assembly 3080 at the recess 3061. The actuation arm (not
io shown) can extend into the recess 3061 to contact the central mount
point
3064 of the rotor shafts 3012a, 3012b. The actuation arm can be removably
connected to the central mount point 3064 by a fastener, e.g., bolt, that can
be
passed through a pair of holes (e.g. the holes 2968 formed in the actuation
arm 2962) and a hole 3065 formed through the central mount point 3064.
Similarly to as was discussed in the description of the rotary piston-type
actuator 2900 and the central actuation assembly 2960, the central actuation
assembly 3060 connects the example rotary actuator 3000 to an external
mounting feature or structural member to impart rotational motion of the
actuator sections 3010a, 3010b to equipment to be moved (actuated), e.g.,
aircraft flight control surfaces, relative to structural members, e.g.,
aircraft
frames.
[00193] In some embodiments, one of the central actuation assembly 3060
or the central mounting assembly 3080 can be used in combination with
features of any of the example rotary piston-type actuators 100, 400, 700,
800,
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1200, 1500, 1700, 1900, 2200, 2300, 2600 and/or 2900. For example, the
example rotary actuator 3000 may be mounted to a stationary surface through
the central mounting assembly 3080, and provide actuation at one or both
ends of the rotor shafts 3012a, 3012b. In another example, the example rotary
actuator 3000 may be mounted to a stationary surface through non-central
mounting points, and provide actuation at the central actuation assembly 3060.
In another example, the rotary actuator 3000 may be mounted to a stationary
surface through the central mount point 3064, and provide actuation at the
central mounting assembly 3080.
[00194] FIGs. 31A-31E are various views of an example rotary actuator 3100
with a central actuation assembly 3160. For a brief description of each
drawing
see the brief description of each of these drawings included at the beginning
of
the Description of the Drawings section of this document.
[00195] In general, the example rotary actuator 3100 is substantially similar
to the rotary actuator 3000 of FIGs. 30A-30E, where the example rotary
actuator 3100 also includes a central actuation assembly 3160 and a central
mounting assembly 3180. In some embodiments, the example rotary actuator
3100 can be a modification of the example rotary piston-type actuator 3000 in
which rotational action can be performed by a mechanism other than a rotary
fluid actuator. The example rotary actuator 3100 is an electromechanical
actuator. Although the example rotary actuator 3100 is illustrated and
described as modification of the example rotary actuator 3000, in some
embodiments the example rotary actuator 3100 can implement features of any
of the example rotary piston-type actuators 100, 400, 700, 800, 1200, 1500,
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1700, 1900, 2200, 2300, 2600 and/or 2900 and/or the rotary actuator 3000 in a
design that also implements the central actuation assembly 3160 and/or the
central mounting assembly 3180.
[00196] The actuator 3100 includes a rotary actuator section 3110a and a
rotary actuator section 3110b. In some embodiments, the rotary actuator
sections 3110a and 3110b can be electromechanical actuators. The rotary
actuator section 3110a includes a housing 3150a, and the rotary actuator
section 3110b includes a housing 3150b. A rotor shaft 3112a runs along the
longitudinal axis of the rotary actuator section 3110a, and a rotor shaft
3112b
io runs along the longitudinal axis of the rotary actuator section 3110b.
[00197] The central mounting assembly 3180 is formed as a radially
projected portion 3181 of the housings 3150a and 3150b. The central
mounting assembly 3180 provides a mounting point for removably affixing the
example rotary actuator 3100 to an external surface or an external structural
member, e.g., an aircraft frame, an aircraft control surface. A collection of
holes 3182 formed in the radially projected section 3181 accommodate the
insertion of a collection of fasteners (not shown), e.g., bolts, to removably
affix
the central mounting assembly 3180 to an external mounting feature, e.g., the
external mounting feature 2090 of FIG. 29, a mounting point (bracket) on an
aircraft frame or control surface.
[00198] The central actuation assembly 3160 includes a radial recess 3161
formed in a portion of an external surfaces of the housings 3150a, 3150b at a
midpoint along a longitudinal axis AA to the example rotary actuator 3100. In
some implementations, an external mounting bracket, such as the external
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mounting bracket 2970, may be adapted for attachment to an external
mounting feature of a structural member or a member to be actuated, (e.g.,
aircraft flight control surfaces) can be connected to an actuation arm 3162.
An
actuation arm, such as the actuation arm 2962, can extend through the recess
3161 and can be removably attached to a central mount point 3164 formed in
an external surface at a midpoint of the longitudinal axis of the rotor shafts
3112a and 3112b.
[00199] Referring more specifically to FIGs. 31D and 31E now, the example
rotary piston-type actuator 3100 is shown in end and cutaway perspective
io views taken though a midpoint of the central actuation assembly 3160 and
the
central mounting assembly 3080 at the recess 3161. The actuation arm (not
shown) can extend into the recess 3161 to contact the central mount point
3164 of the rotor shafts 3112a, 3112b. The actuation arm can be removably
connected to the central mount point 3164 by a fastener, e.g., bolt, that can
be
passed through a pair of holes (e.g. the holes 2968 formed in the actuation
arm 2962) and a hole 3165 formed through the central mount point 3164.
Similarly to as was discussed in the description of the rotary piston-type
actuator 2900 and the central actuation assembly 2960, the central actuation
assembly 3160 connects the example rotary actuator 3100 to an external
mounting feature or structural member to impart rotational motion of the
actuator sections 3110a, 3110b to equipment to be moved (actuated), e.g.,
aircraft flight control surfaces, relative to structural members, e.g.,
aircraft
frames.
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[00200] In some embodiments, one of the central actuation assembly 3160
or the central mounting assembly 3180 can be used in combination with
features of any of the example rotary piston-type actuators 100, 400, 700,
800,
1200, 1500, 1700, 1900, 2200, 2300, 2600 and/or 2900 and/or the rotary
actuator 3000. For example, the example rotary actuator 3100 may be
mounted to a stationary surface through the central mounting assembly 3180,
and provide actuation at one or both ends of the rotor shafts 3112a, 3112b. In
another example, the example rotary actuator 3100 may be mounted to a
stationary surface through non-central mounting points, and provide actuation
io at the central actuation assembly 3160. In another example, the rotary
actuator 3100 may be mounted to a stationary surface through the central
mount point 3164, and provide actuation at the central mounting assembly
3180.
[00201] FIG. 32 is an exploded perspective view of another example
pressure chamber assembly 3200. In some embodiments, features of the
pressure chamber assembly 3200 can be used with any of the actuators 400,
800, 1200, 1500, 1750, 1900, 2200, 2300, and 2600. The pressure chamber
assembly 3200 includes a housing 3210, a modular piston housing 3250a, and
a modular piston housing 3250b. The housing 3210 includes a central
longitudinal cavity 3212. The central longitudinal cavity 3212 is formed to
accommodate a rotor shaft (not shown) such as the rotor shaft 210 of the
rotary piston assembly 200 of FIG. 2.
[00202] The modular piston housing 3250a of example pressure chamber
assembly 3200 is an arcuate-shaped assembly that includes a collection of
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pressure chambers 3252a formed as arcuate cavities in the modular piston
housing 3250a. Similarly, the modular piston housing 3250b is also an
arcuate-shaped assembly that includes a collection of pressure chambers
3252b formed as arcuate cavities in the modular piston housing 3250b. In the
illustrated example, the modular piston housing 3250b mirrors the arcuate
shape of the modular piston housing 3250a. The pressure chambers 3252a,
3252b are formed to accommodate rotary pistons (not shown) such as rotary
pistons 250. In some implementations, the modular piston housings 3250a,
3250b can be formed as unitary piston housings. For example, the modular
io piston housings 3250a, 3250b may each be machined, extruded, or
otherwise
formed without forming seams within the pressure chambers 3251a, 3252b.
[00203] In the assembled form of the example pressure chamber assembly
3200, the modular piston housings 3250a, 3250b are removably affixed to the
housing 3210. In some embodiments, the pressure chamber assembly 3200
can include radial apertures into which the modular piston housings 3250a,
3250b can be inserted. In some embodiments, the pressure chamber
assembly 3200 can include longitudinal apertures into which the modular
piston housings 3250a, 3250b can be inserted.
[00204] The modular piston housings 3250a, 3250b of example pressure
chamber assembly 3200 include a collection of bores 3254. In the assembled
form of the pressure chamber assembly 3200 the bores 3254 align with a
collection of bores 3256 formed in the housing 3210, a collection of fasteners
(not shown), e.g., bolts or screws, are passed through the bores 3256 and into
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the bores 3254 to removably affix the modular piston housings 3250a, 3250b
to the housing 3210.
[00205] In some embodiments, modular piston housings 3250a, 3250b can
include a seal assembly about the interior surface of the pressure chambers
3252a, 3252b. In some embodiments, the seal assembly can be a circular or
semi-circular sealing geometry retained on all sides in a standard seal
groove.
In some embodiments, commercially available reciprocating piston or cylinder
type seals can be used. For example, commercially available seal types that
may already be in use for linear hydraulic actuators flying on current
aircraft
io may demonstrate sufficient capability for linear load and position
holding
applications. In some embodiments, the sealing complexity of the example
pressure chamber assembly 3200 may be reduced by using a standard, e.g.,
commercially available, semi-circular, unidirectional seal design generally
used
in linear hydraulic actuators. In some embodiments, the seal assemblies can
be a one-piece seal. In some embodiments of the modular piston housings
3250a, 3250b, the seal assemblies may be included as part of the rotary
pistons. In some embodiments, the modular piston housings 3250a, 3250b
may include a wear member between the pistons and the pressure chambers
3252a, 3252b.
[00206] Each of the pressure chambers 3252a, 3252b of example pressure
chamber assembly 3200 may include a fluid port (not shown) formed through
the modular piston housings 3250a, 3250b, through which pressurized fluid
may flow. Upon introduction of pressurized fluid (e.g., hydraulic oil, water,
air,
gas) into the pressure chambers 3252a, 3252b, the pressure differential
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between the interior of the pressure chambers 3252a, 3252b and the ambient
conditions outside the pressure chambers 3252a, 3252b can cause ends of
the pistons to be urged outward from the pressure chambers 3252a, 3252b.
As the piston ends are urged outward, the pistons urge a rotary piston
assembly, such as the rotary piston assembly 200, to rotate.
[00207] In some embodiments, the modular piston housings 3250a, 3250b
may include the central longitudinal cavity 3212 and other features of the
housing 3210. In some embodiments, the modular piston housings 3250a,
3250b may be removably affixed to each other. For example, the modular
io piston housings 3250a, 3250b may be bolted, screwed, clamped, welded,
pinned, or otherwise directly or indirectly retained relative to each other
such
that the assembled combination provides the features of the housing 3210,
eliminating the need for the housing 3210.
[00208] FIGs. 33A-33C are exploded and assembled perspective views of
another example rotary piston assembly 3300. In some embodiments,
features of the rotary piston assembly 3300 can be used with any of the rotary
piston assemblies 200, 700, 1100, 1501, 1701, and 2700, and/or with any of
the actuators 400, 800, 1200, 1500, 1750, 1900, 2200, 2300, 2600, 2900, and
3000. The rotary piston assembly 3300 includes a rotor shaft 3310. A plurality
of rotor arms 3312 extend radially from the rotor shaft 3310, the distal end
of
each rotor arm 3312 including a bore (not shown) substantially aligned (e.g.,
+/- 2 degrees) with the axis of the rotor shaft 3310 and sized to accommodate
one of a collection of connector pins 3314.
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[00209] The example rotary piston assembly 3300 includes a pair of rotary
pistons 3350. While the example rotary piston assembly 3300 includes two of
the rotary pistons 3350, other embodiments can include greater and/or lesser
numbers of cooperative and opposing rotary pistons. Each of the rotary
pistons 3350 includes a piston end 3352 and one or more connector arms
3354. The piston end 3352 is formed to have a generally semi-circular body
having a substantially smooth surface (e.g., a surface quality that can form a
fluid barrier when in contact with a seal). Each of the connector arms 3354
includes a bore 3356 substantially aligned (e.g., +/- 2 degrees) with the axis
of
io the semi-circular body of the piston end 3352 and sized to accommodate
one
of the connector pins 3314.
[00210] Each of the rotary pistons 3350 of the example rotary piston
assembly 3300 may be assembled to the rotor shaft 3310 by aligning the
connector arms 3354 with the rotor arms 3312 such that the bores (not shown)
of the rotor arms 3312 align with the bores 3365. The connector pins 3314
may then be inserted through the aligned bores to create connections between
the pistons 3350 and the rotor shaft 3310. As shown, each connector pin 3314
is slightly longer than the aligned bores. In the example assembly, about the
circumferential periphery of each end of each connector pin 3314 that extends
beyond the aligned bores is a circumferential recess (not shown) that can
accommodate a retaining fastener (not shown), e.g., a snap ring or spiral
ring.
[00211] The connections between the connector arms 3354 with the rotor
arms 3312, unlike embodiments such as the rotary piston assembly 200, are
not hinged. The connector arms 3312 include retainer elements 3380, and the
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rotor arms 3312 include retainer elements 3382. When the assembly 3300 is
in its assembled form, the retainer elements 3380, 3382 are intermeshed
relative to the rotary motion of the pistons 3350 and the rotor shaft 3310. In
some embodiments, the retainer elements 3380, 3382 can be formed with
radial geometries that prevent rotation of the rotary pistons 3350 away from
the radius of curvature of the rotary pistons 3350.
[00212] In the exemplary embodiment, contact among the retainer elements
3380, 3382 permits rotary movement to be transmitted between the rotor shaft
3310 and the rotary pistons 3350. Movement of the pistons 3350 urges motion
io of the rotor arms 3312 and the rotor shaft 3310 through contact among
the
retainer elements 3380, 3382. Likewise, movement of the rotor shaft 3310 and
the rotor arms 3312 urges motion of the pistons 3350 through contact among
the retainer elements 3380, 3382. In some embodiments, the retainer
elements 3380, 3382 can be connected by one or more fasteners that prevent
rotation of the rotary pistons 3350 away from the radius of curvature of the
rotary pistons 3350. For example, the retainer elements 3380, 3382 can be
connected by bolts, screws, clamps, welds, adhesives, or any other
appropriate form of connector or fastener.
[00213] In the example rotary piston assembly 3300, contact among the
retainer elements 3380, 3382 permits rotary movement to be transmitted
between the rotor shaft 3310 and the rotary pistons 3350 even if the connector
pin 3314 becomes broken or is missing. In some embodiments, the connector
pin 3314 may be longitudinally constrained by a piston housing (not shown).
For example, the connector pin 3314 may break at some point along its length,
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but the housing may be formed such that the ends of the connector pin 3314
may not have sufficient room to permit a broken section of the connector pin
3314 to move far enough longitudinally to become disengaged from the bores
3356. In some embodiments such as this, the retainer elements 3380, 3382
and/or the housing can provide a fail-safe construction that can prevent
broken
pieces of the connector pin 3314 from becoming dislodged from their normal
locations, which can present a risk of if such broken pieces were to become
jammed within components of a rotary actuator in which the rotary piston
assembly 3300 may be used.
[00214] In some embodiments, the connector pin 3314 and the bores 3356
and the bores (not shown) of the rotor arms 3312 can be formed with cross-
sectional geometries that prevent rotation of the connector pin 3314 within
the
bores 3356 and the bores (not shown) of the rotor arms 3312 around the
longitudinal axis of the connector pin 3314. For example, the connector pin
3314 can be a "locking pin" formed with a square, rectangular, triangular,
hex,
star, oval, or any other appropriate non-circular cross-section, and the bores
3356 and the bores (not shown) of the rotor arms 3312 are formed with
corresponding cross-sections, such that the connector pin 3314 can be
inserted when the bores are aligned and the pistons 3350 are substantially
prevented from rotating (e.g., less than 5 degrees of rotation) about the axis
of
the connector pin 3314 when the connector pin 3314 is inserted within the
bores.
[00215] In some embodiments, the retainer elements 3380, 3382 and/or the
"locking pin" embodiment of the connector pin 3314 can affect the performance
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of the rotary piston assembly 3300. For example, embodiments of the rotary
piston assembly 3300 implementing the retainer elements 3380, 3382 and/or
the "locking pin" embodiment of the connector pin 3314, can reduce or prevent
relative movement between the pistons 3350 and the rotor arms 3312 as the
rotary piston assembly 3300 moves within a rotary piston actuator, which can
provide substantially constant torque (e.g., less than 10% variance) over a
relatively full range of motion of the assembly 3300.
[00216] FIGs. 34A and 34B are perspective views of another example rotary
piston 3400. In some embodiments, the rotary piston 3400 can be the rotary
io piston 3350 of FIGs. 33A-33C. In some embodiments, features of the
rotary
piston 3400 can be used with any of the rotary piston assemblies 200, 700,
1100, 1501, 1701, and 2700, and/or with any of the actuators 400, 800, 1200,
1500, 1750, 1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300.
[00217] As shown in the example rotary piston of FIGs. 34A-34B, the rotary
piston 3400 includes a piston end 3432 and one or more connector arms 3434.
The piston end 3432 is formed to have a generally elliptical body having a
substantially smooth surface (e.g., a surface quality that can form a fluid
barrier when in contact with a seal). Each of the connector arms 3434
includes a bore 3436a and a bore 3436b substantially aligned (e.g., +/- 2
degrees) with the axis of the elliptical body of the piston end 3432 and sized
to
accommodate a connector pin such as one of the connector pins 3314. Other
embodiments may include more than two bores in a rotary piston. In other
embodiments, the piston end 3432 is formed to have a generally rectangular
body, or a body having any other appropriate cross-section.
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[00218] In some embodiments, the "multiple pin" embodiment of the rotary
piston 3400 can affect the performance of a rotary piston assembly. For
example, embodiments of rotary piston assemblies implementing the rotary
piston 3400, two locking pins, and a correspondingly formed rotor arm can
reduce or prevent relative movement between the piston 3400 and the rotor
arms as the rotary piston assembly moves within a rotary piston actuator,
which can provide substantially constant torque (e.g., less than 10% variance)
over a relatively full range of motion of the assembly.
[00219] In some embodiments, one or more of the bores 3436a, 3436b can
io be formed with cross-sectional geometries that prevent rotation of a
connector
pin, such as the connector pin 3314, within the bores 3436a, 3436b around the
longitudinal axis of the connector pin. For example, one or more of the bores
3436a, 3436b can be formed with square, rectangular, triangular, hex, star,
oval, or any other appropriate non-circular cross-sections, such that
correspondingly configured connector pins can be inserted to substantially
prevent the rotary piston 3400 from rotating about the axes of the bores
3436a,
3436b when the connector pins are inserted within the bores 3436a, 3436b
(e.g., prevent rotation of greater than 5 degrees).
[00220] FIG. 35A is a perspective view of another example pressure
chamber assembly 3500. FIG. 35B is a perspective partial cutaway view of
the example pressure chamber assembly 3500. FIG. 35C is a perspective
exploded view of the example pressure chamber assembly 3500. In some
embodiments, features of the pressure chamber assembly 3500 can be used
with any of the rotary piston assemblies 200, 700, 1100, 1501, 1701, and
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2700, the rotary piston 3400, and/or with any of the actuators 400, 800, 1200,
1500, 1750, 1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300. As shown in
FIG. 35C, the pressure chamber assembly 3500 includes a piston housing
3550, a modular housing 3510a, and a modular housing 3510b. The modular
housing 3510a includes an arcuate central recess 3512a, and the modular
housing 3510b includes an arcuate central recess 3512b. In their assembled
form, the arcuate central recesses 3512a and 3512b accommodate the piston
housing 3550.
[00221] As shown in FIG. 35C, the piston housing 3550 is formed to
io accommodate a rotary piston 3514 in a cavity 3558. The piston housing
3550
includes a collar 3552. The collar 3552 is formed to hold a seal 3554 in
sealing contact with the rotary piston 3514. In some embodiments, the rotary
piston can be any of the rotary pistons 260, 414, 712, 812, 822,1216, 1520a,
1520b, 1720, 1930, 2222, 2400, 2754, 3350, and 3400. In some
implementations, the pressure chamber 3550 can be formed as a unitary
piston housing. For example, pressure chamber 3550 may be machined,
extruded, hydro formed, or otherwise formed without forming seams within the
pressure chambers 3550.
[00222] The example rotary piston 3514 includes a bore 3556. In some
embodiments, the bore 3356 can be formed with a cross-sectional geometry
that prevents rotation of a connector pin, such as the connector pin 3314 of
FIGs. 33A-33C, within the bore 3556 and the bores (not shown) of a rotor arm,
such as the rotor arms 3312 around the longitudinal axis of the connector pin.
For example, the bore 3356 can be formed to accommodate a "locking pin"
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formed with a square, rectangular, triangular, hex, star, oval, or any other
appropriate non-circular cross-section, such that the connector pin can be
inserted through the bore 3556 and are substantially prevented from rotating
about the axis of the bore 3556 when the connector pin is inserted within the
bore 3556 (e.g., prevent rotation greater than 5 degrees).
[00223] In some embodiments, the rotary piston 3514 can include retainer
elements. For example, the rotary piston 3514 can include the retainer
elements 3380 (for example, as shown in FIGS 33A-C) that can intermesh with
the retainer elements 3382 to prevent rotation of the rotary piston 3550 away
io from the radius of curvature of the rotary pistons 3550.
[00224] FIG. 36 is a perspective view of an example piston housing
assembly 3600. The assembly 3600 includes a piston housing 3650a and a
piston housing 3650b. The piston housings 3650a-3650b each includes a
cavity 3658. In some embodiments, the piston housings 3650a-3650b can be
used in place or in addition to the piston housing 3550 of the example
pressure
chamber assembly 3500 of FIGs. 35A-35C. For example, the piston housings
3650a-3650b can be enclosed by modular housings such as the modular
housings 3510a and 3510b.
[00225] The assembly 3600 includes a collection of fluid ports 3652a and
3652b. The fluid ports 3652a-3652b are in fluid communication with the
cavities 3658 and or fluid supply lines (not shown). In some embodiments, the
fluid ports 3652 can flow fluid among the piston housings 3650a-3650b. For
example, fluid may be applied to pressurize the piston housings 3650a, and
the fluid will flow through the fluid port 3652a to pressurize the piston
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3650b as well. In some embodiments, any appropriate number of piston
housings, such as the piston housings 3650a-3650b, and fluid ports, such as
the fluid ports 3652, can be assembled in an alternating daisy-chain
arrangement to form the assembly 3600.
[00226] FIG. 37 is a schematic of an example rotary piston-type actuator
system 3700. The system 3700 includes the rotary piston-type actuator 400 of
FIG. 4. In some embodiments, the actuator 400 may be replaced in the
system 3700 by any of the rotary piston assemblies 200, 700, 1100, 1501,
1701, 2700, and 3500, the rotary piston 3400, and/or with any of the actuators
800, 1200, 1500, 1750, 1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300.
The system 3700 also includes a controller 3702, and a fluid pressure
assembly 3703. The fluid pressure assembly 3703 includes a servo valve
3704, a fluid pressure source 3706, and a drain 3709.
[00227] In some embodiments, the fluid pressure source 3706 can be a
central fluid pressure source 3706 fluidly connected to the servo valve 3704
by
a high pressure fluid line 3707. In some embodiments, the drain 3709 can be
a central drain or fluid return reservoir fluidly connected to the servo valve
3704 by a low pressure fluid line 3708. For example, the fluid pressure source
3706 can be a fluid pressure pump that provides fluid pressure for multiple
fluid-operated devices, such as the actuator 400. In some embodiments, the
fluid pressure source 3706 can be a central hydraulic or pneumatic pressure
system of an aircraft. In some embodiments, the system 3700 can be used to
actuate a flight control surface or other apparatus in an aircraft.
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[00228] The controller 3702 is fluidly connected to the servo valve 3704 by a
fluid line 3710 and a fluid line 3712. The controller 3702 is configured to
selectively apply fluid pressure to the fluid lines 3710 and 3712 to actuate
the
servo valve 3704. The servo valve 3704 is fluidly connected to the fluid
chambers 422 and the bore 452 by a fluid line 3720, a fluid line 3722, and a
fluid line 3724. The servo valve 3704 is configured to selectively and
reversibly connect the fluid pressure source 3706 and the drain 3708 to the
fluid chambers 422 and the bore 452.
[00229] The system 3700 includes a rotary position sensor assembly 3730.
io The rotary position sensor assembly 3730 is mechanically coupled to the
actuator 400 to provide a signal representative of the position, speed,
direction
of rotation, and/or acceleration of the rotor shaft 412. In some embodiments,
the position sensor assembly 3730 is a position limit sensor configured to
detect when the rotor shaft 412 has moved to a predetermined position. The
signal is provided to the controller 3702 over a conductor 3732, such as a
wire
or an optical fiber. In some embodiments, the controller 3702 can use the
signal from the position sensor assembly 3730 to form a feedback loop for
controlling the position of the rotor shaft 412.
[00230] FIG. 38 is a flow diagram of an example process 3800 for using the
example rotary piston-type actuator system 3700 of FIG. 37. At 3802, a rotary
actuator is provided. The rotary actuator includes a first housing defining a
first arcuate chamber having a first cavity, a first fluid port in fluid
communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and having a rotary output shaft and
a
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first rotor arm extending radially outward from the rotary output shaft, and
an
arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end. A first seal, the
first cavity, and the first piston define a first pressure chamber, and a
first
portion of the first piston contacts the first rotor arm. The actuator also
includes a first fluid line coupled to the first fluid port, a high pressure
fluid line,
and a low pressure fluid line. For example, the rotary piston-type actuator
400
can be provided.
[00231] At 3804 a central pressure source is provided. The central pressure
io source is coupled to the high pressure fluid line. For example, the
fluid
pressure source 3706 is fluidly connected to the servo valve 3704 by the high
pressure fluid line 3707, and the drain 3709 is fluidly connected to the servo
valve 3704 by the low pressure fluid line 3708.
[00232] At 3806, a servo valve is provided. The servo valve is positioned
between the central pressure source and the hydraulic actuator. For example,
the servo valve 3704 is positioned along a fluid path connecting the pressure
source 3706 and the actuator 400.
[00233] At 3808, the servo valve is controlled to selectively connect the
first
fluid line to the high pressure fluid line and the low pressure fluid line.
For
example, the servo valve 3704 can be controlled by the controller 3702 to
selectively connect the fluid lines 3707 and 3708 to the fluid lines 3720,
3722,
and/or 3724.
[00234] At 3810 pressurized fluid is applied to the first pressure chamber.
For example, the servo valve 3704 can be controlled by the controller 3702 to
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adjustably and reversibly apply fluid pressure from the pressure source 3706
to the fluid chamber 422. In some embodiments, the servo valve 3704 can be
controlled to adjustably and reversibly apply fluid pressure from the pressure
source 3706 to the bore 452.
[00235] At 3812, the first piston is urged partially outward from the first
pressure chamber to urge rotation of the rotary output shaft in a first
direction.
For example, fluid pressure in the fluid chambers 422 urges the pistons 414
partially outward from the fluid chambers 422. The outward motion of the
pistons 414 urges rotation of the rotor shaft 412.
[00236] In some embodiments, the housing can include a second arcuate
chamber having a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly further
comprises a second rotor arm. The rotary actuator can also include an
arcuate-shaped second piston positioned in the housing for reciprocal
movement in the second arcuate chamber. A second seal, the second cavity,
and the second piston can define a second pressure chamber, and a first
portion of the second piston can contact the second rotor arm. A second fluid
line can be coupled to the second fluid port, and the servo valve can be
controllable to selectively connect the second fluid line to the high pressure
fluid line and the low pressure fluid line to control movement of the
hydraulic
actuator. In some implementations, the process 3800 can also include
controlling the servo valve to selectively connect the second fluid line to
the
high pressure fluid line and the low pressure fluid line to apply pressurized
fluid
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to the second pressure chamber, and urging the second piston partially
outward from the second pressure chamber.
[00237] In some embodiments, a controller can be coupled to control the
servo valve, and controlling the servo valve can include controlling, by the
controller, the servo valve to selectively connect the first fluid line to the
high
pressure fluid line and the low pressure fluid line to apply pressurized fluid
to
the first pressure chamber. For example, the controller 3702 can control the
servo valve 3704 to connect the pressure source 3706 and the drain 3709 to
the fluid chambers 422 and/or the bore 452.
[00238] In some embodiments, a position sensor (e.g., the position sensor
assembly 3730) can be provided and configured to provide a position feedback
signal indicative of a position of the rotary actuator. A position feedback
signal
from the position sensor can be provided to the controller to control the
servo
valve, and the controller can control the servo valve to selectively connect
the
first fluid line to the high pressure fluid line and the low pressure fluid
line to
apply pressurized fluid to the first pressure chamber based on the position
feedback signal. In some embodiments, the position sensor can be coupled to
the rotary output shaft, and the position feedback signal can be a rotary
position feedback signal. In some embodiments, the position sensor can be a
position limit sensor, and the position feedback signal can be a position
limit
signal. In some implementations, the process 3800 can include urging rotation
of the rotary output shaft to control at least one of the group consisting of
rotary output shaft speed, rotary output shaft position, rotary output shaft
torque, and rotary output shaft acceleration.
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[00239] In some embodiments, the process 3800 can be used with an
actuator having a central actuation assembly, such as the assembly 2900 of
FIGs. 29A-29E or the assembly 3000 of FIGs. 30A-30E.
[00240] FIG. 39 is a schematic of another example rotary piston-type
actuator system. The system 3700 includes the rotary piston-type actuator 400
of FIG. 4. In some embodiments, the actuator 400 may be replaced in the
system 3900 by any of the rotary piston assemblies 200, 700, 1100, 1501,
1701, 2700, and 3500, the rotary piston 3400, and/or with any of the actuators
800, 1200, 1500, 1750, 1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300.
io The system 3900 also includes a controller 3902 and a fluid pressure
source
3906.
[00241] The fluid pressure source 3906 includes a fluid pump 3910 driven by
a motor 3912, which is controlled by the controller 3902. The pump 3910
drives fluid unidirectionally or bidirectionally to and/or from the fluid
chambers
422 and the bore 452 through the fluid lines 3720-3724 to cause actuation of
the rotor shaft 412. A collection of check valves 3914, relief valves 3916,
and
a fluid reservoir 3918 are also interconnected between the fluid lines 3720-
3724 to maintain and protect the integrity of the fluid circuit formed within
the
fluid pressure source 3906.
[00242] In some embodiments, the fluid pressure source 3906 can be a local
fluid pressure source fluidly connected to the assembly 400. For example, the
fluid pressure source 3906 can be a fluid pressure pump that provides fluid
pressure for a single fluid-operated device, such as the actuator 400. In some
embodiments, the fluid pressure source 3906 can be a local (e.g., point of
use)
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hydraulic or pneumatic pressure system of an aircraft. In some embodiments,
the system 3900 can be used to actuate a flight control surface or other
apparatus in an aircraft.
[00243] The system 3900 includes the rotary position sensor assembly 3730.
Signals from the position sensor assembly 3730 are provided to the controller
3902 over a conductor 3732 such as a wire or an optical fiber. In some
embodiments, the controller 3902 can use the signal from the position sensor
assembly 3730 to form a feedback loop for controlling the position of the
rotor
shaft 412.
[00244] FIG. 40 is a flow diagram of an example process 4000 for using the
example rotary piston-type actuator system 3900 of FIG. 39. At 4002, a rotary
actuator is provided. The rotary actuator includes a first housing defining a
first arcuate chamber having a first cavity, a first fluid port in fluid
communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and having a rotary output shaft and
a
first rotor arm extending radially outward from the rotary output shaft, and
an
arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end. A first seal, the
first cavity, and the first piston define a first pressure chamber, and a
first
portion of the first piston contacts the first rotor arm. The actuator also
includes a first fluid line coupled to the first fluid port, a high pressure
fluid line,
and a low pressure fluid line. For example, the rotary piston-type actuator
400
can be provided.
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[00245] At 4004, a fluid reservoir is provided. At 4006, a fluid pump coupled
to the fluid reservoir is provided. For example, the fluid reservoir 3918 and
the
fluid pump 3910 are provided.
[00246] At 4008 the fluid pump is controlled, and at 4010 high pressure is
selectively provided to the first fluid line to apply pressurized fluid to the
first
pressure chamber. For example, the controller 3902 can activate the motor
3912 and drive the fluid pump 3910 to provide high pressure to one or more of
the fluid lines 3720-3724, which in turn provide the pressurized fluid or one
or
more of the fluid chambers 422 and/or the bore 452.
[00247] At 4012, the first piston is urged partially outward from the first
pressure chamber to urge rotation of the rotary output shaft in a first
direction.
For example, fluid pressure in the fluid chambers 422 urges the pistons 414
partially outward from the fluid chambers 422. The outward motion of the
pistons 414 urges rotation of the rotor shaft 412.
[00248] In some embodiments, the housing can include a second arcuate
chamber having a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly further
comprises a second rotor arm. The rotary actuator can also include an
arcuate-shaped second piston positioned in the housing for reciprocal
movement in the second arcuate chamber. A second seal, the second cavity,
and the second piston can define a second pressure chamber, and a first
portion of the second piston can contact the second rotor arm. For example
the assembly 400 includes two of the pistons 414 and two of the fluid
chambers 422. A second fluid line can be coupled to the second fluid port. In
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some implementations, the process 3900 can also include controlling the fluid
pump to selectively provide high pressure to the second fluid line to apply
pressurized fluid to the second pressure chamber, and urging the second
piston partially outward from the second pressure chamber. For example, high
pressure fluid can be applied to a second one of the fluid chambers 422 to
urge a second one of the pistons 414 to move outward. In some
embodiments, the fluid pump can provide high pressure to the bore 452 to
urge the pistons 414 into the fluid chambers 422.
[00249] In some embodiments, a controller can be coupled to control the
fluid pump, and controlling the fluid pump can include controlling, by the
controller, the fluid pump to selectively apply pressurized fluid to the first
pressure chamber. For example, the controller 3902 can control the motor
3912 to selectively pressurize the fluid chambers 422 and/or the bore 452.
[00250] In some embodiments, a position sensor (e.g., the position sensor
assembly 3730) can be provided and configured to provide a position feedback
signal indicative of a position of the rotary actuator. A position feedback
signal
from the position sensor can be provided to the controller to control the
servo
valve, and the controller can control the servo valve to selectively connect
the
first fluid line to the high pressure fluid line and the low pressure fluid
line to
apply pressurized fluid to the first pressure chamber based on the position
feedback signal. In some embodiments, the position sensor can be coupled to
the rotary output shaft, and the position feedback signal can be a rotary
position feedback signal. In some embodiments, the position sensor can be a
position limit sensor, and the position feedback signal can be a position
limit
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signal. In some implementations, the process 3900 can include urging rotation
of the rotary output shaft to control at least one of the group consisting of
rotary output shaft speed, rotary output shaft position, rotary output shaft
torque, and rotary output shaft acceleration.
[00251] In some embodiments, the process 3900 can be used with an
actuator having a central actuation assembly, such as the assembly 2900 of
FIGs. 29A-29E or the assembly 3000 of FIGs. 30A-30E, which may be the
central actuation assembly of an aircraft.
[00252] FIG. 41 is a schematic of another example rotary piston-type
io actuator system 4100. The system 4100 includes the rotary piston-type
actuator 400 of FIG. 4. In some embodiments, the actuator 400 may be
replaced in the system 4100 by any of the rotary piston assemblies 200, 700,
1100, 1501, 1701, 2700, and 3500, the rotary piston 3400, and/or with any of
the actuators 800, 1200, 1500, 1750, 1900, 2200, 2300, 2600, 2900, 3000,
3200 and 3300. The system 4100 also includes a controller 4102, the fluid
pressure assembly 3703, the fluid pressure source 3906, and a mode select
valve 4104.
[00253] The fluid pressure assembly 3703 and the fluid pressure source
3906 are each controllably connected to the controller 4102. The mode select
valve 4104 is controllably linked to the controller 4102, and the controller
4102
is configured to actuate the mode select valve 4104 to selectably and fluidly
connect the fluid pressure assembly 3703 and the fluid pressure source 3906
to the fluid lines 3720-3724. The controller 4102 controls the mode select
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valve 4104 and the selected one of the fluid pressure assembly 3703 and the
fluid pressure source 3906 to actuate the actuator 400.
[00254] In some embodiments, the system 4100 can be used to provide
redundant control of an actuator. For example, the actuator 400 can be
operated using fluid pressure provided by the fluid pressure assembly 3703
(e.g., a central hydraulic pressure system in an aircraft), but in the event
of a
malfunction in the fluid pressure assembly 3703 the controller 4102 can
actuate the mode select valve 4104 to cause the actuator 400 to be operated
using fluid pressure provided by the fluid pressure source 3906 (e.g., a local
io hydraulic pressure system located near the actuator 400 in an aircraft).
[00255] The system 4100 includes the rotary position sensor assembly 3730.
Signals from the position sensor assembly 3730 are provided to the controller
3902 over the conductor 3732 such as a wire or an optical fiber. In some
embodiments, the controller 4102 can use the signal from the position sensor
assembly 3730 to form a feedback loop for controlling the position of the
rotor
shaft 412. In some embodiments, the system 4100 can be used to actuate a
flight control surface or other apparatus in an aircraft.
[00256] FIG. 42 is a flow diagram of an example process 4200 for using the
example rotary piston-type actuator system 4100 of FIG. 41. At 4202, a rotary
actuator is provided. The rotary actuator includes a first housing defining a
first arcuate chamber having a first cavity, a first fluid port in fluid
communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and having a rotary output shaft and
a
first rotor arm extending radially outward from the rotary output shaft, and
an
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arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end. A first seal, the
first cavity, and the first piston define a first pressure chamber, and a
first
portion of the first piston contacts the first rotor arm. The actuator also
includes a first fluid line coupled to the first fluid port, a high pressure
fluid line,
and a low pressure fluid line. For example, the rotary piston-type actuator
400
can be provided.
[00257] At 4204 a central pressure source is provided. The central pressure
source is coupled to the high pressure fluid line. For example, the fluid
io pressure source 3706 is fluidly connected to the servo valve 3704 by the
high
pressure fluid line 3707, and the drain 3709 is fluidly connected to the servo
valve 3704 by the low pressure fluid line 3708.
[00258] At 4206, a servo valve is provided. The servo valve is positioned
between the central pressure source and the hydraulic actuator. For example,
the servo valve 3704 is positioned along a fluid path connecting the pressure
source 3706 to the mode select valve 4104 and the actuator 400.
[00259] At 4208 a fluid reservoir is provided. At 4210, a fluid pump coupled
to the fluid reservoir is provided. For example, the fluid reservoir 3918 and
the
fluid pump 3910 are provided. At 4212, a valve block is provided. For
example, the mode select valve 4104 is provided in the system 4100.
[00260] At 4214 the fluid pump, the servo valve, and the valve block are
controlled, and at 4216 high pressure is selectively provided to the first
fluid
line to apply pressurized fluid to the first pressure chamber. For example,
the
controller 4102 can activate the motor 3912, the servo valve 3704, and the
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mode select valve 4104 to connect and provide high pressure to one or more
of the fluid lines 3720-3724, which in turn provide the pressurized fluid or
one
or more of the fluid chambers 422 and/or the bore 452.
[00261] At 4218, the first piston is urged partially outward from the first
pressure chamber to urge rotation of the rotary output shaft in a first
direction.
For example, fluid pressure in the fluid chambers 422 urges the pistons 414
partially outward from the fluid chambers 422. The outward motion of the
pistons 414 urges rotation of the rotor shaft 412.
[00262] In some embodiments, the housing can include a second arcuate
io chamber having a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly further
comprises a second rotor arm. The rotary actuator can also include an
arcuate-shaped second piston positioned in the housing for reciprocal
movement in the second arcuate chamber. A second seal, the second cavity,
and the second piston can define a second pressure chamber, and a first
portion of the second piston can contact the second rotor arm. For example
the assembly 400 includes two of the pistons 414 and two of the fluid
chambers 422. A second fluid line can be coupled to the second fluid port. In
some implementations, the process 4200 can also include controlling the fluid
pump to selectively provide high pressure to the second fluid line to apply
pressurized fluid to the second pressure chamber, and urging the second
piston partially outward from the second pressure chamber. For example, high
pressure fluid can be applied to a second one of the fluid chambers 422 to
urge a second one of the pistons 414 to move outward. In some
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embodiments, the fluid pump can provide high pressure to the bore 452 to
urge the pistons 414 into the fluid chambers 422.
[00263] In some embodiments, a controller can be coupled to control the
fluid pump. In some embodiments, controlling the servo valve can include
controlling, by the controller, the servo valve to selectively connect the
first
fluid line to the high pressure fluid line and the low pressure fluid line to
apply
pressurized fluid to the first pressure chamber. In some embodiments,
controlling the fluid pump can include controlling, by the controller, the
fluid
pump to selectively apply pressurized fluid to the first pressure chamber. In
io some embodiments, controlling the valve block can include controlling,
by the
controller, the valve block to selectively connect the servo valve and the
fluid
pump to the first pressure chamber. For example, the controller 4102 can
control the motor 3912, the servo valve 3704, and the mode select valve 4104
to selectively pressurize the fluid chambers 422 and/or the bore 452.
[00264] In some embodiments, a position sensor (e.g., the position sensor
assembly 3730) can be provided and configured to provide a position feedback
signal indicative of a position of the rotary actuator. A position feedback
signal
from the position sensor can be provided to the controller to control the
servo
valve, and the controller can control the servo valve to selectively connect
the
first fluid line to the high pressure fluid line and the low pressure fluid
line to
apply pressurized fluid to the first pressure chamber based on the position
feedback signal. In some embodiments, the position sensor can be coupled to
the rotary output shaft, and the position feedback signal can be a rotary
position feedback signal. In some embodiments, the position sensor can be a
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position limit sensor, and the position feedback signal can be a position
limit
signal. In some implementations, the process 4200 can include urging rotation
of the rotary output shaft to control at least one of the group consisting of
rotary output shaft speed, rotary output shaft position, rotary output shaft
torque, and rotary output shaft acceleration.
[00265] In some embodiments, the process 4200 can be used with an
actuator having a central actuation assembly, such as the assembly 2900 of
FIGs. 29A-29E or the assembly 3000 of FIGs. 30A-30E.
[00266] FIG. 43 is a schematic of another example rotary piston-type
io actuator system 4300. The system 4300 includes the rotary piston-type
actuator 2900 of FIGs. 29A-29E. In some embodiments, the actuator 2900
may be replaced in the system 4300 by any appropriate one or combination of
the rotary piston assemblies 200, 700, 1100, 1501, 1701, 2700, and 3500, the
rotary piston 3400, and/or with any of the actuators 800, 1200, 1500, 1750,
1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300. The system 4300 also
includes a controller 4302, the fluid pressure assembly 3703, and the fluid
pressure source 3906.
[00267] The fluid pressure assembly 3703 and the fluid pressure source
3906 are each controllably connected to the controller 4302. The fluid
pressure assembly 3703 is fluidly connected by a fluid line 4310 and a fluid
line 4312 to one or more fluid chambers, e.g., the pressure chambers 1252a of
FIGs. 12-14, formed as arcuate cavities in the first pressure chamber
assembly 2950a. The fluid pressure source 3906 is fluidly connected by a fluid
line 4314 and a fluid line 4316 to one or more fluid chambers, e.g., the
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pressure chambers 1252a of FIGs. 12-14, formed as arcuate cavities in the
second pressure chamber assembly 2950b.
[00268] In some embodiments, the system 4300 can be used to provide
redundant control of an actuator. For example, the actuator 2900 can be
operated using fluid pressure provided by the fluid pressure assembly 3703
(e.g., a central hydraulic pressure system in an aircraft) and the fluid
pressure
source 3906 (e.g., a local hydraulic pressure system in an aircraft). In some
embodiments, the fluid pressure assembly 3703 and the pressure source 3906
can be operated substantially simultaneously by the controller 4302. In some
embodiments, the fluid pressure assembly 3703 and the pressure source 3906
can be operated alternatingly by the controller 4302. For example, the
actuator 2900 can be operated under fluid pressure provided by the pressure
source 3703, and when a malfunction is detected in the pressure source 3703,
the controller 4302 can control the pressure source 3906 to control the
actuator 2900 in a redundant backup configuration. In some embodiments, the
system 4300 can be used to actuate a flight control surface or other apparatus
in an aircraft.
[00269] The system 4300 includes the rotary position sensor assembly 3730.
Signals from the position sensor assembly 3730 are provided to the controller
4302 over a conductor 4332 such as a wire or an optical fiber. In some
embodiments, the controller 4302 can use the signal from the position sensor
assembly 3730 to form a feedback loop for controlling the position of the
rotor
shaft 412.
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[00270] FIG. 44 is a flow diagram of an example process 4400 for using the
example rotary piston-type actuator system of FIG. 43. At 4402, a rotary
actuator is provided. The rotary actuator includes a first housing defining a
first arcuate chamber having a first cavity, a first fluid port in fluid
communication with the first cavity, and an open end, a rotor assembly
rotatably journaled in said first housing and having a rotary output shaft and
a
first rotor arm extending radially outward from the rotary output shaft, and
an
arcuate-shaped first piston disposed in said first housing for reciprocal
movement in the first arcuate chamber through the open end. A first seal, the
io first cavity, and the first piston define a first pressure chamber, and
a first
portion of the first piston contacts the first rotor arm. The actuator also
includes a first fluid line coupled to the first fluid port, a high pressure
fluid line,
and a low pressure fluid line. For example, the rotary piston-type actuator
2900 can be provided.
[00271] At 4404 a central pressure source is provided. The central pressure
source is coupled to the high pressure fluid line. For example, the fluid
pressure source 3706 is fluidly connected to the servo valve 3704 by the high
pressure fluid line 3707, and the drain 3709 is fluidly connected to the servo
valve 3704 by the low pressure fluid line 3708.
[00272] At 4406, a servo valve is provided. The servo valve is positioned
between the central pressure source and the hydraulic actuator. For example,
the servo valve 3704 is positioned along a fluid path connecting the pressure
source 3706 to the mode select valve 4104 and the actuator 2900.
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[00273] At 4408 a fluid reservoir is provided. At 4410, a fluid pump coupled
to the fluid reservoir is provided. For example, the fluid reservoir 3918 and
the
fluid pump 3910 are provided.
[00274] At 4412 the servo valve is controlled, and at 4414 pressurized fluid
is applied to the first fluid line to provide pressurized fluid to the first
pressure
chamber. For example, the controller 4402 can control the servo valve 3704 to
provide high pressure fluid to one or more of the fluid lines 4310-4312, which
in turn provide the pressurized fluid or one or more of the fluid chambers in
the
first pressure chamber assembly 2950a.
[00275] At 4416, the first piston is urged partially outward from the first
pressure chamber to urge rotation of the rotary output shaft in a first
direction.
For example, fluid pressure in the fluid chambers in the first pressure
chamber
assembly 2950a urges pistons, e.g., the dual rotary pistons 1216 of FIGs. 12-
14, partially outward from the fluid chambers. The outward motion of the
pistons urges rotation of the rotor shaft 2912.
[00276] At 4418 the fluid pump is controlled, and at 4420 pressurized fluid is
applied to the second fluid line to provide pressurized fluid to the second
pressure chamber. For example, the controller 4402 can control the fluid
pump 3910 to provide high pressure fluid to one or more of the fluid lines
4314-4316, which in turn provide the pressurized fluid or one or more of the
fluid chambers in the second pressure chamber assembly 2950b.
[00277] At 4422, the second piston is urged partially outward from the
second pressure chamber to urge rotation of the rotary output shaft in a first
direction. For example, fluid pressure in the fluid chambers in the second
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pressure chamber assembly 2950b urges pistons, e.g., the dual rotary pistons
1216 of FIGs. 12-14, partially outward from the fluid chambers. The outward
motion of the pistons urges rotation of the rotor shaft 2912. In some
embodiments, the second piston is urged partially outward from the second
pressure chamber to urge rotation of the rotary output shaft in a second
direction.
[00278] In some embodiments, a central actuation assembly can be
provided, including a central mounting point formed in an external surface of
the rotary output shaft, where the central mounting point is proximal to the
io longitudinal midpoint of the rotary output shaft. In some embodiments,
an
actuation arm can be removably attached at a proximal end to the central
mounting point, the actuation arm adapted at a distal end for attachment to an
external mounting feature of a member to be actuated. In some embodiments,
the process 4400 can include urging rotation of the actuation arm, and
urging motion of the member to be actuated. For example, the rotary piston-
type actuator 2900 includes the central actuation assembly 2960 and the
central mounting assembly 2980.
[00279] In some embodiments, the housing can include a second arcuate
chamber having a second cavity, and a second fluid port in fluid
communication with the second cavity, wherein the rotor assembly further
comprises a second rotor arm. The rotary actuator can also include an
arcuate-shaped second piston positioned in the housing for reciprocal
movement in the second arcuate chamber. A second seal, the second cavity,
and the second piston can define a second pressure chamber, and a first
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portion of the second piston can contact the second rotor arm. For example
the assembly 2900 can include one or more of the dual rotary pistons 1216 of
FIGs. 12-14, and two fluid chambers, e.g., the pressure chambers 1252a of
FIGs. 12-14, formed as arcuate cavities in the first pressure chamber
assembly 2950a. A second fluid line can be coupled to the second fluid port.
In some implementations, the process 4400 can also include controlling the
fluid pump to selectively provide high pressure to the second fluid line to
apply
pressurized fluid to the second pressure chamber, and urging the second
piston partially outward from the second pressure chamber. For example, high
io pressure fluid can be applied to a second one of the fluid chambers in
the first
pressure chamber assembly 2950a to urge a second one of the pistons to
move outward.
[00280] In some embodiments, the fluid pump may not be connected to a
central hydraulic system. For example, the fluid pump 3910 is connected to
the fluid reservoir 3918 and not the fluid pressure source 3706.
[00281] In some embodiments, a first controller can be coupled to control the
servo valve, and a second controller can be coupled to control the fluid pump.
In some embodiments, the first controller and the second controller can be a
single controller. For example, the controller 4202 is configured to control
both
the servo valve 3704 and the fluid pump 3910. In some embodiments,
controlling the servo valve can include controlling, by the controller, the
servo
valve to selectively connect the first fluid line to the high pressure fluid
line and
the low pressure fluid line to apply pressurized fluid to the first pressure
chamber. In some embodiments, controlling the fluid pump can include
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controlling, by the controller, the fluid pump to selectively apply
pressurized
fluid to the second pressure chamber. For example, the controller 4402 can
control the motor 3912 and the servo valve 3704 to selectively pressurize the
fluid chambers in the first pressure chamber assembly 2950a and the second
pressure chamber assembly 2950b.
[00282] In some embodiments, a position sensor (e.g., the position sensor
assembly 3730) can be provided and configured to provide a position feedback
signal indicative of a position of the rotary actuator. A position feedback
signal
from the position sensor can be provided to the first controller to control
the
io servo valve and to the second controller to control the fluid pump, and
the
controllers can control the servo valve and the fluid pump based on the
position feedback signal. In some embodiments, the position sensor can be
coupled to the rotary output shaft, and the position feedback signal can be a
rotary position feedback signal. In some embodiments, the first controller,
the
servo, and the position sensor can be configured as a first feedback loop, and
the second controller, the fluid pump, and the position sensor can be
configured as a second feedback loop.
[00283] In some embodiments, the position sensor can be a position limit
sensor, and the position feedback signal can be a position limit signal. In
some implementations, the process 4400 can include urging rotation of the
rotary output shaft to control at least one of the group consisting of rotary
output shaft speed, rotary output shaft position, rotary output shaft torque,
and
rotary output shaft acceleration.
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[00284] In some embodiments, the first seal can be disposed about an
interior surface of the open end. For example, the first seal can be the seal
1560 of FIG. 16, which is disposed about the interior surface at the open end
1565. In some embodiments, the first seal can be disposed about the
periphery of the first piston. In some embodiments, the first housing can be
formed as a one-piece housing. For example, the pressure chambers 1252a
of FIGs. 12-14 are formed as one-piece chambers. In some embodiments, the
first seal can be a one-piece seal. In some embodiments, first rotor arm can
be coupled to a flight control surface of an aircraft. In some embodiments,
the
io first rotor arm can be coupled to a primary flight control surface of an
aircraft.
In some embodiments, the central pressure source can be a central hydraulic
system of an aircraft.
[00285] FIG. 45 is a schematic of another example rotary piston-type
actuator system 4500. The system 4500 includes the rotary piston-type
actuator 2900 of FIGs. 29A-29E. In some embodiments, the actuator 2900
may be replaced in the system 4500 by any appropriate one or combination of
the rotary piston assemblies 200, 700, 1100, 1501, 1701, 2700, and 3500, the
rotary piston 3400, and/or with any of the actuators 800, 1200, 1500, 1750,
1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300. The system 4500 also
includes a controller 4502, the fluid pressure assembly 3703, and a fluid
pressure source 4503.
[00286] The fluid pressure assembly 3703 is fluidly connected by the fluid
lines 4310-4312 to one or more fluid chambers, e.g., the pressure chambers
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1252a of FIGs. 12-14, formed as arcuate cavities in the first pressure chamber
assembly 2950a.
[00287] The fluid pressure source 4503 includes a fluid pump 4510 driven by
the motor 3912, which is controlled by the controller 4502. The fluid pump
4510 drives pressurized fluid unidirectionally to a servo valve 4504, and the
controller 4502 controls the servo valve 4504 to selectably provide the
pressurized fluid to the fluid chambers of the second pressure chamber
assembly 2950b through the fluid lines 4314-4316 to cause actuation of the
rotor shaft 2912.
[00288] In some embodiments, the system 4500 can be used to provide
redundant control of an actuator. For example, the actuator 2900 can be
operated using fluid pressure provided by the fluid pressure assembly 3703
(e.g., a central hydraulic pressure system in an aircraft) and the fluid
pressure
source 4503 (e.g., a local hydraulic pressure system in an aircraft). In some
embodiments, the fluid pressure assembly 3703 and the pressure source 4503
can be operated substantially simultaneously by the controller 4502. In some
embodiments, the fluid pressure assembly 3703 and the pressure source 3503
can be operated alternatingly by the controller 4502. For example, the
actuator 2900 can be operated under fluid pressure provided by the pressure
source 3703, and when a malfunction is detected in the pressure source 3703,
the controller 4502 can control the pressure source 4503 to control the
actuator 2900 in a redundant backup configuration. In some embodiments, the
system 4500 can be used to actuate a flight control surface or other apparatus
in an aircraft.
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[00289] The system 4500 includes the rotary position sensor assembly 3730.
Signals from the position sensor assembly 3730 are provided to the controller
4502 over the conductor 4332. In some embodiments, the controller 4502 can
use the signal from the position sensor assembly 3730 to form a feedback loop
for controlling the position of the rotor shaft 2912.
[00290] FIG. 46 is a schematic of another example rotary piston-type
actuator system 4600. The system 4600 includes the rotary piston-type
actuator 2900 of FIGs. 29A-29E. In some embodiments, the actuator 2900
may be replaced in the system 4500 by any appropriate one or combination of
io the rotary piston assemblies 200, 700, 1100, 1501, 1701, 2700, and 3500,
the
rotary piston 3400, and/or with any of the actuators 800, 1200, 1500, 1750,
1900, 2200, 2300, 2600, 2900, 3000, 3200 and 3300. The system 4600 also
includes a controller 4602 and two of the fluid pressure sources 3703.
[00291] One of the fluid pressure sources 3703 is fluidly connected by the
fluid lines 4310-4312 to one or more fluid chambers, e.g., the pressure
chambers 1252a of FIGs. 12-14, formed as arcuate cavities in the first
pressure chamber assembly 2950a.
[00292] The other of the fluid pressure sources 3703 is fluidly connected by
the fluid lines 4314-4316 to one or more fluid chambers, e.g., the pressure
chambers 1252a of FIGs. 12-14, formed as arcuate cavities in the first
pressure chamber assembly 2950b.
[00293] In some embodiments, the system 4600 can be used to provide
redundant control of an actuator. For example, the actuator 2900 can be
operated using fluid pressure provided by both of the fluid pressure sources
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3703. In some embodiments, the fluid pressure sources 3703 can be operated
substantially simultaneously by the controller 4602. In some embodiments, the
fluid pressure sources 3703 can be operated alternatingly by the controller
4602. For example, the actuator 2900 can be operated under fluid pressure
provided by a first one of the pressure sources 3703, and when a malfunction
is detected in the first pressure source 3703, the controller 4602 can control
the a second one of the pressure sources 3703 to control the actuator 2900 in
a redundant backup configuration.
[00294] In some embodiments, any appropriate combination of two or more
fluid pressure sources can be used to control the actuator 2900. For example,
two of the fluid pressure sources 4503 of FIG. 45 can be used, or two of the
fluid pressure sources 3906 can be used, or any appropriate combination of
the pressure sources 3703, 3906, and 4503 can be used simultaneously or
alternatingly in a redundant backup configuration for the system 4600. In
some embodiments, the system 4600 can be used to actuate a flight control
surface or other apparatus in an aircraft.
[00295] The system 4600 includes the rotary position sensor assembly 3730.
Signals from the position sensor assembly 3730 are provided to the controller
4602 over the conductor 4332. In some embodiments, the controller 4602 can
use the signal from the position sensor assembly 3730 to form a feedback loop
for controlling the position of the rotor shaft 2912.
[00296] FIG. 47 is a schematic of another example rotary piston-type
actuator system 4700. The system 4700 includes the rotary piston-type
actuator 400 of FIGs. 29A-29E. In some embodiments, the actuator 400 may
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be replaced in the system 4700 by any of the rotary piston assemblies 200,
700, 1100, 1501, 1701, 2700, and 3500, the rotary piston 3400, and/or with
any of the actuators 800, 1200, 1500, 1750, 1900, 2200, 2300, 2600, 2900,
3000, 3200 and 3300. The system 4700 also includes a controller 4702, the
fluid pressure source 3706, the drain 3704, the motor 3912, the fluid pump
4510, the reservoir 3918, the mode select valve 4104, and the servo valve
3704.
[00297] The mode select valve 4104 is controllable by the controller 4702 to
selectably provide fluid pressure from the fluid pressure source 3706 and the
fluid pump 4510 to the servo valve 3704. The servo valve 3704 is fluidly
connected to the fluid chambers 422 and the bore 452 by the fluid line 3720,
the fluid line 3722, and the fluid line 3724. The controller 4702 is fluidly
connected to the servo valve 3704 by a fluid line 4710 and a fluid line 4712.
The controller 4702 is configured to selectively apply fluid pressure to the
fluid
lines 3710 and 3712 to actuate the servo valve 3704. The servo valve 3704 is
configured to selectively and reversibly connect the fluid pressure provided
through the mode select valve 4104 to the fluid chambers 422 and the bore
452.
[00298] The system 4700 includes the rotary position sensor assembly 3730.
The rotary position sensor assembly 3730 is mechanically coupled to the
actuator 400 to provide a signal representative of the position, speed, and/or
acceleration of the rotor shaft 412. In some embodiments, the position sensor
assembly 3730 is a position limit sensor configured to detect when the rotor
shaft 412 has moved to a predetermined position. The signal is provided to
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the controller 4702 over the conductor 3732. In some embodiments, the
controller 4702 can use the signal from the position sensor assembly 3730 to
form a feedback loop for controlling the position of the rotor shaft 412.
[00299] In some embodiments, the system 4700 can be used to provide
redundant control of an actuator. For example, the actuator 400 can be
operated using fluid pressure provided by both of the fluid pressure source
3706 and the fluid pump 4510. For example, the actuator 400 can be operated
under fluid pressure provided by the fluid pressure source 3706, and when a
malfunction is detected in the pressure source 3706, the controller 4702 can
io control the mode select valve 4104 to select the fluid pump 4510 to
provide
fluid pressure to actuate the actuator 400 in a redundant backup
configuration.
In some embodiments, the system 4700 can be used to actuate a flight control
surface or other apparatus in an aircraft.
[00300] In some embodiments, any appropriate combination of two or more
fluid pressure sources can be used to control the actuator 400. For example,
two of the fluid pressure sources 4503 of FIG. 45 can be used, or two of the
fluid pressure sources 3906 can be used, or any appropriate combination of
the pressure sources 3703, 3906, and 4503 can be used simultaneously or
alternatingly in a redundant backup configuration for the system 4600.
[00301] FIG. 48 is a schematic of another example rotary piston-type
actuator system 4800. The system 4800 includes the rotary piston-type
actuator 400 of FIGs. 29A-29E. In some embodiments, the actuator 400 may
be replaced in the system 4800 by any of the rotary piston assemblies 200,
700, 1100, 1501, 1701, 2700, and 3500, the rotary piston 3400, and/or with
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any of the actuators 800, 1200, 1500, 1750, 1900, 2200, 2300, 2600, 2900,
3000, 3200 and 3300. The system 4800 also includes a controller 4802, the
fluid pressure assembly 3703, the fluid pressure source 4503, and the mode
select valve 4104.
[00302] The mode select valve 3704 is fluidly connected to the fluid
chambers 422 and the bore 452 by the fluid line 3720, the fluid line 3722, and
the fluid line 3724. The mode select valve 4104 is controllable by the
controller 4802 to selectably provide fluid pressure from the fluid pressure
assembly 3703 and the fluid pressure source 4503 to the fluid chamber 422
io and the bore 452. The controller 4702 is configured to selectively
control the
fluid pressure sources 3703, 3906 and the mode select valve 4104 to
selectively and reversibly connect the fluid pressure provided through the
mode select valve 4104 to the fluid chambers 422 and the bore 452 to actuate
the actuator 400
[00303] The system 4800 includes the rotary position sensor assembly 3730.
The rotary position sensor assembly 3730 is mechanically coupled to the
actuator 400 to provide a signal representative of the position, speed, and/or
acceleration of the rotor shaft 412. In some embodiments, the position sensor
assembly 3730 is a position limit sensor configured to detect when the rotor
shaft 412 has moved to a predetermined position. The signal is provided to
the controller 4802 over the conductor 3732. In some embodiments, the
controller 4802 can use the signal from the position sensor assembly 3730 to
form a feedback loop for controlling the position of the rotor shaft 412.
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[00304] In some embodiments, the system 4800 can be used to provide
redundant control of an actuator. For example, the actuator 400 can be
operated using fluid pressure provided by both of the fluid pressure assembly
3703 and the fluid pressure source 3906. For example, the actuator 400 can
be operated under fluid pressure provided by the fluid pressure assembly
3703, and when a malfunction is detected in the pressure source 3703, the
controller 4802 can control the mode select valve 4104 to select the fluid
pump
3910 to provide fluid pressure to actuate the actuator 400 in a redundant
backup configuration. In some embodiments, the system 4800 can be used to
io actuate a flight control surface or other apparatus in an aircraft.
[00305] In some embodiments, any appropriate combination of two or more
fluid pressure sources can be used to control the actuator 400. For example,
two of the fluid pressure sources 4503 of FIG. 45 can be used, or two of the
fluid pressure sources 3906 can be used, or any appropriate combination of
the pressure sources 3703, 3906, and 4503 can be used simultaneously or
alternatingly in a redundant backup configuration for the system 4800.
[00306] Although a few implementations have been described in detail
above, other modifications are possible. For example, the logic flows depicted
in the figures do not require the particular order shown, or sequential order,
to
achieve desirable results. In some examples, the terms "about", "proximal",
"approximately", "substantially", or other such terms in association with a
position or quantity, can mean but are not limited to, the described position
or
quantity plus or minus 10% of the described quantity or length of the major
dimension of the described position, or within 10% deviation from of the
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average of the described quantity or position, unless specified otherwise. In
addition, other steps may be provided, or steps may be eliminated, from the
described flows, and other components may be added to, or removed from,
the described systems. Accordingly, other implementations are within the
scope of the following claims.
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