Note: Descriptions are shown in the official language in which they were submitted.
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CONTINUOUSLY VARIABLE TRANSMISSION
TTTTT,T~TN V R T F VI OUS COUPLING
" PRIOR ART
A patent search was not conducted on this invention.
The applicant herein has obtained a United States Patent
No. 5,030,180, issued July 9, 1991, entitled "VARIABLE
TRANSMISSION APPARATUS" and a second United States Patent
No. 5,299,985, issued April 5,1994, entitled
"CONTINUOUSLY VARIABLE TRANSMISSION APPARATUS".
PR~'FERRED EMBODIMENT OF TH NVENTT
In one preferred embodiment of this invention, a
continuously variable transmission utilizing variable
viscous couplings, hereinafter referred to as
continuously variable transmission, utilizes power
planetary gear sets in combination with viscous clutch or
coupling means utilized with a common ring gear means.
As noted in Fig. l, the continuously variable
transmission includes 1) a power input means; 2) a common
ring gear means connected to the power input means; 3) a
center planetary and reverse clutch means connected to
the power input means and the common ring gear means; and
4) a power output means operably connected to the common
ring gear means and the center planetary and reverse
clutch means.
The power input means includes a power input shaft
rotatably driven by a power source such as an internal
combustion engine and having an inner end connected to a
planetary input assembly. The power input shaft is
Y
rotatably mounted on an input shaft bearing member.
The planetary input assembly includes an input sun
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gear member connected to and rotated by the power input
shaft and input planet gear members operably engagable
with the input sun gear member and the common ring gear
means.
The input sun gear member includes a sun gear '
support body having outer sun gear teeth members which
are engagable-with the input planet gear members in a
known conventional manner in the use of power planetary
gear sets_
Each of the input planet gear members includes a
central bearing member connected to a planet gear support
body having planet gear teeth members on an outer
periphery thereof which are engagable with the ring gear
teeth members on the common ring gear means.
The common ring gear means includes 1) a common ring
gear member operably engagable with all of three power
plant gear sets as will be noted; 2)a start variable
viscous clutch or coupling which is engagable with the
common ring gear member; and 3) a ratio variable viscous
clutch or coupling which is engagable with the common
ring gear members_
The common ring gear member is provided with three
spaced sets of interior ring gear teeth members which are
engagable with spaced respective ones of three power
planetary gearsets.
The start variable viscous clutch is provided with
1) outer fixed clutch plates which are secured to a
transmission housing; 2) inner rotatable clutch plates
which are connected to the common ring gear member; and
3) a clutch actuator piston member which is operable with
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viscous fluid to lock the inner fixed clutch plates and
inner rotatable clutch plates to selectively cease
rotation of the common ring gear member..
The ratio variable viscous clutch is provided with
' 1) outer movable clutch plates connected to the common
ring gear member; 2) inner movable clutch plates which
are connected to a portion of the power output means; and
3) a ratio clutch actuator piston member which acts
variably with viscous fluid to selectively transfer power
from the common ring gear member to the power output
means.
The center planetary and reverse clutch means
includes 1) a center planetary gear assembly operably
connected to a portion of the input planetary assembly of
the power input means; and 2) a reverse variable viscous
clutch or coupling which is connected by an input carrier
member to the center planetary gear assembly.
The center planetary gear assembly includes 1) a
center hollow sun gear assembly; and 2) a center planet
gear assembly operably connected to the center hollow sun
gear assembly. The center hollow sun gear-assembly
includes a sun gear support body connected to a center
sun gear member.
The center sun gear member has outer center sun gear
teeth members thereon which are engagable with the center
planet gear assembly in a known manner during use of
power planetary gear sets.
The center planet gear assembly includes center
' planet gear members having outer center planet gear teeth
members engagable with the center sun gear member and the
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common ring gear member.
The reverse variable viscous clutch includes 1)
reverse movable clutch plates connected to the input
carrier member; 2) reverse fixed clutch plates connected
to an adjacent portion of the transmi:~sion housing; and "
3) a reverse clutch actuator piston member operable in a
known viscous fluid coupling to permit or cease rotation
of the reverse movable clutch plates.
The power output means includes 1) a center carrier
member supported in bearing members in respective ones of
the center planet gear members; 2) a control planetary
gear assembly engagable with a portion. of the common ring
gear member and connected to the center carrier member;
and 3) a power output shaft mounted in a bearing member
and connected to the control planetary gear assembly.
The control planetary gear assembly includes a
control sun gear assembly operably connected to a control
planetary gear assembly.
The control sun gear assembly includes a control sun
gear member connected to the center carrier member by a
sun gear shaft member and to the power output shaft
member. The control sun gear member includes a control
sun gear body member connected to outer peripheral
control sun gear teeth members engagable with the control
planetary gear assembly in a known manner during
operation of a power planetary gear set.
The control planetary gear assembly includes three ,
('3) equally spaced control planetary gear members with
each having a central bearing member. Each control "
planetary gear member has a support body member with
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peripheral control gear teeth members which are engagable
with the control sun gear teeth members during
conventional operation of a power planetary gear set.
A second embodiment is noted in Fig. 2 and presents
a heavy duty continuously variable transmission wherein
the control planetary gear assembly of the first
embodiment is replaced by an output planetary gear
assembly.
The output planetary gear assembly includes 1) an
output sun gear member; 2) a plurality of output planet
gear members operably connected to the output sun gear
member; and 3) an output carrier member. The output
carrier member has one end mounted in the bearing members
in respective ones of the output planet gear members and
opposite ends connected to inner movable clutch plates of
the ratio variable viscous clutch.
The power output means includes the power output
shaft which is connected by a transverse support shaft or
plate member connected to the output carrier member and
not directly connected to the control sun gear body
member as presented in the embodiment of Fig. 1.
One object of this invention is to provide a
continuously variable transmission achieving a continuous
power transmission output utilizing a plurality of
variable viscous couplings in combination with a
z plurality of power planetary gear sets to achieve a
continuously variable power output.
' Another object of this invention is to provide a
continuously variable transmission means utilizing an
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elongated common ring gear means which is connected
through variable viscous clutch couplings to respective
units of power planetary gear sets to achieve a ,
continuously variable power output.
One other object of this invention is to provide a '
continuously variable transmission utilizing 1) a reverse
viscous clutch connected to a power input means; 2) a
start variable viscous clutch engagable with a common
ring gear member; and 3) a ratio variable viscous clutch
engagable with a power output means to achieve a fuel
saving, efficient and effective continuously variable
power output .
A further object of this invention is to provide a
continuously variable transmission utilizing a start
variable viscous clutchor coupling means used to control
rotation of a common ring gear means in a low range
operation; a ratio variable viscous clutch or coupling
means used to control operation of a control planetary
gear assembly to achieve a continuous7_y variable power
output; and a reverse variable viscous clutch or coupling
means used to control operation of a r_entral planetary
gear assembly to achieve a reverse rotation.
One further object of this invention is to provide a
second embodiment of a continuously variable transmission
for heavy duty truck use having three (3) planetary gear
sets, all cooperating to achieve a greater torque
multiplication to a power output shaft.
Still, one other object of this invention is to
provide a continuously variable transmission which is °
sturdy in construction; provided with a minimum amount of
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movable parts relative to power transmission apparatuses;
utilizing a plurality of variable viscous clutch or
,, coupling means, a common ring gear means, a plurality of
spaced power planetary gear sets all engagable with the
common ring gear means to achieve a fuel saving,
efficient, continuously variable power output; and
substantially maintenance free.
Various other objects, advantages, and features of
the invention will become apparerit to those skilled in
the art from the following discussion, taken in
conjunction with the accompanying drawings, in which:
FIGURES OF THE INVENTION
Fig. 1 is a schematic cross sectional view of a
transmission housing and operating assembly utilizing a
continuously variable transmission utilizing variable
viscous couplings of this invention; and
Fig. 2 is a schematic cross sectional view of the
transmission housing and operating assembly utilizing a
continuously variable transmission utilizing variable
viscous couplings being a second embodiment of this
invention.
The following is a discussion and description of
preferred specific embodiments of the continuously
variable transmission utilizing variable viscous
couplings of this invention, such being made with
reference to the drawings, whereupon the same reference
s numerals are used to indicate the same or similar parts
and/or structure. It is to be understood that such
discussion and description is not to unduly limit the
scope of the invention.
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On referring to the drawings in detail, and in
particular to Fig. 1, a continuously variable ,
transmission utilizing variable viscous couplings of this
invention, indicated generally at 12, is operable to °
receive a power input supply, such as an internal
combustion engine from a vehicle, and transfer this into
a continuously variable power output supply.
The continuously variable transmission utilizing
variable viscous couplings 12 is hereinafter referred to
as "continuously variable transmission 12" and includes
an outward enclosure or stationary transmission housing
14.
The continuously variable transmission 12 includes
1) a power input means 16; 2) an elongated common ring
gear means 18 operably connected to the power input means
16; 3) a center planetary and reverse clutch means 20
which is operably connected to the common ring gear means
18 and the power input means 16; and 4) a power output
means 22 operably connected to the center planetary and
reverse clutch means 20 and the common ring gear means
18.
The power input means 16 includes a power input
shaft 24 connected to an input planetary gear assembly
26. The power input shaft 24 is rotatably mounted within
an input shaft bearing member 28.
The input planetary gear assembly 26 includes an
input sun gear member 30 engagable with input planet gear
members 32 for operation in a known conventional manner "
as a power planetary gear set. Power planetary gear sets
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can operate with one or a plurality of input planet gear
members 32 but the use of three is normally preferred.
The input sun gear member 30 includes a sun gear
support body 34 connected to the power-input shaft 24 and
having outer peripheral sun gear teeth members 36 thereon
engagable with respective ones of the input planet gear
members 32.
Each input planet gear member 32 includes 1) a
central bearing member 38; 2) a planet gear support body
40; and 3) outer peripheral planet gear teeth members 42.
The planet gear teeth members 42 are engagable with the
sun gear teeth members 36 and further with a portion of
the common ring gear means 18 for operation as to be
described.
The common ring gear means 18 includes 1) a common
ring gear member 44; 2) a start variable viscous clutch
or coupling means 46 with a portion thereof connected to
the stationary transmission housing 14 and another
portion connected to an outer portion of the common ring
gear member 44; and 3) a ratio variable viscous clutch or
coupling means 48 having a portion thereof connected to
the common ring gear member 44 and another portion
connected to the power output means 22 for a variable
power-output in a manner to be explained.
The common ring gear member 44 is provided with
three spaced sets of ring gear teeth members 50 for
engagement with respective ones of power planetary gear
sets as will be described. The sets of ring gear teeth
' members 50 could be a continuous integral ring abutting
the ratio variable viscous clutch 48.
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The start variable viscous clutch 46 includes 1)
outer fixed clutch plates 52 which are connected to an
adjacent portion of the stationary transmission housing
14; 2) innerrotatable clutch plates 54 which are
connected to an outer surface of the common ring gear '
member 44 and rotatable therewith; and. 3) a clutch
actuator piston member 56 which is operable to engage and
disengage the outer fixed clutch plates 52 and the inner
rotatable clutch plates 54 through use of a viscous
fluid. The use and operation of a viscous clutch or
coupling is well known in the prior art as a means for
transferring power during a transmission operation.
The ratio variable viscous clutch or coupling 48
includes 1) outer movable clutch plates 58 which are
secured to an inner surface and rotatable with the common
ring gear member 44; 2) inner movable clutch plates 60
which are secured to a portion of the power output means
22 and rotatable therewith in a disengaged condition; and
3) a ratio clutch actuator piston member 61 which is
operable to control rotation of the outer movable clutch
plates 58 and the inner movable clutch plates 60 from a
disengaged to a partially engaged to an engaged or locked
condition.
The. operation of the ratio variable viscous clutch
48 is known in the prior art utilizing a viscous fluid to
achieve variable speed rotation between the outer movable
clutch plates 58 and the inner movable clutch plates 60.
The center planetaryand reverse clutch means 20
includes a center planetary gear assembly 62 connected to '
a reverse variable viscous clutch or coupling 64.
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The center planetary gear assembly 62 includes a
center hollow sun gear assembly 66 operably engagable
with a center planet gear assembly 68. The center hollow
sun gear assembly 66 includes a center sun gear member 72
having a sun gear support body 70 provided with outer
center sun gear teeth members 74 engagable with the
center planet gear assembly 68.
The center planet gear assembly 68 includes a
plurality of center planet gear members 75 thereof, each
includes 1) a center bearing member 76; 2) a center
planet support body 78; and 3) outer peripheral center
planet gear teeth members 80.
Each set of respective center planet gear teeth
members 80 are engagable with the sun gear teeth members
74 on the center sun gear member 72 and the ring gear
teeth members 50 on the common ring gear member 44 in a
known manner.
The reverse variable viscous clutch 64 includes 1) a
clutch support input or input carrier member 82 connected
to the sun gear support body 70 of the center sun gear
member 72; 2) reverse movable clutch plates 84 connected
to the input carrier member 82; 3) reverse fixed clutch
plates 86 secured to an adjacent portion of the
stationary transmission housing 14; and 4) a reverse
clutch actuator piston member 88 operable to selectively
control a viscous coupling between the reverse movable
t clutch plates 84 and the reverse fixed clutch plates 86
in a manner known in the prior art with the use of
viscous fluid clutches.
The power output means 22 includes 1) a planetary
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gear support member or center carrier member 90 having an
outer portion thereof supported within respective ones of
the center bearing members 76 of the center planet gear
members 75 of the center planetary gear assembly 62; 2) a
control planetary gear assembly 92 operably connected to
the center carrier member 90 and adjacent ring gear teeth
members 50 on the common ring gear member 44; and 3) an
output shaft member 94 which is connected to the control
planetary gear assembly 92.
The control planetary gear assembly 92 includes 1) a
control sun gear assembly 96 which is connected to the
center carrier member 90 and the output shaft member 94;
and 2) a control planetary gear assembly 98.
The control sun gear assembly 96 includes 1) a
control sun gear shaft member 102 which is connected to
the center carrier member 90 for~conjoint rotation
therewith; and 2) a control sun gear member 104 connected
to the control sun gear shaft member 102 and the output
shaft member 94.
The control sun gear member 104 is provided with a
control sun gear support body 106 and having outer
peripheral control sungear teeth members 108 which are
in engagement with portions of the control planetary gear
assembly 98.
The control planetary gear assembly 98 includes
control planetary gear members 12, each mounted on a
respective bearing member 114 which are rotatably
connected to the control carrier member 63.
Each control planetary gear member 112 is provided '
with a support body member 118 which is connected to
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outer peripheral control gear teeth members 120.
The control gear teeth members 120 are engagable
with the control sun gear teeth members 108 of the
control sun gear member 104 and further engagable with
the ring gear teeth members 50 on the common ring gear
member 44.
The control carrier member 63 has one portion
supported in respective ones of the bearing members 114
and an outer end is connected to the inner movable clutch
plates 60 of the ratio variable viscous clutch 48.
The output shaft member 94 is mounted within an
output shaft bearing member 122 so as to be rotatable
therein.
As shown in Fig. 2, a second embodiment of the
invention for heavy duty use includes a continuously
variable transmission utilizing variable viscous
couplings 121 which is substantially identical tothe
first embodiment except having a different power output
means 124 and the control planetary gear assembly 92 has
been changed to an output planetary gear assembly 125.
More specifically, the continuously variable
transmission 121 utilizes the previously described 1)
power input means 16; 2) common ring gear means 18; and
3) center planetary and reverse clutch means 20. All of
the elements therein have been described in the
explanation of the first embodiment of Fig. 1.
r The power output means 124 includes 1) an output
planetary gear assembly 125; 2) an output carrier member
127 connected to the output planetary gear assembly 125;
and 3) a transverse support member 128 connected to the
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output carrier member 127 and to the power output shaft
94.
The output planetary gear assembly 125 includes a
sun gear member 104 connected to the power output shaft
94 and planet gear members 112 as previously described in '
the first embodiment.
The sun gear member 104 includes a sun gear support
body 106 with sun gear teeth members _L08 engagable with
planet gear teeth members 120 of the planet gear members
112.
The output planetary gear assembly 125 operates in a
torque multiplication function instead of a -control
function achieved by the control planetary gear assembly
92 in the first embodiment of Fig. 1.
USE AND OPERATION OF THE INVENTION
In the use and operation of the continuously
variable transmission 12 of this invention as noted in
Fig. 1, three power planetary gear set=s in series are
utilized with three viscous fluid coupling means to
achieve the new and novel variable power output of this
invention.
More specifically, the continuou.aly variable
transmission 12 utilizes three power planetary gear sets,
namely 1) the input planetary gear assembly 26; 2) the
center planetary gear assembly 62; and 3) the control
planetary gear assembly 92 all used in series with the
common ring gear member 44. ,
The three power planetary gear sets 26, 63, 92 are
utilized directly or indirectly with three variable
viscous clutches, namely, 1) the start. variable viscous
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clutch 46; 2) the ratio variable viscous clutch 48; and
3) the reverse variable viscous clutch 64.
The continuously variable transmission 12 provide
four modes or operations, namely 1) neutral; 2) a fixed
' ratio reverse; 3) a fixed ratio low drive; and 4) a
continuously variable drive range.
The following is a description of the operation in
the various aforementioned four modes of operation.
In the neutral operation, the power input shaft 24
is connected to and rotates the input sun gear member 30
which rotates the input planet gear members 32 through
engagement of the sun gear teeth members 36 and the
planet gear teeth members 42.
The input carrier member 82 is held stationary due
to a load on the output shaft member 94.
The input sun gear member 30 drives the input planet
gear members 32 in a reverse direction. The input planet
gear members 32 drive the common ring gear member 44 in a
reverse direction as the start variable viscous clutch
46, the ratio variable viscous clutch 48, and the reverse
variable viscous clutch. 64 are disengaged. The common
ring gear member 44 is freely rotated and no power is
transmitted from the power input shaft 24 to the power
output shaft 94.
gF~.7ER~E OPERATION - FIG. 1
In the reverse operation, the power input shaft 24
drives the input sun gear member 30 and interconnected
input planet gear members 32. At this time, control
fluid pressure is applied to the reverse variable viscous
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clutch 64, thus quickly closing to a fully engaged
condition.
The input carrier member 82 is held.against rotation
by the engaged reverse variable viscous clutch 64. The
input sun gear member 30 then drives 'the input planet '
gear members 32 in reverse.
The input planet gear members 32 drive the common
ring gear member 44 in reverse. Concurrently, the common
ring gear member 44 drives the center planet gear members
75 about the center sun gear member 72 which is connected
to the input carrier member 82 and held against movement
by the reverse variable viscous clutch 64.
The rotating center planet gear rnembers 75 then
drive the center carrier member 90 and the attached power
output shaft 94 in a direction reversed from the
direction of rotation of the power input shaft 24 with a
fixed torque increase depending on the size of gears
utilized.
TzOW A QP RATTn g
In the low range operation which is equivalent to a
start up forward operation, the power input shaft 24
rotates the input sun gear member 30 a.nd the input planet
gear members 32. Controlled viscous fluid pressure is
applied to the start variable viscous clutch 46 through
the clutch actuator piston member 56 to variably and
quickly close this clutch to the engaged condition.
The common ring gear member 44 is held stationary by
the start variable viscous clutch 46. The rotating input
planet gear members 32 react to the common ring gear '
member 44 being held against movement and rotates the
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input carrier member 82 forward with a torque
multiplication.
The center planet gear member 75 is driven by the
input carrier member 82 so that the center planetary gear
assembly 62 repeats the action of the planetary input
assembly 26 for a further torque increase. The power
output shaft 94 is driven forwardly by the center carrier
member 90 and the control planet gear members 112 are
freewheeling about the common ring gear member 44.
In the drive range operation, or known as a variable
ratio forward range operation, when a vehicle having the
continuously variable transmission 12 utilized therewith
attains a maximum low speed range, the start variable
viscous clutch 46 is opened by releasing control fluid
pressure on the clutch actuator piston member 56.
Concurrently, the ratio variable viscous.clutch 48 is
activated by applying a variable fluid pressure to the
ratio clutch actuator piston member 61.
The ratio variable viscous clutch 48 controls the
speed differential between the common ring gear member 44
and the control carrier member 63 thereby changing the
speed differential between the power input shaft 24 and
the power output shaft 94.
The range of torque multiplication is from the
maximum, depending on relative sizes of the gears,
generated by the power input shaft 24, the center
planetary gear assembly 62, and the input planetary gear
assembly 26 which are in series to the minimum of one to
one.
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The following is a description of the modes of
operation of the second embodiment--of the continuously
variable transmission 121 as notedin Fig. 2. ,
~j TT AT. C_~PFRATTC_11~7 - IG.
In the neutral operation, the power input shaft 24 '
is connected to and rotates the input sun gear member 30
which rotates the input planet gear members 32 in a
reverse direction through engagement ~f-the sun gear
teeth members 36 and the planet gear 'teeth members 42.
The input carrier member 82 rotates to drive the
center sun gear member 72 which will rotate the center
carrier member 90. This drives the output sun gear
member 104 which, in turn, drives the output planet gear
members 112.
The power output shaft 94 and ini=erconnected
transverse shaft member 128 are held :stationary by a load
on the power output shaft 94.
The input planet gear members 32 drive the common
ring gear member 44 in a reverse direction as the start
variable viscous clutch 46, the ratio variable viscous
clutch 48, and the reverse variable viscous clutch 64 are
disengaged. The common ring gear member 44 is freely
rotated and no power is transmitted from the power input
shaft 24 to the power output shaft 94. The center
planetary gear-assembly 62 and the output planetary gear
assembly 125 are freewheeling and not driving the power
output shaft 94.
_R_F~jF F QP RA TON --- FI 2
In the reverse operation, the power input shaft 24
drives the input sun gear member 30 and interconnected
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input planet gear members 32. At this time, a control
fluid pressure is applied to the reverse variable viscous
clutch 64, quickly closing the subject clutch to an
engaged condition.
The input carrier member 82 is held against rotation
by the closed reverse variable viscous clutch 64. The
input sun gear member 20 then drives the input planet
gear members 32 in reverse.
The rotating input planet gear members 32 drive the
common ring gear member 44 in reverse. Concurrently, the
common ring gear member 44 drives the center planet gear
assembly 68 or, specifically, the center planet gear
members 75, about the center sun gear member 72 which is
held stationary by the input carrier member 82 and the
engaged reverse variable viscous clutch 64.
The center planet gear members 75 then drive the
center carrier member 90 and the attached. output
planetary gear assembly 125 including the output carrier
member 127, the transverse output support member 128, and
the power output shaft 94 in a reverse direction with a
fixed torque increase depending on the size of the gears
utilized.
LOW RANGE OPERATION - FIG. 2
In the description of the low range operation which
is equivalent to a start up forward operation, the power
input shaft 24 rotates the input sun gear member 30 and
connected input planet gear members 32. Controlled fluid
pressure is applied to the start variable viscous clutch
46 through the clutch actuator piston member 56 to close
this clutch from a disengaged to a fully engaged
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condition.
The common ring gear member 44 is held stationary by
the start variable viscous clutch 46. The input sun gear ,
member 30 drives the input planet gear members 32 which
react to the common ring gear member 44 being held '
against movement. -The input planet gear members 32 drive
the input carrier member 82 forward with a torque
multiplication.
The center hollow sun gear assembly 66 is driven by
the input carrier member 82 so that the center planetary
gear assembly 62 repeats the action of the input
planetary assembly 26 for a further torque increase.
The output sun gear member 104 is driven by the
output carrier member 127 which drives the output planet
gear members 112 to repeat the action of the input
planetary assembly 26 for a third torque increase. The
rotational movement of the output carrier, member 127 and
interconnected transverse output support member 128
operate to drive the power output shaft 94 forwardly.
DRTVE RANGE OPERATION - FIG 2
In the drive range operation, or known as a variable
ratio forward range operation, when a vehicle having the
continuously variable transmission 12 is utilized
therewith attains a maximum low speed range, the start
variable viscous clutch 46 is opened by releasing the
control fluid pressure on the clutch actuator piston
member 56. The ratio variable viscous clutch 48 is
activated by applying a variable fluid control pressure
to the ratio clutch actuator piston member 61. '
The ratio variable viscous clutch 48 controls the
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speed differential between the common ring gear member 44
and the output carrier member 127 thereby changing the
speed differential between the power input shaft 24 and
the power output shaft 94.
' The range of torque multiplication is from the
maximum generated by 1) the power input shaft 24; 2) the
input planetary assembly 26; 3) the center planetary gear
assembly 62; and 4) the output planetary gear assembly
125, which are in a series, to the minimum of one to one.
The status and/or rotation of the major elements of
the continuously variable transmission 12 in the modes of
operation are indicated as follows:
Forward Rotation +
Reverse Rotation -
Zero Rotation Z
Engaged E
Disengaged D
Variable V
Fig. 1 Chart
ELEMENTS NEUTRAL LOW RANGE DRIVE RANGE REVERSE
OPERATION OPERATION OPERATION OPERATION
Power Input + + + +
Shaft 24
Input Sun
Gear
Member 30
Input Carrier + + + Z
Member 82
Center Sun
Gear Member
72
Center Z + + -
Carrier
Member 90
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Power Output
Shaft 94
Control - + -~- . +
Carrier
Member 63
Common Ring - Z a- -
Gear
Member 44
Reverse D D D E
Variable
Viscous
Clutch 64 -
Start D E D D
Variable
Viscous
Clutch 46
Ratio D D V D
Variable
Viscous
Clutch 48
F ig. 2 Chart
ELEMENTS NEUTRAL LOW RANGE DRIVE RANGE REVERSE
OPERATION OPERATION OPERATION OPERATION
Power Input + + + +
Shaft 24
Input Sun
Gear
Member 30
Input Carrier+ + + Z
Member 82
Center + + + -
Carrier
Member 90 '
Output Sun
Gear Member
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104
Output Z + + -
Carrier
Member 127
Power Output
Shaft 94
Common Ring - Z + -
Gear
Member 44
Reverse D D D E
Variable
Viscous
Clutch 64
Start D E D D
Variable
Viscous
Clutch 46
Ration D D V D
Variable
Viscous
Clutch 48
On reading the Fig. 1 power flow chart, the status
and/or rotation of the major elements of the continuously
variable transmission 12 are shown with the various
symbols utilized to fully describe an operation of the
continuously variable transmission 12.
In the neutral operation in the embodiment of the
Fig. 1 chart, the power input shaft 24, the input sun
gear member 30, the input carrier member 82 and the
center sun gear member 72 are rotated forwardly. The
center carrier member 90 and the power output shaft 94
are in-a condition of zero rotation due to a load on the
power output shaft 94.
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The control carrier member 63 and the common ring
gear member 44 are in the condition of reverse rotation.
At this time, the variable viscous clutches 46, 48, 64
are in a disengaged condition which causes a zero
rotation in the power output shaft 94.
In the low range operation of the Fig. 1 chart, it
is noted that the power input shaft 24, the input sun
gear member 30, the input carrier member 82, the center
sun gear member 72, the center carrier member 90, the
power output shaft 94, and the contro3 carrier member 63
are all in the condition of forward rotation. At this
time, the common ring gear member 44 has zero rotation
thereof .
The reverse variable viscous clutch 64 is disengaged
as with the ratio variable viscous clutch 48. The start
variable viscous clutch 46 is engaged which causes
rotation of the power output shaft 94 in the low range
operation.
In the drive range operation of the Fig. 1 chart, it
is noted that the power input shaft 24, the input sun
gear member 30, the input carrier member 82, the center
sun gear member-72, the center carrier member 90, the
power output shaft 94, the control carrier member 63, and
the common ring gear member 44 are all in a forward
rotation mode_
In this condition, the reverse variable viscous
clutch 64 and the start variable viscous clutch 46 are in
the disengaged condition. At this time, the ratio
variable viscous clutch 48 is variably engaged so as to
control drive speed output to the output shaft member 94.
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On referring to the reverse operation in the Fig. 1
chart, it is noted that the power input shaft 24 and the
input sun gear member 30 plus the control carrier member
63 are in the condition of forward rotation. The input
carrier member 82 and the center sun gear member 72 are
held at zero rotation.
The center carrier member 90 and the power output
shaft 94 in conjunction with the common ring gear member
44 are in the condition of reverse rotation.
At this time, the reverse variable viscous clutch 64
is in the engaged condition while, concurrently, the
start variable viscous clutch 46 and the ratio variable
viscous clutch 48 are in the disengaged condition.
On referring to the Fig. 2 chart, being the second
embodiment of the invention, it sets forth that the
rotation and condition of major elements during this mode
of operation would be substantially identical to that in
the first embodiment of Fig. 1.
The primary difference is connection of the power
output shaft 94 to the third power planetary gear set or
the output planetary gear assembly 125. In the first
embodiment, the control planetary gear assembly 92 acts
as a means of speed control, and in thesecond embodiment
(Fig. 2), the output planetary gear assembly 125 operates
as a third step of torque multiplication.
In the Fig. 2 chart, the center carrier member 90 is
connected to and rotates with the output sun gear member
104 and not directly to the power output shaft 94. One
additional change is the power output shaft 94 is
connected to and rotates with the output carrier member
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It is noted that the continuously variable
transmission 12 or 121 utilizes three power planetary
gear sets connected in a series in combination with three
viscous fluid clutch means, each associated with -
respective ones of the power planetary gear sets in
combination with the common ring gear member 44 to
achieve the continuously variable power output from the
power input shaft 24 to the power output shaft 94.
This cooperation operates to achieve a smooth and
variable transmission of power to the output shaft member
94 and operable to change conditions from a neutral
condition; a low range condition;' a drive range condition
achieving a variable torque multiplication condition; and
to a reverse condition.
The continuously variable transmission of this
invention provides a continuously variable power output
which is relatively economical to manufacture compared to
prior art structures; reliable in use; operable to
provide a variable degree of torque multiplication;
providing various modes of operation such as neutral, low
range, drive range or a reverse operation from a minimum
of one to one to a maximum torque multiplication; and
substantially maintenance free.
While the invention has been desr_ribed in
conjunction with preferred specific embodiments thereof,
it will be understood that this description is intended
to illustrate and not to limit the scope of the
invention, which is defined by the following claims. '
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