Note: Descriptions are shown in the official language in which they were submitted.
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RADIAL DIAPHRAGM PUMP
FIELD OF THE INVENTION
The present invention relates to a pump comprising a drive shaft and a
plurality of diaphragm assemblies circumferentially spaced about the drive
shaft and
arranged for reciprocation in a radial direction relative to the drive shaft
in response to
rotation of the drive shaft.
BACKGROUND
In the field of soil remediation, it is common to use a vacuum pump to
extract vapours from the soil, for example hydrocarbon vapours in the soil
contaminated in the oil industry and the like. Because soil remediation often
occurs in
remote locations, it is desirable to drive the vacuum using passive means, for
example solar or wind power. Attempts to drive pumps in soil remediation using
wind
power are described in US patent 6,109,358 by McPhee et at. The efficiency of
the
conversion of wind power to mechanical pumping is somewhat limited by the use
of
conventional reciprocating pumps in the prior art.
Various improvements to pumping devices are disclosed in United
States Patents 4,963,075 by Albertson and 6,574,537 by Olson; and United
States
Application Publication No. 2005/0271525 by Muramatsu et at. In the first two
noted
examples, no means are provided to directly connect the diaphragm of a
diaphragm
pump to drive shaft which results in some losses of efficiency. In the later
document,
a cam drive is provided which positively drives outward reciprocation of a
plurality of
diaphragms, however, there is a loss in efficiency because no means are
provided to
positively drive the return of the diaphragms.
SUMMARY OF THE INVENTION
According to one aspect of the invention there is provided a pump
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comprising:
a housing;
a drive shaft supported on the housing for rotation about a drive axis
extending in a longitudinal direction of the shaft;
an output member supported on the shaft radially offset from the drive
axis so as to be arranged for eccentric rotation about the drive axis;
a plurality of pumping assemblies supported on the housing, each
pumping assembly comprising:
a pump shaft supported for linear sliding movement relative to the
housing along a respective pump axis oriented in a radial direction relative
to the drive
axis;
a diaphragm oriented transversely to the drive axis and being
joined in sealing engagement to the housing about a peripheral edge of the
diaphragm so as to define a wall portion of a respective pumping chamber;
the diaphragm being flexible and being fixed to the pump shaft at
an intermediate portion spaced from the peripheral edge such that the
intermediate
portion of the diaphragm is movable with the pump shaft relative to the
housing;
an inlet check valve in communication with the pumping chamber
so as to be arranged to allow air to be drawn into the pumping chamber only
when the
pump shaft is displaced in a first direction; and
an outlet check valve in communication with the pumping
chamber so as to be arranged to allow air to be expelled from the pumping
chamber
only when the pump shaft is displaced in a second direction opposite to the
first
direction; and
a linkage assembly connecting the output member to the pump shafts of
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the pumping assemblies such that the pump shafts are arranged to be
reciprocated in
response to rotation of the drive shaft.
By providing a linkage which connects pump shafts to the drive shaft
where the pump shafts themselves are directly connected to a portion of the
diaphragm, the diaphragms of the pumping assemblies are positively
reciprocated
throughout the range of motion thereof with a single input rotation of the
drive shaft for
converting a rotary input to an efficient multi-chamber pumping. The use of
pump
shafts which are supported for linear sliding movement and coupled to the
diaphragms ensures that the diaphragms are isolated from the oscillating
movement
of the output member of the drive shaft to protect the material of the
diaphragms. Any
number of pumping assemblies may be provided evenly spaced about the drive
axis,
for example 3 to 8 diaphragm pumping assemblies can be driven from a single
oscillating wheel by the drive shaft. The membranes are preferably
reciprocated by
floating push rods or links connecting pump shafts of the diaphragms to the
oscillating
wheel in which only one of the links is fixed to the oscillating wheel to
adequately
guide the oscillation of the wheel as the drive shaft rotates. The pump shafts
act as a
precise guiding system which run on ball bearings for optimal efficiency while
maintaining adequate support to the membranes. The linkage can be arranged to
permit a membrane working diameter in the range of 10 to 30 percent.
The membrane pump described herein comprises a simple and compact
radial design with multiple chambers allowing for easy output adjustment. The
pump
is operable through a wide operating range of 0 - 500 revolutions per minute
and
through a wide temperature range of -40 to +70 degrees Celsius. The load on
the
pump is self-adjustable so that no safety valves are necessary. Furthermore,
minimum service is required as the membrane guidance system assures longevity
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and reliability while remaining environmentally friendly as no lubricants are
required.
Preferably the diaphragm of each pumping assembly defines the wall
portion at an inner side of the respective pumping chamber such that an
exterior side
of the diaphragm which faces away from the drive axis is in open communication
with
the respective pumping chamber.
Preferably the first direction of movement of each pump shaft
corresponds to a movement of the pump shaft towards the drive axis and the
second
direction of movement of each pump shaft corresponds to a movement of the pump
shaft away from the drive axis.
Preferably interior sides of the respective diaphragms which face
inwardly towards the drive axis communicate with a common drive chamber of the
housing in which the linkage assembly is located in said common drive chamber
of
the housing.
Preferably each pump shaft extends radially outward from the
intermediate portion of the respective diaphragm to an outer end supported in
a
sleeve mounted on the housing for linear sliding movement of the pump shaft
relative
to the sleeve.
Preferably at least one roller bearing is provided in communication
between each pump shaft and the respective sleeve.
Preferably each pump shaft extends radially outward from an outer side
of the respective diaphragm and each diaphragm includes a pivot mount at an
inner
side of the diaphragm which is connected to the respective pivot shaft through
the
diaphragm.
Preferably the linkage assembly comprises an oscillating drive member
coupled to the output member on the shaft for rotation relative to the output
member
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about an offset axis of the output member which is parallel to the drive axis
and a link
member coupled between each pump shaft and the oscillating drive member.
Preferably each link member is pivotally coupled to the respective pump
shaft about a link axis oriented parallel to the drive axis.
5 Preferably the link axes are oriented parallel to the drive axis.
Preferably only one of the link members is connected in fixed relation to
the oscillating drive member.
Preferably the other link members are pivotally connected to the
oscillating drive member.
Preferably the pump assemblies are circumferentially spaced apart
about the drive axis such that the pump axes of the pump shafts lie in a
generally
common plane.
Preferably the linkage assembly is coupled between the output member
and the pump shafts such that the pump shafts are arranged to be sequentially
reciprocated relative to the housing.
Preferably the housing comprises an end wall oriented perpendicularly
to the drive axis and supporting the drive shaft rotatably therethrough and a
plurality
of side walls joined to the end wall so as to define a polygonal perimeter
about the
drive axis in which each side wall of the polygonal perimeter of the housing
supports a
respective one of the pumping assemblies therein.
Preferably the pump is provided in combination with a wind turbine
assembly having a turbine rotor arranged to be rotated by the wind and an
output
shaft mechanically coupled to the turbine rotor in which the output shaft is
directly
mechanically coupled to the drive shaft of the pump.
Preferably the turbine rotor is supported on an upright supporting
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structure and the output shaft extends vertically between the turbine rotor at
a top end
of the upright supporting structure and the drive shaft of the pump at a
bottom end of
the upright supporting structure in which the drive shaft of the pump is
coupled to the
output shaft of the wind turbine such that the pump shafts extend radially
outward
from a vertical axis of the output shaft of the turbine.
One embodiment of the invention will now be described in conjunction
with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of the pump connected to a wind
turbine.
Figure 2 is a perspective view of a first end of a pump housing.
Figure 3 is a perspective view of an opposing second end of the pump
housing with the second end wall shown removed.
Figure 4 is a perspective view of the drive shaft and linkage assembly
coupled to the output member of the drive shaft shown separated from the
housing.
Figure 5 is a perspective view of the drive shaft and out put member.
Figure 6 is a longitudinal cross-sectional view of the drive shaft.
Figure 7 is an exploded perspective view of one of the pumping
assemblies.
Figure 8 is an exploded perspective view of the inlet and outlet check
valves of one of the pumping assemblies.
Figure 9 is an exploded perspective view of the connection between the
diaphragm and the respective pump shaft.
In the drawings like characters of reference indicate corresponding parts
in the different figures.
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DETAILED DESCRIPTION
Referring to the accompanying figures there is illustrated a pump
generally indicated by reference numeral 10. The pump 10 is well suited for
being
directly driven by a wind turbine 12.
In the illustrated embodiment, the wind turbine comprises an upright
mast 14 which supports a turbine rotor 16 at the top end thereof for rotation
about a
horizontal axis. A vertical output shaft 17 is mechanically coupled to the
turbine rotor
at the top end and extends vertically the height of the mast between the rotor
at the
top end and the pump 10 adjacent the bottom end.
In an alternative embodiment, the wind turbine may comprise a vertical
axis turbine in which the turbine rotor rotates about a vertical axis. The
vertical output
shaft in this instance is typically directly coupled for rotation together
with the rotor
about the vertical axis of the rotor.
The pump 10 generally comprises a housing 18 including a first end wall
20 formed by a flat plate having a plurality of side edges which define a
polygonal
perimeter of the housing. The housing 18 further comprises a plurality of side
walls
22 joined to the side edges of the first end wall respectively such that the
flat plates
forming the side walls respectively are oriented perpendicularly to the end
wall for
surrounding a hollow interior of the housing. The side walls span between the
first
end wall 20 at one end and a second wall (not shown) at the opposing end to
enclose
the interior of the housing. In the illustrated embodiment, the end walls are
square
such that there are four side walls 22 about the square perimeter of the first
end wall.
The pump further comprises a drive shaft 24 which is mounted in the
first end wall of the housing at a central location thereon so as to extend
through the
end wall for rotation about a drive axis extending in the longitudinal
direction of the
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drive shaft perpendicularly to the first end wall and parallel to the side
walls. The
drive shaft is supported by a sleeve 26 extending through a respective
aperture
through in the end wall and which is secured to the end wall by a suitable
bolt flange
28. The drive shaft 24 is supported for rotation relative to the surrounding
sleeve by
suitable bearings 30 at axially spaced positions towards opposing ends of the
sleeve.
In the illustrated embodiment, the drive shaft 24 is arranged to be
directly coupled to the output shaft of the turbine to provide a direct
mechanical
connection between the turbine rotor and the output shaft of the turbine and
in turn
between the output shaft and the drive shaft 24 of the pump. In this instance,
the
drive shaft of the pump is oriented in a vertical orientation in line with the
output shaft
17 of the turbine.
Alternatively, the output shaft 17 may be coupled to the drive shaft 24 of
the pump by a speed increaser or speed decreaser depending upon the expected
wind conditions. In yet further embodiments, a transmission belt, for example
a V-
belt, may be coupled between pulleys on the output shaft 17 and the drive
shaft 24
respectively to transfer the rotation of the output shaft 17 of the turbine to
the drive
shaft 24 of the pump at a selected ratio based upon the relative diameters of
the
pulleys.
The drive shaft includes an output member 26 fixed to an inner end of
the shaft within the interior of the housing. The output member is offset in a
radial
direction relative to the drive axis to define an offset axis which is
parallel and spaced
from the drive axis. Accordingly the output member rotates eccentrically about
the
drive axis together with rotation of the drive shaft.
The pump 10 further comprises a plurality of pumping assemblies 34
which are spaced evenly in a circumferential direction about the drive axis
such that
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one pumping assembly is supported in each one of the side walls 22 of the
housing.
Each pumping assembly is arranged for reciprocating movement along a
respective
pump axis oriented in a radial direction relative to the drive axis such that
the pump
axes are all located on a common plane which is perpendicular to the drive
axis.
Each pumping assembly includes a diaphragm 36 comprising a circular
member of flexible material which is mounted to span across a respective
aperture
formed in the side wall 22 of the housing. A peripheral edge of the diaphragm
is fixed
to the housing about the perimeter of the aperture in the side wall.
The pumping assembly further comprises an annular member 38 which
mounts onto the respective side wall of the housing such that the peripheral
edge of
the diaphragm is clamped between the annular member and the side wall of the
housing about the full perimeter of the diaphragm. A pair of annular gaskets
40 are
provided on opposing sides of the diaphragm for sealing between the annular
member 38 and the diaphragm as well as sealing between the diaphragm and the
housing about the annular perimeter of the diaphragm.
The annular member 38 defines a cylindrical wall about a central
pumping chamber defined by the annular member. The pumping chamber 42
communicates directly with the exterior side of the respective diaphragm such
that the
diaphragm defines an inner side wall portion of the resulting pumping chamber.
The
diaphragm spans perpendicularly to the respective pump axis of the pumping
assembly.
A circular plate 44 defines the outer side wall of the cylindrical pumping
chamber. The circular plate is rigid and fastened about its periphery to the
annular
member and in turn to the housing by common fasteners which extend through the
circular plate, the annular member and the peripheral edge of the side wall of
the
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housing about the aperture receiving the diaphragm thereon. An additional o-
ring
seal 46 is secured between the circular plate and the annular member 38 for
sealing
engagement therebetween.
Each pumping assembly further comprises a pump shaft 48 supported
5 on the circular plate 44 by a suitable sleeve 50 slidably receiving the pump
shaft 48
therein. The sleeve 50 is anchored at an inner end at a central location on
the plate
44 using a suitable bolt flange. The sleeve 50 extends outwardly in a radial
direction
from the drive axis coaxially with the pump axis to an outer end which is
enclosed by
a threaded cap 52. The pump shaft extends in the longitudinal direction of the
sleeve
10 and is supported for linear sliding movement therein by a plurality of
roller bearings 54
at circumferentially spaced and longitudinally spaced positions on the shaft
adjacent
the outer end of the pump shaft. The bearings are moveable with the pump shaft
for
rolling movement along the inner surface of the sleeve to guide the linear
sliding
movement of the pump shaft relative to the housing.
An inner end of each pump shaft 48 is fixed to a corresponding
intermediate portion of the respective diaphragm 36 at a central location
thereon. A
pair of circular support plates 56 having a diameter which is smaller than the
diaphragm are clamped onto opposing sides of the diaphragm at the fixed
connection
of the pump shaft to the diaphragm to limit excessive flexing of the diaphragm
relative
to the pump shaft adjacent the connection therebetween. A rigid fastener 58
extends
through a central aperture in the diaphragm to clamp the two support plates 56
to
opposing sides of the diaphragm and to clamp a rigid mount 60 at the interior
side of
the diaphragm to the inner end of the pump shaft located at the exterior side
of the
diaphragm.
The diaphragm is formed of flexible material such that the intermediate
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portion of the diaphragm coupled to the shaft moves together with the shaft
for linear
sliding movement along the respective radially oriented pump axis relative to
the
housing while the peripheral edge of the diaphragm remains clamped in fixed
relationship to the housing.
Each pumping assembly includes a respective inlet check valve 62 and
an outlet check valve 64. Each of the check valves includes a respective valve
housing 66 defining a valve chamber therein in alignment with respective
openings 68
in the end plate 44 of the respective pumping chamber. A one-way flap valve
member 70 overlaps the openings 68 on one side of the plate for allowing
communication of air or gasses between the respective valve chamber and the
pumping chamber in one direction only.
At the inlet check valve 62, the flap valve member is located at the
interior side of the circular plate so that gas can only enter from the valve
chamber
into the pump chamber but is blocked from exiting the pump chamber
therethrough.
At the outlet check valve, the flap valve member 70 spans the outer side of
the
openings in the circular plate so that gas is only permitted to pass from the
pumping
chamber outwardly to the respective valve chamber.
Suitable o-rings 72 provide sealing engagement between each valve
housing 66 and the outer side of the circular plate 44. Tubing 74 joins all of
the inlet
check valves 62 to a common inlet manifold 76 as well as joining all of the
outlet
check valves 64 to a common outlet manifold 78.
A linkage assembly connects the output member on the drive shaft to
the pump shafts of the pumping assemblies such that the pump shafts are
arranged
to be reciprocated in response to rotation of the drive shaft. The linkage
includes an
oscillating drive member 80 which is mounted on the output member for relative
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rotation therebetween about the offset axis of the output member. In this
manner the
oscillating drive member is suited for oscillating movement about the drive
axis as the
drive shaft is rotated.
A plurality of link members are provided in which each link member 82 is
.5 coupled between a respective pump shaft and the oscillating drive member.
The link
member comprises a rigid member supported by a suitable bearing 84 at an outer
end
for pivotal connection to the rigid mount 60 of the respective diaphragm. The
bearing
couples the link member for pivotal movement relative to the rigid mount about
a link
axis oriented parallel to the drive axis.
One of the link members 82 has an inner end which is fixed in position
and orientation relative to the oscillating drive member. All of the remaining
link
members 82 have an inner end coupled by a suitable bearing 86 for pivotal
movement
relative to the oscillating drive member about respective axes which are also
oriented
parallel to the drive axis.
The oscillating drive member and the link members are all located within
a common drive chamber defined by the hollow interior of the housing. The
interior
sides of the diaphragms are open to the common drive chamber as the interior
sides
face inwardly towards the drive axis.
Each pump shaft is supported to extend generally radially outward from
the exterior sides of the respective diaphragms such that each pump shaft is
moveable in a first direction inwardly towards the drive axis and in a second
direction
outwardly away from the drive axis. When displaced in the first direction, the
respective pump chamber is expanded such that air or gas is drawn inwardly
through
the respective inlet check valve. When displaced in the opposing second
direction,
the corresponding pump chamber at the exterior side of the diaphragm is
contracted
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such that air or gas is expelled outwardly through the respective outlet check
valve.
The linkage couples all of the pump shafts to the oscillating members
such that as the oscillating drive member is oscillated eccentrically about
the drive
axis with an input drive rotation of the drive shaft, all of the pump shafts
are
reciprocated sequentially to cause a sequential pumping of the pumping
assemblies.
The joining of the inlets to the common inlet manifold 76 thus provides a
relatively
continuous suction while the outlets joined to the outlet manifold provide a
relatively
continuous supply of pumped fluid under pressure.
In the field of soil remediation, one pump and turbine assembly can be
provided for connection of the inlet manifold to an underground suction
manifold at
one location while a second turbine and pump assembly can be provided for
connection of the outlet manifold to an underground pressurized manifold at a
second
location. In this instance, vapours are drawn out at the first location while
fresh air is
pumped into the second location.
Since various modifications can be made in my invention as herein
above described, and many apparently widely different embodiments of same made
within the spirit and scope of the claims without department from such spirit
and
scope, it is intended that all matter contained in the accompanying
specification shall
be interpreted as illustrative only and not in a limiting sense.
