Note: Descriptions are shown in the official language in which they were submitted.
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VANE PUMPS AND METHODS OF OPERATING SAME
TECHNICAL FIELD
[0001] The present invention relates generally to vane pumps, and, more
particularly, to im-
proved stackable over-center vane pumps and methods of operating the same.
BACKGROUND ART
[0002] Vane pumps are, of course, known. These devices generally have a rotor
mounted
for rotation within a cavity in a body or member. A plurality of
circumferentially-spaced
slots extends radially into the rotor from its outer surface. A vane is
slidably mounted in each
slot, and has a distal end operatively arranged to engage a portion of the
member wall defin-
ing the cavity. Often, the vanes are urged to move outwardly from the rotor by
centrifugal
force when the rotor rotates. These vanes define with the rotor and the
member, a series of
circumferentially-spaced chambers between a fluid inlet and a fluid outlet.
The volumes of
these chambers progressively increase or decrease, depending on the direction
of rotation, as
the rotor rotates within the member. These chambers carry fluid from the fluid
inlet to the
fluid outlet. Examples of such vane motors are representatively shown and
described in U.S.
Patent No. 4,619,594, U.S. Patent No. 5,037,283 and U.S. Patent No. 6,763,797.
[0003] However, with such prior art vane pumps, it is normally necessary to
reverse the di-
rection of rotor rotation to change the direction of fluid flow through the
pump.
[0004] Accordingly, it would be desirable to provide improved vane pumps that
would al-
low the direction of fluid flow through the pumps to be reversed without
having to change the
direction of rotor rotation.
DISCLOSURE OF THE INVENTION
[0005] With parenthetical reference to the corresponding parts, portions or
surfaces of the
disclosed embodiment, merely for purposes of illustration and not by way of
limitation, the
present invention broadly provides improved vane pumps.
[0006] In one form, the improved vane pump (20) includes: a housing (21); a
shaft (22)
having a shaft axis ( y I), the shaft being mounted on the housing for
rotation about the shaft
axis; a first motor (23) operatively arranged to selectively rotate the shaft;
a rotor (24)
mounted for rotation with the shaft, the rotor having a plurality of
circumferentially-spaced
slots (26); a member (28) having a surface (29) and having a member axis (y2-
y2), the mem-
ber being movable relative to the shaft axis through a permissible range of
motion (30) which
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includes portions ("-1", "+1") on either side of a null position ("O");
wherein the member axis
(y2-y2) is coincident with the shaft axis (y 1-y 1) when the member is in the
null position; a vane
(32) movably mounted in each rotor slot and having a distal end arranged to
sealingly and
wipingly engage the member surface; the vanes defining with the rotor and
surface a plurality
of chambers (33A-33F), the individual volumes of the chambers varying as a
function of the
relative position between the rotor and surface; the housing having two fluid
passageways
(34, 34) operatively arranged to communicate with two of the chambers as a
function of the
angular position of the rotor relative to the housing; a second motor (31)
operatively arranged
to selectively move the member relative to the shaft axis through the
permissible range of
motion; wherein movement of the member off-null in one direction along the
range of motion
will enable fluid flow in a first direction between the ports; and wherein
movement of the
member off null in the opposite direction along the range of motion will
enable fluid flow in
the opposite direction between the ports.
[0007] The improved pump may further include a boundary seal (54) separating a
wet por-
tion (55) of the second motor from a dry portion (56) of the second motor. The
second motor
may have one portion (58) arranged on one side of the seal, and may have
another portion
(59) arranged on the other side of the seal. The one portion may include a
pemianent magnet
(58), and the other portion may include a coil (59).
[0008] The member may be mounted on the housing.
[0009] In one form, the member may be mounted on the housing by a flexure
member (40).
[0010] The range of member motion may be arcuate, linear or rotational.
[0011] A resilient member (41) may be arranged to act between the housing and
the member
for urging the member to move toward the null position.
[0012] In another form, the improved vane pump (20) may include: a housing
(21); a shaft
(22) having a shaft axis (yi-yi), the shaft being mounted on the housing for
rotation about the
shaft axis; a first motor (23) mounted on the housing and operatively arranged
to selectively
rotate the shaft; a plurality of rotors (24 in Fig. 1; 51 in Fig. 5) mounted
for rotation with the
shaft at spaced locations therealong, each rotor having a plurality of
circumferentially-spaced
slots (26); a plurality of members (28), each member having a surface (57) and
having a
member axis (y2-y2), each member being associated with a respective one of the
rotors and
being movable relative to the shaft axis through a permissible range of motion
(30 in Fig. 1)
which includes portions on either side of a null position; wherein each member
axis is coinci-
dent with the shaft axis when the associated member is in the null position; a
vane (26)
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movably mounted in each rotor slot and having a distal end arranged to
sealingly and wip-
ingly engage the surface of the associated member; the vanes defining with the
associated
rotor and surface a plurality of chambers (33A-33F in Fig. 1; 62A-62F in Fig.
6), the individ-
ual volumes of the chambers varying as a function of the relative position
between the asso-
ciated rotor and surface; the housing having two fluid passageways (34, 34)
operatively ar-
ranged to communicate with two of the chambers for each member as a function
of the angu-
lar position of the rotor relative to the housing; a plurality of second
motors (31) operatively
arranged to selectively move the associated member relative to the shaft axis
through its per-
missible range of motion; wherein movement of each member off null in one
direction along
the range of motion of such member will enable fluid flow in a first direction
between the
ports of such member; and wherein movement of each member off null in the
opposite direc-
tion along the range of motion of such member will enable fluid flow in the
opposite direc-
tion between the ports of such member.
[0013] The members may be stacked at axially-spaced locations along the shaft.
[0014] The fluid output of each member may be controllable independently.
[0015] The improved pump may further include a plurality of boundary seals
(54). Each
boundary seal may separate a wet portion (55) of an associated second motor
from a dry por-
tion (56) of such associated second motor. Each second motor may have one
portion ar-
ranged on one side of the associated seal, and may have another portion
arranged on the other
side of such associated seal. The one portion may include a permanent magnet
(58), and the
other portion may include a coil (59).
[0016] Each member may be mounted on the housing by a flexure member (40).
[0017] The range of motion of each member may be arcuate, linear or
rotational.
[0018] The pump may further include a resilient member (41) acting between the
housing
and each member for urging such member to move toward the null position.
[0019] In a third form, the improved vane pump (20) may include: a housing
(21); a shaft
(22) having a shaft axis (y 1-y1), the shaft being mounted on the housing for
rotation about the
shaft axis; a first motor (23) operatively arranged to selectively rotate the
shaft; a rotor
mounted for rotation with the shaft, the rotor having a plurality of
circumferentially-spaced
slots (26); a member (28) having a surface (29) arranged to face the rotor and
having a mem-
ber axis (y2-y2), the member being movable relative to the shaft axis through
a permissible
range of motion (30) which includes portions ("-1", "+1") on either side of a
null position
("O"); wherein the member axis is coincident with the shaft axis when the
member is in the
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null position; a vane (30) movably mounted in each rotor slot and having a
distal end ar-
ranged to engage the member surface; a second motor (31) operatively arranged
to selectively
move the member relative to the shaft axis through the permissible range of
motion; the
vanes defining with the rotor and surface a plurality of chambers (33A-33F),
the individual
volumes of the chambers varying as a function of the relative position between
the rotor and
surface; the housing having two fluid passageways (34, 34) operatively
arranged to commu-
nicate with two of the chambers as a function of the angular position of the
rotor relative to
the housing; and wherein the direction of flow between the passageways is a
function of the
position of the member axis (y2-y2) relative to the shaft axis (yi-y1).
[0020] The direction of fluid flow between the passageways may be in one
direction when
the member has been moved off-null in one direction along the range of motion,
and may be
in the opposite direction when the member has been moved off-null in the
opposite direction
along the range of motion.
[0021] The pump may further include a boundary seal (54) separating a wet
portion (55) of
the second motor from a dry portion (56) of the second motor. The second motor
may have
one portion arranged on one side of the seal, and may have another portion
arranged on the
other side of the seal. The one portion may include a permanent magnet (58),
and the other
portion may include a coil (59).
[0022] In a fourth form, the improved vane pump (20 in Fig. 1; 50 in Fig. 5)
may include: a
shaft (22) having a shaft axis (yi-y 1), the shaft being mounted for rotation
about the shaft axis;
a first motor (23) operatively arranged to selectively rotate the shaft about
the shaft axis; a
rotor (24) mounted for rotation with the shaft, the rotor having a plurality
of circumferen-
tially-spaced slots (26); a member (28) having a surface (29) and having a
member axis (y2-
y2), the member being movable relative to the shaft axis through a peanissible
range of mo-
tion (30) which includes portions (i.e., positions "-1" and "+1",
respectively) on either side of
a null position (i.e., position "O"); wherein the member axis is coincident
with the shaft axis
when the member is in the null position; a vane (32) movably mounted in each
rotor slot and
having a distal end arranged to sealingly and wipingly engage the member
surface; the vanes
defining with the rotor and surface a plurality of chambers (33A-33F), the
individual volumes
of the chambers varying as a function of the relative position between the
rotor and surface; a
second motor operatively arranged to selectively move the member relative to
the shaft axis
through the permissible range of motion; and a boundary seal (54) separating a
wet portion
(55) of the second motor from a dry portion (56) of the second motor; and
wherein the second
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motor has one portion (58) arranged on one side of the seal and has another
portion (59) ar-
ranged on the other side of the seal.
[0023] The one portion may include a permanent magnet (58), and the other
portion may
include a coil (59).
[0024] Also provided is an improved method of operating a vane pump (20) that
includes a
housing (21), a rotor (24) having a rotor axis (yi-y1) and being rotatably
mounted on the hous-
ing, the rotor having a plurality of circumferentially-spaced slots (26); a
member (28) having
a surface (29) arranged to face the rotor and having a member axis (y2-y2),
the member being
movable relative to the rotor axis through a permissible range of motion (30);
wherein the
member axis (y2-y2) is coincident with the rotor axis (yi-yi) when the member
is in the null
position; a vane (32) movably mounted in each rotor slot and having a distal
end arranged to
engage the member surface; the vanes defining with the rotor and surface a
plurality of
chambers (33A-33F), the individual volumes of the chambers varying as a
function of the
relative position between the rotor and surface; comprising the steps of:
rotating the rotor in
one angular direction about the rotor axis; selectively moving the member
relative to the ro-
tor; and varying the direction of fluid flow between the ports as by varying
the position be-
tween the rotor and member axes.
[0025] The method may further include the step of varying the magnitude of the
fluid flow
between the ports by varying the position between the rotor and member axes.
[0026] The position between the rotor and member axes may be varied by moving
the
member relative to the rotor.
[0027] Accordingly, the general object of the invention is to provide an
improved vane
pump.
[0028] Another object is to provide an improved vane pump having a plurality
of stackable
pump elements.
[0029] Another object is to provide an improved vane pump having a plurality
of stackable
pump elements that may be controlled independently of one another.
[0030] Still another object is to provide an improved method of operating a
vane pump.
[0031] These and other objects and advantages will become apparent from the
foregoing
and ongoing written specification, the drawings and the appended claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Fig. 1 is a fragmentary schematic vertical sectional view of a first
form of an im-
proved vane pump.
[0033] Fig. 2 is fragmentary schematic horizontal sectional view thereof,
taken generally on
line 2-2 of Fig. 1.
[0034] Fig. 3 is a fragmentary schematic horizontal sectional view through a
second form of
the improved vane pump, this view showing the member as being movably mounted
on the
housing by means of a flexure member, this view showing the member as being in
a right-
wardly-displaced off-null position relative to the rotor.
[0035] Fig. 4 is a fragmentary schematic horizontal sectional view of another
form of the
improved vane pump, generally similar to Fig. 3, but shows the member as
constrained for
linear motion within bearings, and shows the member as being in a rightwardly-
displaced off-
null position.
[0036] Fig. 5 is a fragmentary schematic vertical sectional view showing a
plurality of ro-
tors and members being stacked at axially-spaced locations along the shaft.
[0037] Fig. 6 is a fragmentary schematic horizontal sectional view, taken
generally on line
6-6 of Fig. 5, showing one rotor within its associated member.
[0038] Fig. 7 is a schematic view of a vane pump, generally similar to Fig. 4,
showing the
member as being in its null position relative to the rotor.
[0039] Fig. 8A is a view generally similar to Fig. 7, showing the member as
having been
moved rightwardly off-null and showing chamber 71A as having been filled with
fluid from
fluid port CI.
[0040] Fig. 8B is a view similar to Fig. 8A, but shows the rotor as having
been rotated in a
clockwise direction through an arc of about 600 from the position shown in
Fig. 8A.
[0041] Fig. 8C is a view similar to Fig. 8B, but shows the rotor as having
been further ro-
tated in a clockwise direction through an arc of about 60 from the position
shown in Fig. 8B,
and showing chamber 71A as being aligned with fluid port C2.
[0042] Fig. 9A is a view generally similar to Fig. 7, showing the member as
having been
moved leftwardly off-null and showing chamber 71A as being aligned with fluid
port C2.
[0043] Fig. 9B is a view similar to Fig. 9A, but shows the rotor as having
been rotated in a
clockwise direction through an arc of about 60 from the position shown in
Fig. 9A.
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[0044] Fig. 9C is a view similar to Fig. 9B, but shows the rotor as having
been further ro-
tated in a clockwise direction through an arc of about 60 from the position
shown in Fig. 9B,
and showing chamber 71A as being aligned with fluid port C1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] At the outset, it should be clearly understood that like reference
numerals are in-
tended to identify the same structural elements, portions or surfaces
consistently throughout
the several drawing figures, as such elements, portions or surfaces may be
further described
or explained by the entire written specification, of which this detailed
description is an inte-
gral part. Unless otherwise indicated, the drawings are intended to be read
(e.g., cross-
hatching, arrangement of parts, proportion, degree, etc.) together with the
specification, and
are to be considered a portion of the entire written description of this
invention. As used in
the following description, the terms "horizontal", "vertical", "left",
"right", "up" and "down",
as well as adjectival and adverbial derivatives thereof (e.g., "horizontally",
"rightwardly",
"upwardly", etc.), simply refer to the orientation of the illustrated
structure as the particular
drawing figure faces the reader. Similarly, the terms "inwardly" and
"outwardly" generally
refer to the orientation of a surface relative to its axis of elongation, or
axis of rotation, as ap-
propriate.
[0046] Referring now to the drawings, the present invention broadly provides
improved
vane pumps, and improved methods of operating same.
[0047] In Figs. 1 and 2, a first form of the improved vane pump is generally
indicated at 20.
This pump is shown as broadly as including an annular housing 21, a shaft 22
having a verti-
cal shaft axis a
first motor 23 mounted on the housing and operatively arranged to se-
lectively rotate the shaft about axis and
a rotor 24 mounted on the lower end of the
shaft for rotation therewith.
[0048] The rotor is shown as being a vertically-elongated cylindrical member
having an out-
wardly-facing vertical cylindrical surface 25 of radius R1. A plurality of
circumferentially-
spaced radial slots, severally indicated at 26, extend into the rotor from
surface 25. Motor 23
is arranged to rotate rotor 24 at the appropriate angular speed in either
angular direction, as
desired, relative to the housing. However, unlike prior art vane pumps, the
direction and
speed of rotor rotation does not have to be changed or modified to reverse the
direction of
fluid flow between fluid ports C1, C2, as discussed infra.
[0049] An annular member, generally indicated at 28, surrounds the rotor. This
member has
an inwardly-facing vertical cylindrical surface 29 generated about a member
axis y2-y2. In
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Fig. 1, the member axis y2-y2 is shown as being coincident with the rotor axis
yi-y 1. Hence, in
Fig. 2, these coincident axes are indicated at y]/y2 - y1/y2. In this
embodiment, the member is
movable relative to the shaft axis through a horizontal permissible range of
motion, which
includes portions on either side of (i.e., to the left and right of) a null
position. This range of
motion is schematically indicated at 30 in Figs. 1 and 2. The null position is
indicated by the
center reference "0", and the portions to the left and right thereof are
indicated by "-1" and
"+1", respectively. Thus, the permissible range of motion of the member
relative to the stator
is from "-1" to "+111, and the null position "0" is centered therebetween.
However, this need
not invariably occur. The extreme limits of the range of motion, "4" and "+1",
respectively,
may be equally distant from null position "0", or not. In Figs. 1 and 2, the
member is shown
as being in its null position such that axes yi-yi and y2-y2 are coincident.
The member can be
moved in a horizontal direction, either leftwardly or rightwardly from the
position shown in
Fig. 2, by a motor 31.
[0050] A vane 32 is shown as being movably mounted in each rotor slot and as
having a dis-
tal end arranged to sealingly and wipingly engage the member surface 29. The
vanes define
with the rotor and the surface a plurality of circumferentially-spaced
chambers. In the em-
bodiment shown, there are six vanes that subdivide the space between the rotor
and the mem-
ber into six chambers, severally indicated at 33 and individually identified
with the suffix A,
B, C, D, E and F. These vanes may be spring-biased into engagement with
surface 29, or
they may be moved outwardly by centrifugal force when the rotor rotates and/or
may be
fluid-biased into engagement with surface 29.
[0051] In Figs. 1 and 2, the housing is shown as having two passageways,
severally indi-
cated at 34, that communicate with an opposite two of the chambers as a
function of the an-
gular position of the rotor of the housing. However, in another embodiment the
passageways
could communicate elsewhere with the chambers. For example, the passageways
might sim-
ply communicate with the end wall of the chambers. Other forms may have more
than two
passageways. In the schematic embodiment shown in Figs. 1 and 2, movement of
the mem-
ber off-null in one direction, either leftwardly or rightwardly, along the
horizontal range of
motion will enable fluid flow in a first direction between the ports Ci, C2
(e.g., from CI to
C2), while movement of the member off-null in the opposite direction along the
range of mo-
tion will enable fluid flow in the opposite direction between these ports
(e.g., from C2 to C1).
Thus, the direction of fluid flow between ports CI, C2 may be reversed by
selectively moving
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the member along the permissible range of motion, without affecting either the
speed or di-
rection of rotor rotation.
[0052] Fig. 3 is a schematic view of another form of the inventive vane pump,
generally in-
dicated at 35. This embodiment also has a specially-configured hollow housing,
generally
indicated at 36, with a member 38 therewithin surrounding a rotor 39, as
previously de-
scribed. Here again, the distal ends of vanes 32 sealingly and wipingly engage
the inwardly-
facing surface 29 of the member. In this embodiment, member 38 is supported on
the hous-
ing by means of a flexure member, generally indicated at 40. The lower end of
member 38 is
supported by a spring-biased telescopic linkage or resilient member, generally
indicated at
41. This linkage includes an upper portion 42 pivotally connected to member
38, and a lower
portion 43 pivotally connected to the housing and telescopically received
within the upper
portion. A coil spring 44 acts between the two linkage portions, and
continually urges the
pivotal connection between the linkage and the member to move downwardly. This
tends to
remove all backlash from the linkage holding suspended member 38, and,
further, continu-
ously urges the off-null displaced member to move back toward a null position.
[0053] In this arrangement, a second motor 31 is shown as being operatively
arranged to
selectively move member 38 either leftwardly or rightwardly off null, as
desired relative to
the shaft axis through a horizontal permissible range of motion which includes
portions on
either side (i.e., to the left and right of) of a null position "0". Unlike
the first embodiment in
which the member was mounted for pure linear motion relative to the housing,
in the em-
bodiment shown in Fig. 3, member 38 is mounted for arcuate swinging movement
about
some effective pivot point along flexure member 40. However, because the
extent of move-
ment of member 38 relative to the rotor is small in relation to the distance
between the effec-
tive pivot on flexure member 40 and the member axis, the permissible range of
motion is
again schematically indicated by a horizontal line 30 in Fig. 3. The null
position is indicated
by the reference "0", and the portions to the left and right thereof are
indicated by "4" and
"+1", respectively. Thus, the range of motion of the member relative to the
stator is approxi-
mated by the distance between "-1" to "+1", with the null position "0" is
centered therebe-
tween. The member can be moved by a motor 34 either leftwardly or rightwardly
from the
position shown. In Fig. 3, member 38 is shown as having been shifted
rightwardly relative to
the rotor from its null position (i.e., from null position "0" to rightwardly-
shifted position
"+1"). This off-null displacement of the member causes the volumes of the vane
chambers to
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vary as the rotor rotates in one angular direction. This causes fluid to be
directed from port
CI to port C2, or vice versa, depending on the direction of rotor rotation.
[0054] Fig. 4 is a schematic view of another form of the improved vane pump
having a
member 38 arranged to be moved relative to a rotor 39. However, in this
arrangement, the
member is not mounted for pivotal or swinging arcuate movement relative to the
housing.
Rather, the member is constrained for linear sliding motion, both leftwardly
and rightwardly,
along a horizontal permissible range of movement defined by bearings,
severally indicated at
49. Thus, this arrangement is generally similar to the first embodiment
insofar as movement
of the member relative to the rotor is concerned.
[0055] Fig. 5 is a schematic view of another form of vane pump, generally
indicated at 50.
This embodiment is shown as having a plurality of rotors, severally indicated
at 51, and
members, severally indicated at 52, mounted at longitudinally-spaced locations
along a verti-
cally-disposed shaft 53. Thus, the various vane pumps are "stacked" at various
locations
along the shaft. The shaft is arranged to be rotated about shaft axis yi-yi by
a first motor (not
shown), as previously described. However, in this arrangement the various
members 52 are
mounted on bearings 54 for rotation relative to a housing 55. The positions of
the various
vane members may be controlled by individual second motors 31, again as
previously de-
scribed. Each vane pump is arranged to produce its own individual fluidic
output as a func-
tion of the position of the associated member relative to its associated
rotor. The several vane
pumps are operable independently of one another. They do share the fact that
their respective
rotors rotate about common shaft 53. However, the positions of the various
members are
controllable independently of one another so that each vane pump has its own
independently-
controllable fluidic output. However, unlike the previously-described forms,
in this embodi-
ment, each second motor (not shown) is operatively arranged to rotate its
associate member
relative to the shaft axis yi-yi to vary the position of the member axis
relative to the shaft
axis. A thin integrally-formed web-like annular boundary seal 54 separates a
wet portion 55
of the second motor from a dry portion 56 of second motor 31. The second motor
has one
portion 58 arranged on one side of the seal and has another portion 59
arranged on the other
side of the seal. The one portion may include a permanent magnet 58, and the
other portion
may include a coil 59.
[0056] Fig. 6 is a schematic view of a rotor and member of one vane pump,
taken generally
on line 6-6 of Fig. 5. This view is generally similar to Fig. 2, but shows the
member surface
29 as being non-concentrically arranged within the member outer surface 56.
Surface 56 is of
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radius R3, and is generated about member axis y3-y3. Hence, rotation of the
member relative
to the housing (shown in Fig. 5) about member outer surface axis y3-y3 will
cause non-
concentric rotation of the member inner surface 29 relative to the rotor. This
relative rotation
between the member and housing will vary the volumes of chambers 62A-62F to
vary the
magnitude and direction of flow through the valve.
[0057] Fig. 7 is a schematic view of a portion of one vane pump, generally
indicated at 65,
showing a member 66 as being in its null position relative to a rotor 68. Vane
pump 65 is
generally similar to the vane pump shown in Fig. 4. Here again, there are six
vanes, severally
indicated at 69, mounted in slots in the rotor. Each of these vanes has a
distal end that seal-
ingly and wipingly engages an inwardly-facing surface 70 on the member. In
Fig. 7, the
member axis y2-y2 is shown as being coincident with the rotor axis The
member is
shown as having two fluid connections that communicate with two different vane
chambers.
The first is labeled C1 and the second is labeled C2.
[0058] Fig. 8A-c are a series of views, generally similar to Fig. 7, but
showing the member
as having been moved off-null to the right. In Fig. 8A, fluid from port Ci is
shown as enter-
ing vane chamber 71A. In Fig. 8B, the rotor is shown as having rotated vane
chamber 71A
from a position that communicates with fluid inlet C1 in a clockwise direction
through an arc-
distance of 60 to an intermediate position. In Fig. 8C, the rotor is shown as
having been fur-
ther rotated in a clockwise direction relative to the member by an additional
arc-distance of
60 such that vane chamber 71A has been rotated to a position at which it
communicates with
fluid outlet C2. In Figs. 8A-8C, a volume of fluid is shown as entering vane
chamber 71A
and being progressively conveyed in a clockwise direction relative to the
member. Ulti-
mately, the fluid is discharged through outlet C2.
[0059] Figs. 9A-9C are a series of a view that depict the member as having
been shifted left-
wardly off-null from the position shown in Fig. 7. Here again, fluid entering
vane chamber
71A communicating with fluid inlet C2 is progressively conveyed as the rotor
rotates in a
clockwise direction within the member, and is ultimately discharged at fluid
port CI.
[0060] Therefore, the present invention broadly provides an improved vane pump
that
broadly includes a housing, a shaft, a first motor, a rotor mounted on the
shaft for rotation
therewith, and a member having a surface and a member axis. The member axis is
defined as
being that location on the member when the member is in a null position
relative to the rotor.
Vanes are mounted on the rotor, and have distal ends arranged to engage the
member surface.
These vanes define with the rotor and surface a plurality of fluid chambers,
the individual
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CA 02890682 2015-05-07
WO 2014/077835 PCT/US2012/065608
volumes of which vary as a function of relative position between the rotor and
the member
surface. The housing also has two fluid passageways that are operatively
arranged to com-
municate with two of the chambers as a function of the angular position of the
rotor relative
to the housing. A second motor is operatively arranged to selectively move the
member rela-
tive to the shaft axis through a permissible range of motion. Movement of the
member off-
null in one direction along the range of motion will enable fluid flow in the
first direction be-
tween the ports, and movement of the member off-null in the opposite direction
along the
range of motion will enable fluid flow in the opposite direction between the
ports.
[0061] One unique feature of the invention is that the direction of fluid flow
through the
vane pump may be changed by simply moving the member relative to the rotor,
but without
changing the direction or speed of rotation of the rotor about the shaft axis.
In other words,
the direction of fluid flow through the vane pump may be changed without
adversely affect-
ing the inertia of the moving rotor.
[0062] The present invention contemplates that may changes and modifications
may be
made. The shape and configuration of the rotor may be readily changed or
modified. In the
embodiment shown, the rotor has six slots, each of which is provided with a
vane. This sub-
divides the space between the rotor and the member into six vane chambers.
However, the
size, configuration and shape of the rotor, as well as the number of vane
slots, may be
changed. The vanes may be moveable outwardly by centrifugal force.
Alternatively, they
may be spring-biased, or may be pushed outwardly by means of a fluid pressure.
[0063] Similarly, the shape and configuration of the member may be changed. In
the em-
bodiment shown, the member is shown as having a cylindrical inwardly-facing
surface
against which the distal ends of the vanes act. However, the invention is not
limited to a
member having an inwardly-facing cylindrical surface. Indeed, the member
surface might be
cylindrical, or might have some other shape, as desired. The member may be
movable along
a linear path, an arcuate path, or a rotational path. The arrangement and
shape of the member
and housing ports may be readily changed or modified as desired.
[0064] Therefore, while several forms of the improved vane pumps have been
shown and
described, and several modifications thereof discussed, persons skilled in
this art will readily
appreciate that various additional changes and modifications may be made
without departing
from the spirit of the invention, as defined and differentiated by the
following claims.
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