U.S. patent application number 17/275466 was filed with the patent office on 2022-02-17 for vane pump device.
This patent application is currently assigned to Hitachi Astemo, Ltd.. The applicant listed for this patent is Hitachi Astemo, Ltd.. Invention is credited to Toshio NISHIKAWA, Naoya TAGA.
Application Number | 20220049698 17/275466 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-17 |
United States Patent
Application |
20220049698 |
Kind Code |
A1 |
NISHIKAWA; Toshio ; et
al. |
February 17, 2022 |
VANE PUMP DEVICE
Abstract
A vane pump includes: a rotor configured to rotate under
rotational force from a rotary shaft while supporting multiple
vanes and including a curved surface portion with an arc shape
centered on the rotary shaft and a rotor recess depressed from the
curved surface portion toward a rotation center; a cam ring
disposed so as to surround the rotor and including an inner
peripheral surface facing the curved surface portion of the rotor;
and an inner plate disposed on one end of the cam ring in an axial
direction of the rotary shaft so as to cover an opening of the cam
ring and including a suction inner recess depressed toward the
rotation center relative to the curved surface portion of the
rotor.
Inventors: |
NISHIKAWA; Toshio;
(Hitachinaka-shi, JP) ; TAGA; Naoya;
(Hitachinaka-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hitachi Astemo, Ltd. |
Hitachinaka-shi |
|
JP |
|
|
Assignee: |
Hitachi Astemo, Ltd.
Hitachinaka-shi
JP
|
Appl. No.: |
17/275466 |
Filed: |
October 22, 2018 |
PCT Filed: |
October 22, 2018 |
PCT NO: |
PCT/JP2018/039212 |
371 Date: |
March 11, 2021 |
International
Class: |
F04C 2/344 20060101
F04C002/344 |
Claims
1. A vane pump device comprising: a rotor configured to rotate
under rotational force from a rotary shaft while supporting a
plurality of vanes, the rotor including a curved surface portion
with an arc shape centered on the rotary shaft, the rotor including
a first recess depressed from the curved surface portion toward a
rotation center; a cam ring disposed so as to surround the rotor,
the cam ring including an inner peripheral surface facing the
curved surface portion of the rotor; and a one side member disposed
on one end of the cam ring in an axial direction of the rotary
shaft so as to cover an opening of the cam ring, the one side
member including a second recess depressed toward the rotation
center relative to the curved surface portion of the rotor.
2. The vane pump device according to claim 1, wherein the one side
member includes an inner portion that constitutes a portion of a
suction port on a side thereof closer to the rotation center, the
suction port being configured to suction a working fluid into a
pump chamber defined by an outer peripheral surface of the rotor,
the inner peripheral surface of the cam ring, and two adjacent
vanes of the plurality of vanes, and the second recess is a portion
that is a part of the inner portion and depressed toward the
rotation center.
3. The vane pump device according to claim 2, wherein the inner
portion of the one side member comprises a portion that is
contoured to a shape of the curved surface portion of the rotor,
and a portion of the inner portion between the portion contoured to
the shape of the curved surface portion and the second recess is
contoured to a shape of the inner peripheral surface of the cam
ring.
4. The vane pump device according to claim 2, wherein the second
recess of the one side member is formed at a downstream portion of
the inner portion in a circumferential direction.
5. The vane pump device according to claim 2, wherein the second
recess of the one side member is formed substantially at a center
of the inner portion in a circumferential direction.
6. The vane pump device according to claim 1, wherein the second
recess of the one side member is formed over an entire region of a
portion of a suction port on a side thereof closer to the rotation
center, the suction port being configured to suction a working
fluid into a pump chamber defined by an outer peripheral surface of
the rotor, the inner peripheral surface of the cam ring, and two
adjacent vanes of the plurality of vanes.
7. The vane pump device according to claim 1, wherein the cam ring
includes a third recess depressed in an axial direction of the
rotary shaft from a mating surface of the cam ring for mating with
the one side member, the third recess being configured to
constitute a suction port, the suction port being configured to
constitute a suction path through which a working fluid is
suctioned into a pump chamber defined by an outer peripheral
surface of the rotor, the inner peripheral surface of the cam ring,
and two adjacent vanes of the plurality of vanes, and the first
recess of the rotor is formed at a portion of the rotor facing the
third recess of the cam ring.
8. The vane pump device according to claim 7, wherein a size of the
first recess of the rotor in the axial direction of the rotary
shaft is smaller than a size of the third recess of the cam ring in
the axial direction of the rotary shaft.
9. The vane pump device according to claim 1, wherein the one side
member includes an inner portion that constitutes a portion of a
discharge port on a side thereof closer to the rotation center, the
discharge port being configured to discharge a working fluid from a
pump chamber defined by an outer peripheral surface of the rotor,
the inner peripheral surface of the cam ring, and two adjacent
vanes of the plurality of vanes, and the second recess is a portion
that is a part of the inner portion and depressed toward the
rotation center.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a U.S. National Phase Application under
35 U.S.C. .sctn. 371 of International Patent Application No.
PCT/JP2018/039212, filed October 22, 2018, which is incorporated
herein by reference in its entirety. The International Application
was published in Japanese on Apr. 30, 2020 as International
Publication No. WO/2020/084666 under PCT Article 21(2).
FIELD OF THE INVENTION
[0002] The present invention relates to a vane pump device.
BACKGROUND OF THE INVENTION
[0003] Japanese Patent Application Laid-Open Publication No.
2013-050067 discloses a vane pump including: a rotor which is
connected to a rotating shaft pivoted to an inner portion of a
housing so as to rotate; a cam ring which is arranged in such a
manner as to surround the rotor in the inner portion of the
housing; a plurality of vanes which are slidably arranged in a
plurality of vane grooves provided in a radial direction of the
rotor; a plurality of pump chambers which are defined by the
adjacent vanes around the rotor; and a plurality of discharge ports
corresponding to the pump chambers carrying out a compression
stroke, which are provided to be opposed in a diametrical direction
of the rotor. In the vane pump disclosed in Japanese Patent
Application Laid-Open Publication No. 2013-050067, the rotor is
formed with recesses depressed from an outer peripheral surface
thereof toward a rotation center.
CITATION LIST
Patent Literature
[0004] Patent Literature 1: Japanese Patent Application Laid-Open
Publication No. 2013-050067
Technical Problem
[0005] To reduce viscosity of oil used as a working fluid of a vane
pump, air bubbles (air) contained in the oil have been increasing.
Suctioning of oil containing a large amount of air bubbles may lead
to decrease in suction/discharge efficiency, fluctuation in
discharge pressure, and aggravation of noise, for example. To
suppress the decrease in suction/discharge efficiency and the like
due to increase of air bubbles contained in the oil, one may
conceive of reducing the capacity of pump chambers to thereby
reduce an absolute amount of oil suctioned into the pump chambers.
To achieve this, one may conceive of forming an outer peripheral
surface of a rotor into an arc shape that is centered on the
rotation center of the rotor. However, merely changing the outer
peripheral surface of the rotor into an arc shape centered on the
rotation center of the rotor to reduce the capacity of the pump
chambers may lead to reduced suction efficiency and thus reduced
pump performance.
[0006] An object of the present invention is to provide a vane pump
device that can suppress decrease in pump performance while
reducing the suctioned amount of air bubbles contained in a working
fluid.
SUMMARY OF THE INVENTION
Solution to Problem
[0007] With the above object in view, an aspect of the present
invention is a vane pump device including: a rotor configured to
rotate under rotational force from a rotary shaft while supporting
a plurality of vanes, the rotor including a curved surface portion
with an arc shape centered on the rotary shaft, the rotor including
a first recess depressed from the curved surface portion toward a
rotation center; a cam ring disposed so as to surround the rotor,
the cam ring including an inner peripheral surface facing the
curved surface portion of the rotor; and a one side member disposed
on one end of the cam ring in an axial direction of the rotary
shaft so as to cover an opening of the cam ring, the one side
member including a second recess depressed toward the rotation
center relative to the curved surface portion of the rotor.
Advantageous Effects of Invention
[0008] The present invention can provide a vane pump device that
can suppress decrease in pump performance while reducing the
suctioned amount of air bubbles contained in a working fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of some of components of a vane
pump as viewed from a cover side.
[0010] FIG. 2 is a perspective view of some of components of the
vane pump as viewed from a case side.
[0011] FIG. 3 is a sectional view depicting a first oil channel in
the vane pump.
[0012] FIG. 4 is a sectional view depicting a second oil channel in
the vane pump.
[0013] FIG. 5 depicts a rotor, vanes, and a cam ring as viewed in
one direction and in the other direction along a rotational axis
direction.
[0014] FIG. 6 depicts a distance from a rotation center to a cam
ring inner peripheral surface of the cam ring at each rotational
angle.
[0015] FIG. 7 depicts an inner plate as viewed in the one direction
and in the other direction along the rotational axis direction.
[0016] FIG. 8 depicts an outer plate as viewed in the other
direction and in the one direction along the rotational axis
direction.
[0017] FIG. 9 depicts a case as viewed in the one direction along
the rotational axis direction.
[0018] FIG. 10 depicts the cam ring and the inner plate as viewed
in the one direction.
[0019] FIG. 11 is a sectional view taken along a line XI-XI in FIG.
10.
[0020] FIG. 12 is a perspective view of the rotor, the multiple
vanes, the cam ring, and the outer plate.
[0021] FIG. 13 depicts a schematic configuration of a suction inner
portion of a vane pump of the second embodiment.
[0022] FIG. 14 depicts a schematic configuration of a suction inner
portion of a vane pump of the third embodiment.
[0023] FIG. 15 depicts a schematic configuration of a suction inner
portion of a vane pump of the fourth embodiment.
[0024] FIG. 16 depicts an inner plate of the fifth embodiment as
viewed in the one direction and in the other direction along the
rotational axis direction.
[0025] FIG. 17 depicts an outer plate of the fifth embodiment as
viewed in the other direction and in the one direction along the
rotational axis direction.
[0026] FIG. 18 depicts the cam ring and the inner plate as viewed
in the one direction.
[0027] FIG. 19 depicts a modification of a rotor recess of the
rotor.
[0028] FIG. 20 depicts a modification of a curved surface portion
of the rotor.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Embodiments of the present invention will be described below
in detail with reference to the attached drawings.
First Embodiment
[0030] FIG. 1 is a perspective view of some of components of a vane
pump device 1 (hereinafter referred to as a "vane pump 1") of the
embodiment as viewed from a cover 120 side.
[0031] FIG. 2 is a perspective view of some of components of the
vane pump 1 as viewed from a case 110 side.
[0032] FIG. 3 is a sectional view depicting a first oil channel in
the vane pump 1. FIG. 3 is also a sectional view taken along a line
III-III in FIG. 5.
[0033] FIG. 4 is a sectional view depicting a second oil channel in
the vane pump 1. FIG. 4 is also a sectional view taken along a line
IV-IV in FIG. 5.
[0034] The vane pump 1 is a pump that is driven by, for example,
power from an engine of a vehicle and supplies oil, which is an
example of the working fluid, to apparatuses such as a hydraulic
continuously variable transmission and a hydraulic power steering
apparatus.
[0035] Also, the vane pump 1 suctions oil from a single suction
inlet 116 and discharges it from two different discharge outlets of
a first discharge outlet 117 and a second discharge outlet 118.
Pressures of oil discharged from the first discharge outlet 117 and
the second discharge outlet 118 may be either the same as or
different from each other. More specifically, the vane pump 1
suctions oil from the suction inlet 116 into pump chambers through
a first suction port 2 (see FIG. 3) and increases pressure of the
oil in the pump chambers before discharging it to the outside from
the first discharge outlet 117 through a first discharge port 4
(see FIG. 3). Additionally, the vane pump 1 suctions oil from the
suction inlet 116 into the pump chambers through a second suction
port 3 (see FIG. 4) and increases pressure of the oil in the pump
chambers before discharging it to the outside from the second
discharge outlet 118 through a second discharge port 5 (see FIG.
4). The first suction port 2, the second suction port 3, the first
discharge port 4, and the second discharge port 5 are portions
confronting (facing) the pump chambers.
[0036] The vane pump 1 includes a rotary shaft 10 that rotates
under driving force from an engine of a vehicle or a motor, a rotor
20 that rotates along with the rotary shaft 10, multiple vanes 30
that are embedded in respective grooves formed in the rotor 20, and
a cam ring 40 surrounding outer peripheries of the rotor 20 and the
vanes 30.
[0037] The vane pump 1 further includes an inner plate 50 as an
example of the one side member disposed at one end side of the
rotary shaft 10 relative to the cam ring 40, and an outer plate 60
as an example of the other side member disposed at the other end
side of the rotary shaft 10 relative to the cam ring 40.
[0038] The vane pump 1 further includes a housing 100 accommodating
the rotor 20, the multiple vanes 30, the cam ring 40, the inner
plate 50, and the outer plate 60. The housing 100 includes a
closed-end cylindrical case 110 and a cover 120 closing an opening
of the case 110.
<Configuration of the Rotary Shaft 10>
[0039] The rotary shaft 10 is rotatably supported by a case-side
bearing 111 (described later) provided to the case 110 and a
cover-side bearing 121 (described later) provided to the cover 120.
The rotary shaft 10 is formed on its outer peripheral surface with
a spline 11 and is connected to the rotor 20 via the spline 11. In
the present embodiment, the rotary shaft 10 rotates under driving
force of a driving source disposed outside of the vane pump 1, such
as an engine of the vehicle, and rotates the rotor 20 via the
spline 11.
[0040] In the vane pump 1 of the present embodiment, the rotary
shaft 10 (the rotor 20) is configured to rotate in a clockwise
direction in FIG. 1.
<Configuration of the Rotor 20>
[0041] FIG. 5 depicts the rotor 20, the vanes 30, and the cam ring
40 as viewed in one direction and in the other direction along the
rotational axis direction.
[0042] The rotor 20 is a generally cylindrical member. The rotor 20
is formed on its inner peripheral surface with a spline 21 to be
engaged with the spline 11 (see FIG. 1) of the rotary shaft 10. The
rotor 20 includes on its outer periphery with curved surface
portions 22 of an arc shape centered on a rotation center C of the
rotary shaft 10. The rotor 20 is also formed on its outer periphery
with vane grooves 23 depressed from the outer peripheral surface of
the rotor 20 toward the rotation center C to accommodate the
respective vanes 30. Multiple (ten in the present embodiment) vane
grooves 23 are formed (radially) at equal intervals in the
circumferential direction. The rotor 20 is also formed on its outer
periphery with rotor recesses 24, which is an example of the first
recess, depressed from the respective curved surface portions 22
toward the rotation center C.
[0043] Each curved surface portion 22 is formed between two
adjacent vane grooves 23.
[0044] Each vane groove 23 is a groove that opens in the outer
peripheral surface of the rotor 20 and also in both end surfaces of
the rotor 20 in the rotational axis direction of the rotary shaft
10. When viewed in the rotational axis direction, as shown in
FIG.5, the vane groove 23 has, on its outer periphery side, a
rectangular shape whose longitudinal direction coincides with a
radial direction and has, on its side closer to the rotation center
C, a circular shape whose diameter is longer than a length of the
rectangular shape in a transverse direction. In other words, the
vane groove 23 has a cuboid groove 231 formed in a cuboid shape on
its outer periphery side, and a columnar groove 232, which is an
example of a center-side space, formed in a columnar shape on its
side closer to the rotation center C.
[0045] The rotor recesses 24 are formed at respective ends of the
rotor 20 in the rotational axis direction. Each rotor recess 24 is
formed at the center of the corresponding curved surface portion 22
in the circumferential direction. A shape of the rotor recess 24 in
the rotational axis direction is a chamfered shape such that the
rotor recess 24 gradually approaches the rotation center C as it
goes from the center side to the end side in the rotational axis
direction.
<Configuration of the Vane 30>
[0046] Each vane 30 is a cuboid member and embedded into each one
of the vane grooves 23 of the rotor 20. A length of the vane 30 in
the radial direction is shorter than a length of the vane groove 23
in the radial direction, and the vane 30 has a narrower width than
that of the vane groove 23. The vane 30 is held in the vane groove
23 such that the vane 30 can move in the radial direction.
<Configuration of the Cam Ring 40>
[0047] The cam ring 40 is a generally cylindrical member and
includes a cam ring outer peripheral surface 41, a cam ring inner
peripheral surface 42, an inner end surface 43 facing the inner
plate 50 in the rotational axis direction, and an outer end surface
44 facing the outer plate 60 in the rotational axis direction.
[0048] When viewed in the rotational axis direction, the cam ring
outer peripheral surface 41 has a substantially circular shape, in
which a distance from the rotation center C to the cam ring outer
peripheral surface 41 is substantially constant over the entire
circumference thereof (except for a portion thereof), as shown in
FIG. 5.
[0049] FIG. 6 depicts a distance L from the rotation center C to
the cam ring inner peripheral surface 42 of the cam ring 40 at each
rotational angle.
[0050] When viewed in the rotational axis direction, the cam ring
inner peripheral surface 42 of the cam ring 40 is formed to have
two heights in the distance L (i.e., the amount of protrusion of
the vane 30 from the vane groove 23) from the rotation center C
(see FIG. 5) at each rotational angle. That is, when a positive
vertical axis in the view in the other direction in FIG. 5 is
assumed to be at zero degrees, the distance L from the rotation
center C gradually increases in an area between about 20 and 90
degrees in a counterclockwise direction and then gradually
decreases in an area between about 90 and 160 degrees to thereby
form a first height 42a, and gradually increases in an area between
about 200 and 270 degrees and then gradually decreases in an area
between about 270 and 340 degrees to thereby form a second height
42b. The two heights are of the same in the cam ring 40 of the
present embodiment.
[0051] As shown in FIG. 5, the cam ring 40 includes multiple inner
recesses 430 depressed from the inner end surface 43 and multiple
outer recesses 440 depressed from the outer end surface 44.
[0052] As shown in FIG. 5, the inner recesses 430 include a first
suction recess 431 constituting the first suction port 2, a second
suction recess 432 constituting the second suction port 3, a first
discharge recess 433 constituting the first discharge port 4, and a
second discharge recess 434 constituting the second discharge port
5. When viewed in the rotational axis direction, the first suction
recess 431 and the second suction recess 432 are formed to be
point-symmetrical to each other about the rotation center C, and
the first discharge recess 433 and the second discharge recess 434
are formed to be point-symmetrical to each other about the rotation
center C. In the radial direction, the first suction recess 431 and
the second suction recess 432 are depressed from the inner end
surface 43 over the entire region thereof, and in the
circumferential direction, the first suction recess 431 and the
second suction recess 432 are depressed from the inner end surface
43 over a predetermined angular range. In the radial direction, the
first discharge recess 433 and the second discharge recess 434 are
depressed from the inner end surface 43 over a predetermined region
thereof that extends from the cam ring inner peripheral surface 42
to some point toward the cam ring outer peripheral surface 41, and
in the circumferential direction, the first discharge recess 433
and the second discharge recess 434 are depressed from the inner
end surface 43 over a predetermined angular range. [0019]
[0053] As shown in the view in the one direction in FIG. 5, the
outer recesses 440 include a first suction recess 441 constituting
the first suction port 2, a second suction recess 442 constituting
the second suction port 3, a first discharge recess 443
constituting the first discharge port 4, and a second discharge
recess 444 constituting the second discharge port 5. When viewed in
the rotational axis direction, the first suction recess 441 and the
second suction recess 442 are formed to be point-symmetrical to
each other about the rotation center C, and the first discharge
recess 443 and the second discharge recess 444 are formed to be
point-symmetrical to each other about the rotation center C. In the
radial direction, the first suction recess 441 and the second
suction recess 442 are depressed from the outer end surface 44 over
the entire region thereof, and in the circumferential direction,
the first suction recess 441 and the second suction recess 442 are
depressed from the outer end surface 44 over a predetermined
angular range. In the radial direction, the first discharge recess
443 and the second discharge recess 444 are depressed from the
outer end surface 44 over a predetermined region thereof that
extends from the cam ring inner peripheral surface 42 to some point
toward the cam ring outer peripheral surface 41, and in the
circumferential direction, the first discharge recess 443 and the
second discharge recess 444 are depressed from the outer end
surface 44 over a predetermined angular range.
[0054] When viewed in the direction of the rotational axis, the
first suction recess 431 and the first suction recess 441 are
provided at the same position, and the second suction recess 432
and the second suction recess 442 are provided at the same
position. When the positive vertical axis in the view in the other
direction in FIG. 5 is assumed to be at zero degrees, the second
suction recess 432 and the second suction recess 442 are provided
in an area between about 20 and 90 degrees in the counterclockwise
direction, and the first suction recess 431 and the first suction
recess 441 are provided in an area between about 200 and 270
degrees.
[0055] When viewed in the rotational axis direction, the first
discharge recess 433 and the first discharge recess 443 are
provided at the same position, and the second discharge recess 434
and the second discharge recess 444 are provided at the same
position. When the positive vertical axis in the view in the other
direction in FIG. 5 is assumed to be at zero degrees, the second
discharge recess 434 and the second discharge recess 444 are
provided in an area between about 130 and 175 degrees in the
counterclockwise direction, and the first discharge recess 433 and
the first discharge recess 443 are provided in an area between
about 310 and 355 degrees.
[0056] The cam ring 40 is also formed with two first discharge
through-holes 45 penetrating the cam ring 40 in the rotational axis
direction so as to let the first discharge recess 433 and the first
discharge recess 443 communicate with each other. The cam ring 40
is also formed with two second discharge through-holes 46
penetrating the cam ring 40 in the rotational axis direction so as
to let the second discharge recess 434 and the second discharge
recess 444 communicate with each other.
[0057] The cam ring 40 is also formed with a first through-hole 47
penetrating the cam ring 40 in the rotational axis direction so as
to let the inner end surface 43 between the first suction recess
431 and the second discharge recess 434 and the outer end surface
44 between the first suction recess 441 and the second discharge
recess 444 communicate with each other. The cam ring 40 is also
formed with a second through-hole 48 penetrating the cam ring 40 in
the rotational axis direction to let the inner end surface 43
between the second suction recess 432 and the first discharge
recess 443 and the outer end surface 44 between the second suction
recess 442 and the first discharge recess 443 communicate with each
other.
<Configuration of the Inner Plate 50>
[0058] FIG. 7 depicts the inner plate 50 as viewed in the one
direction and in the other direction along the rotational axis
direction.
[0059] The inner plate 50 is a generally disk-like member with a
through-hole formed at the center thereof. The inner plate 50
includes an inner plate outer peripheral surface 51, an inner plate
inner peripheral surface 52, an inner plate cam ring-side end
surface 53 facing the cam ring 40 in the rotational axis direction,
and an inner plate non-cam ring-side end surface 54 that is an
opposite end surface not facing the cam ring 40 in the rotational
axis direction.
[0060] When viewed in the rotational axis direction, the inner
plate outer peripheral surface 51 is circular as shown in FIG. 7,
and a distance from the rotation center C to the inner plate outer
peripheral surface 51 is substantially the same as a distance from
the rotation center C to the cam ring outer peripheral surface 41
of the cam ring 40.
[0061] When viewed in the rotational axis direction, the inner
plate inner peripheral surface 52 is circular as shown in FIG. 7,
and a distance from the rotation center C to the inner plate inner
peripheral surface 52 is substantially the same as a distance from
the rotation center C to a bottom of the spline 21 (see FIG. 5)
formed on the inner peripheral surface of the rotor 20.
[0062] The inner plate 50 includes inner plate cam ring-side
recesses 530 including multiple recesses depressed from the inner
plate cam ring-side end surface 53 and includes inner plate non-cam
ring-side recesses 540 including multiple recesses depressed from
the inner plate non-cam ring-side end surface 54.
[0063] The inner plate cam ring-side recesses 530 include a first
suction recess 531 and a second suction recess 532. The first
suction recess 531 is formed at a position facing the first suction
recess 431 of the cam ring 40 and constitutes the first suction
port 2. The second suction recess 532 is formed at a position
facing the second suction recess 432 of the cam ring 40 and
constitutes the second suction port 3. The first suction recess 531
and the second suction recess 532 are formed to be
point-symmetrical to each other about the rotation center C.
[0064] The first suction recess 531 includes a first suction inner
portion 538 that constitutes a portion of the first suction port 2
on its side closer to the rotation center C. The second suction
recess 532 includes a second suction inner portion 539 that
constitutes a portion of the second suction port 3 on its side
closer to the rotation center C. These first suction inner portion
538 and second suction inner portion 539 will be described in
detail later.
[0065] The inner plate cam ring-side recesses 530 further include a
second discharge recess 533 formed at a position facing the second
discharge recess 434 of the cam ring 40.
[0066] The inner plate cam ring-side recesses 530 further include
an inner plate second recess 534 that is positioned to correspond
to an area between the second suction recess 532 and the second
discharge recess 533 in the circumferential direction and to face
the columnar groove 232 of the vane groove 23 of the rotor 20 in
the radial direction.
[0067] The inner plate cam ring-side recesses 530 further include
an inner plate first recess 535 that is positioned to correspond to
the first discharge recess 433 in the circumferential direction and
to face the columnar groove 232 of the vane groove 23 of the rotor
20 in the radial direction.
[0068] The inner plate cam ring-side recesses 530 further include a
first recess 536 that is positioned to face the first through-hole
47 of the cam ring 40 and a second recess 537 that is positioned to
face the second through-hole 48 of the cam ring 40.
[0069] The inner plate non-cam ring-side recesses 540 includes an
outer peripheral groove 541 and an inner peripheral groove 542. The
outer peripheral groove 541 is formed along the outer periphery of
the inner plate 50 to be fitted with an outer peripheral O-ring 57
(see FIG. 3). The inner peripheral groove 542 is formed along the
inner periphery of the inner plate 50 to be fitted with an inner
peripheral O-ring 58 (see FIG. 3). The outer peripheral O-ring 57
and the inner peripheral O-ring 58 each seal a gap between the
inner plate 50 and the case 110.
[0070] The inner plate 50 further includes a first discharge
through-hole 55 that penetrates the inner plate 50 in the
rotational axis direction and is positioned to face the first
discharge recess 443 of the cam ring 40. An opening of the first
discharge through-hole 55 facing the cam ring 40 and an opening of
the second discharge recess 533 are formed to be point-symmetrical
to each other about the rotation center C.
[0071] The inner plate 50 further includes an inner plate first
through-hole 56 that penetrates the inner plate 50 in the
rotational axis direction and is positioned to correspond to the
first suction recess 531 in the circumferential direction and to
face the columnar groove 232 of the vane groove 23 of the rotor 20
in the radial direction.
<Configuration of the Outer Plate 60>
[0072] FIG. 8 depicts the outer plate 60 as viewed in the other
direction and in the one direction along the rotational axis
direction.
[0073] The outer plate 60 is a generally disk-like member with a
through-hole formed at the center thereof. The outer plate 60
includes an outer plate outer peripheral surface 61, an outer plate
inner peripheral surface 62, an outer plate cam ring-side end
surface 63 facing the cam ring 40 in the rotational axis direction,
and an outer plate non-cam ring-side end surface 64 that is an
opposite end surface not facing the cam ring 40 in the rotational
axis direction.
[0074] When viewed in the rotational axis direction, the outer
plate outer peripheral surface 61 has a shape formed by cutting out
two portions from a base circular shape, as shown in FIG. 8. A
distance from the rotation center C to a periphery of the base
circular shape is substantially the same as a distance from the
rotation center C to the cam ring outer peripheral surface 41 of
the cam ring 40. The two cutouts include a first suction cutout 611
that is positioned to face the first suction recess 441 and
constitutes the first suction port 2, and a second suction cutout
612 that is positioned to face the second suction recess 442 and
constitutes the second suction port 3. The outer plate outer
peripheral surfaces 61 are formed to be point-symmetrical to each
other about the rotation center C. The first suction cutout 611 and
the second suction cutout 612 are formed to be point-symmetrical to
each other about the rotation center C.
[0075] The first suction cutout 611 includes a first suction inner
portion 613 that constitutes a portion of the first suction port 2
on its side closer to the rotation center C. The second suction
cutout 612 includes a second suction inner portion 614 that
constitutes a portion of the second suction port 3 on its side
closer to the rotation center C. These first suction inner portion
613 and second suction inner portion 614 will be described in
detail later.
[0076] When viewed in the rotational axis direction, the outer
plate inner peripheral surface 62 is circular as shown in FIG. 8,
and a distance from the rotation center C to the outer plate inner
peripheral surface 62 is substantially the same as the distance
from the rotation center C to the bottom of the spline 21 formed on
the inner peripheral surface of the rotor 20.
[0077] The outer plate 60 includes outer plate cam ring-side
recesses 630 including multiple recesses depressed from the outer
plate cam ring-side end surface 63.
[0078] The outer plate cam ring-side recesses 630 include a first
discharge recess 631 positioned to face the first discharge recess
443 of the cam ring 40.
[0079] The outer plate cam ring-side recesses 630 further include
an outer plate first recess 632 that is positioned to correspond to
an area between the first suction cutout 611 and the first
discharge recess 631 in the circumferential direction and to face
the columnar groove 232 of the vane groove 23 of the rotor 20 in
the radial direction.
[0080] The outer plate cam ring-side recesses 630 further include
an outer plate second recess 633 that is positioned to correspond
to the second discharge recess 444 of the cam ring 40 in the
circumferential direction and to face the columnar groove 232 of
the vane groove 23 of the rotor 20 in the radial direction.
[0081] The outer plate cam ring-side recesses 630 further include a
first V-shaped groove 634 that is parallel to the rotational axis
direction, has a V-shaped cross-section along a plane perpendicular
to the outer plate outer peripheral surface 61, and deepens as it
goes from the upstream side to the downstream side in the
rotational direction. A downstream-side end of the first V-shaped
groove 634 is connected to an upstream-side end of the first
discharge recess 631.
[0082] The outer plate cam ring-side recesses 630 further include a
second V-shaped groove 635 that is parallel to the rotational axis
direction, has a V-shaped cross-section along a plane perpendicular
to the outer plate outer peripheral surface 61, and deepens as it
goes from the upstream side to the downstream side in the
rotational direction. A downstream-side end of the second V-shaped
groove 635 is connected to an upstream-side end of a second
discharge through-hole 65.
[0083] The outer plate 60 further includes a second discharge
through-hole 65 that penetrates the outer plate 60 in the
rotational axis direction and is positioned to face the second
discharge recess 444 of the cam ring 40. An opening of the second
discharge through-hole 65 facing the cam ring 40 and an opening of
the first discharge recess 631 are formed to be point-symmetrical
to each other about the rotation center C.
[0084] The outer plate 60 further includes an outer plate second
through-hole 66 that penetrates the outer plate 60 in the
rotational axis direction and is positioned to correspond to the
second suction cutout 612 in the circumferential direction and to
face the columnar groove 232 of the vane groove 23 of the rotor 20
in the radial direction.
[0085] The outer plate 60 further includes a first through-hole 67
and a second through-hole 68; the first through-hole 67 penetrates
the outer plate 60 in the rotational axis direction and is
positioned to face the first through-hole 47 of the cam ring 40,
and the second through-hole 68 penetrates the outer plate 60 in the
rotational axis direction and is positioned to face the second
through-hole 48 of the cam ring 40.
<Configuration of the Housing 100>
[0086] The housing 100 accommodates the rotor 20, the vanes 30, the
cam ring 40, the inner plate 50, and the outer plate 60. The
housing 100 accommodates the one end of the rotary shaft 10 and
lets the other end thereof protrude from the housing 100.
[0087] The case 110 and the cover 120 are tightened together with
bolts.
(Configuration of the Case 110)
[0088] FIG. 9 depicts the case 110 as viewed in the one direction
along the rotational axis direction.
[0089] The case 110 is a closed-end cylindrical member and
includes, at the center of its bottom, a case-side bearing 111 that
rotatably supports the one end of the rotary shaft 10.
[0090] The case 110 further includes an inner plate fitting portion
112 to which the inner plate 50 is fitted. The inner plate fitting
portion 112 includes an inner diameter-side fitting portion 113
located close to the rotation center C (i.e., located on an inner
diameter side) and an outer diameter-side fitting portion 114
located farther from the rotation center C (i.e., located on an
outer diameter side).
[0091] As shown in FIG. 3, the inner diameter-side fitting portion
113 is provided on the outer diameter side of the case-side bearing
111 and includes an inner diameter-side cover portion 113a covering
a part of a periphery of the inner plate inner peripheral surface
52 of the inner plate 50 and an inner diameter-side restricting
portion 113b restricting the inner plate 50 from moving toward the
bottom. When viewed in the rotational axis direction, the inner
diameter-side cover portion 113a has a circular shape in which a
distance from the rotation center C to the inner diameter-side
cover portion 113a is shorter than the distance from the rotation
center C to the inner plate inner peripheral surface 52. The inner
diameter-side restricting portion 113b has a donut-shaped surface
perpendicular to the rotational axis direction. A distance from the
rotation center C to an inner circle of the inner diameter-side
restricting portion 113b is the same as the distance from the
rotation center C to the inner diameter-side cover portion 113a,
and a distance from the rotation center C to an outer circle of the
inner diameter-side restricting portion 113b is longer than the
distance from the rotation center C to the inner plate inner
peripheral surface 52.
[0092] As shown in FIG. 3, the outer diameter-side fitting portion
114 includes an outer diameter-side cover portion 114a covering a
part of a periphery of the inner plate outer peripheral surface 51
of the inner plate 50 and an outer diameter-side restricting
portion 114b restricting the inner plate 50 from moving toward the
bottom. When viewed in the rotational axis direction, the outer
diameter-side cover portion 114a has a circular shape in which a
distance from the rotation center C to the outer diameter-side
cover portion 114a is longer than a distance from the rotation
center C to the inner plate outer peripheral surface 51. The outer
diameter-side restricting portion 114b has a donut-shaped surface
perpendicular to the rotational axis direction. A distance from the
rotation center C to an outer circle of the outer diameter-side
restricting portion 114b is the same as the distance from the
rotation center C to the outer diameter-side cover portion 114a,
and a distance from the rotation center C to an inner circle of the
outer diameter-side restricting portion 114b is shorter than the
distance from the rotation center C to the inner plate outer
peripheral surface 51.
[0093] The inner plate 50 is inserted into the bottom of the case
110 until the inner peripheral O-ring 58, which is fitted to the
inner peripheral groove 542 of the inner plate 50, abuts on the
inner diameter-side restricting portion 113b and the outer
peripheral O-ring 57, which is fitted to the outer peripheral
groove 541, abuts on the outer diameter-side restricting portion
114b. Thus, the inner peripheral O-ring 58 contacts the inner
peripheral groove 542 of the inner plate 50 and the inner
diameter-side cover portion 113a and the inner diameter-side
restricting portion 113b of the case 110 while the outer peripheral
O-ring 57 contacts the outer peripheral groove 541 of the inner
plate 50 and the outer diameter-side cover portion 114a and the
outer diameter-side restricting portion 114b of the case 110. This
seals the gap between the case 110 and the inner plate 50. As a
result, a space inside the case 110 is partitioned into a space S1
closer to the opening of the case 110 than the inner plate fitting
portion 112 and a space S2 closer to the bottom of the case 110
than the inner plate fitting portion 112. The space S1 closer to
the opening of the case 110 than the inner plate fitting portion
112 constitutes a suction channel R1 for flow of oil suctioned from
the first suction port 2 and the second suction port 3. The space
S2 closer to the bottom of the case 110 than the inner plate
fitting portion 112 forms a first discharge channel R2 for flow of
oil discharged from the first discharge port 4.
[0094] Separately from the accommodation space for accommodating
the rotor 20, the vanes 30, the cam ring 40, the inner plate 50,
and the outer plate 60, the case 110 includes a case outer recess
115 that is located radially outside of the accommodation space and
depressed from the opening side in the rotational axis direction.
The case outer recess 115 faces a cover outer recess 123 (described
later) formed in the cover 120 and constitutes a case second
discharge channel R3 for flow of oil discharged from the second
discharge port 5.
[0095] As shown in FIG. 1, the case 110 further includes a suction
inlet 116 that lets the space 51 closer to the opening of the case
110 than the inner plate fitting portion 112 communicate with the
outside of the case 110. The suction inlet 116 includes a columnar
hole formed in a side wall of the case 110; a columnar direction of
the hole is perpendicular to the rotational axis direction. The
suction inlet 116 constitutes the suction channel R1 for flow of
oil suctioned from the first suction port 2 and the second suction
port 3.
[0096] As shown in FIG. 1, the case 110 further includes a first
discharge outlet 117 that lets the space S2 closer to the bottom of
the case 110 than the inner plate fitting portion 112 communicate
with the outside of the case 110. The first discharge outlet 117
includes a columnar hole formed in the side wall of the case 110; a
columnar direction of the hole is perpendicular to the rotational
axis direction. The first discharge outlet 117 constitutes the
first discharge channel R2 for flow of oil discharged from the
first discharge port 4.
[0097] As shown in FIG. 1, the case 110 further includes a second
discharge outlet 118 that lets the case outer recess 115
communicate with the outside of the case 110. The second discharge
outlet 118 includes a columnar hole formed in a side wall of the
case outer recess 115 of the case 110; a columnar direction of the
hole is perpendicular to the rotational axis direction. The second
discharge outlet 118 constitutes the case second discharge channel
R3 for flow of oil discharged from the second discharge port 5.
(Configuration of the Cover 120)
[0098] As shown in FIG. 2, the cover 120 includes at its center a
cover-side bearing 121 that rotatably supports the rotary shaft
10.
[0099] The cover 120 includes a cover second discharge recess 122
that is positioned to face the second discharge through-hole 65 and
the outer plate second through-hole 66 of the outer plate 60 and
depressed in the rotational axis direction from an end surface of
the cover 120 facing the case 110.
[0100] The cover 120 further includes a cover outer recess 123 and
a cover recess connecting portion 124. The cover outer recess 123
is positioned radially outside of the cover second discharge recess
122 and depressed in the rotational axis direction from the end
surface of the cover 120 facing the case 110. The cover recess
connecting portion 124 connects the cover second discharge recess
122 and the cover outer recess 123 at a position on the other
direction side in the rotational axis direction relative to the end
face of the cover 120 facing the case 110. The cover outer recess
123 opens at a position at which the cover outer recess 123 does
not face the aforementioned accommodation space in the case 110 but
faces the case outer recess 115. The cover second discharge recess
122, the cover recess connecting portion 124, and the cover outer
recess 123 constitute a cover second discharge channel R4 (see FIG.
4) for flow of oil discharged from the second discharge port 5. Oil
discharged from the second discharge port 5 flows into the case
second discharge channel R3 via the cover recess connecting portion
124 and also flows into the outer plate second through-hole 66 via
the cover second discharge recess 122.
[0101] The cover 120 further includes a cover suction recess 125
depressed in the rotational axis direction from the end surface of
the cover 120 facing the case 110; in the cover 120, the cover
suction recess 125 is positioned to face the first suction cutout
611 and the second suction cutout 612 of the outer plate 60 and to
face a space that is within the space S1 closer to the opening of
the case 110 than the inner plate fitting portion 112 and that is
radially outside of the cam ring outer peripheral surface 41 of the
cam ring 40.
[0102] The cover suction recess 125 constitutes the suction channel
R1 for flow of oil suctioned from the suction inlet 116 into the
pump chambers through the first suction port 2 and the second
suction port 3.
[0103] The cover 120 further includes a first cover recess 127 and
a second cover recess 128 depressed in the rotational axis
direction from the end surface of the cover 120 facing the case
110; the first cover recess 127 and the second cover recess 128 are
positioned to face the first through-hole 67 and the second
through-hole 68, respectively, of the outer plate 60.
<Functions of the Vane Pump 1>
[0104] The vane pump 1 of the present embodiment includes ten vanes
30 and ten pump chambers. As the ten vanes 30 contact the cam ring
inner peripheral surface 42 of the cam ring 40, each of the pump
chambers is formed by two adjacent vanes 30, an outer peripheral
surface of the rotor 20 between the two adjacent vanes 30, the cam
ring inner peripheral surface 42 between the two adjacent vanes 30,
the inner plate cam ring-side end surface 53 of the inner plate 50,
and the outer plate cam ring-side end surface 63 of the outer plate
60. Taking a look at one pump chamber, the pump chamber makes one
revolution around the rotary shaft 10 as the rotary shaft 10 makes
one rotation and thus the rotor 20 makes one rotation. During one
revolution of the pump chamber, oil suctioned from the first
suction port 2 into the pump chamber is compressed and pressurized
therein before being discharged from the first discharge port 4,
and oil suctioned from the second suction port 3 into the pump
chamber is compressed and pressurized therein before being
discharged from the second discharge port 5.
<Shape of the Suction Inner Portion>
[0105] FIG. 10 depicts the cam ring 40 and the inner plate 50 as
viewed in the one direction. FIG. 10 particularly depicts the first
suction inner portion 538 of the inner plate 50.
[0106] FIG. 11 is a sectional view taken along the line XI-XI in
FIG. 10. FIG. 12 is a perspective view of the rotor of the multiple
vanes 30, the cam ring 40, and the outer plate 60.
[0107] Since the first suction inner portion 538 and the second
suction inner portion 539 of the inner plate 50 and the first
suction inner portion 613 and the second suction inner portion 614
of the outer plate 60 are substantially of the same shape, these
may be collectively referred to as a "suction inner portion 710" in
the following description. Also, when there is no need to
distinguish between the first suction port 2 and the second suction
port 3, the first suction port 2 and the second suction port 3 may
be collectively referred to as a "suction port" in the following
description.
[0108] The suction inner portion 710 includes a suction inner body
711 contoured to the shape of the curved surface portion 22 of the
rotor 20, and a suction inner recess 712, which is an example of
the second recess, depressed toward the rotation center C relative
to the curved surface portion 22 of the rotor 20. The suction inner
portion 710 further includes a suction inner intermediate portion
713 between the suction inner body 711 and the suction inner recess
712.
[0109] The suction inner body 711 has an arc shape centered on the
rotation center C, and a distance from the rotation center C to the
suction inner body 711 is the same as a distance from the rotation
center C to the curved surface portion 22 of the rotor 20.
[0110] The suction inner recess 712 is formed to connect to an end
of the suction port on the upstream side (upstream end). Taking the
first suction port 2 as an example, a rotational angle of the end
of the suction port on the upstream side (upstream end) is equal to
a rotational angle of upstream ends of the first suction recess 431
and the first suction recess 441 of the cam ring 40, the first
suction recess 531 of the inner plate 50, and the first suction
cutout 611 of the outer plate 60, all of which constitute the first
suction port 2, because the upstream ends of these portions all
have the same rotational angle. In other words, the suction inner
recess 712 of the first suction recess 531 is formed to connect to
the upstream end of the first suction recess 531 of the inner plate
50.
[0111] A distance from the rotation center C to a portion of the
suction inner recess 712 that is most depressed toward the rotation
center C is equal to a distance from the rotation center C to an
end of the rotor recess 24 of the rotor 20 in the rotational axis
direction.
[0112] The suction inner intermediate portion 713 has a shape that
is contoured to the shape of the inner peripheral surface of the
cam ring 40. In other words, a distance from the rotation center C
to the suction inner intermediate portion 713 at each rotational
angle is shorter by a predetermined distance than a distance L from
the rotation center C to the cam ring inner peripheral surface 42
of the cam ring 40 at each rotational angle.
[0113] The suction inner recess 712 and the upstream end of the
suction port are connected at a curved surface of a predetermined
radius, and the suction inner body 711 and the suction inner
intermediate portion 713 are connected at a curved surface of a
predetermined radius. The suction inner body 711 and a downstream
end of the suction port are connected at a curved surface of a
predetermined radius.
[0114] Below a description will be given of advantages of the vane
pump 1 of the present embodiment in comparison with a comparative
configuration.
[0115] As a vane pump of a comparative configuration, assume a
configuration in which a recess depressed from the curved surface
portion 22 toward the rotation center C is formed over the entire
region of the curved surface portion 22 in the rotational axis
direction, unlike the vane pump 1 of the present embodiment.
[0116] In the vane pump 1 of the present embodiment, the curved
surface portion 22 formed between two adjacent vane grooves 23 has
an arc shape centered on the rotation center C, and accordingly the
vane pump 1 has a smaller pump chamber capacity as compared to the
vane pump of the comparative configuration. The vane pump of the
comparative configuration has a larger pump chamber capacity than
that of the vane pump 1 of the present embodiment by the amount
equal to the volume of the recess formed on the curved surface
portion 22 over the entire region thereof in the rotational axis
direction and depressed toward the rotation center C.
[0117] Hence, an amount of oil suctioned into the pump chambers of
the vane pump 1 of the present embodiment is smaller than an amount
of oil suctioned into pump chambers of the vane pump of the
comparative configuration. As a result, an absolute amount of air
bubbles (air) contained in the oil suctioned into the pump chambers
of the vane pump 1 of the present embodiment is smaller than air
bubbles suctioned into the pump chambers of the vane pump of the
comparative configuration. If a large amount of air bubbles is
suctioned into the pump chambers, a sound may occur as the air
bubbles collapse in subsequent strokes. A sound may also occur as
the air bubbles suctioned into the pump chambers are split or the
split air bubbles hit the inner peripheral surface of the cam ring
40 and the like. Also, an amount of oil other than the air bubbles
that can be suctioned into the pump chambers relative to the pump
chamber capacity is reduced by the amount of air bubbles suctioned
into the pump chambers, which means that suctioning of a large
amount of air bubbles into the pump chambers may lead to a reduced
suction/discharge efficiency or a fluctuation in discharge
pressure. The vane pump 1 of the present embodiment can reduce the
absolute amount of air bubbles suctioned into the pump chambers as
compared to the vane pump of the comparative example, and thus can
suppress a decrease in suction/discharge efficiency, a fluctuation
in discharge pressure, and occurrence of noise.
[0118] Additionally, in the vane pump 1 of the present embodiment,
the rotor recesses 24 depressed toward the rotation center C from
each curved surface portion 22 are formed on respective ends of the
rotor 20 in the rotational axis direction. The rotor recesses 24
facilitate suction of oil into the pump chambers as compared to a
configuration without the rotor recesses 24. This increases the
amount of oil suctioned into the pump chambers as compared to the
configuration without the rotor recesses 24, increasing the suction
efficiency. As a result, this can suppress an excessive decrease in
the amount of oil suctioned into the pump chambers that may
otherwise occur due to the outer periphery of the rotor 20 having
the arc-like curved surface portion 22 centered on the rotation
center C.
[0119] The rotor recesses 24 are formed on the ends of the rotor 20
in the rotational axis direction, which face the first suction
recess 431 and the first suction recess 441 of the cam ring 40
located on the ends of the cam ring 40 in the rotational axis
direction and constituting the suction port. This increases the
amount of oil suctioned into the pump chambers as compared to, for
example, a configuration in which the rotor recesses 24 are formed
at the center of the rotor 20 in the rotational axis direction that
does not face the first suction recess 431 and the first suction
recess 441 of the cam ring 40.
[0120] The size of each rotor recess 24 in the rotational axis
direction is smaller than that of the first suction recess 431 and
the first suction recess 441 of the cam ring 40. This can reduce an
absolute amount of air suctioned into the pump chambers while
suppressing an excessive decrease in the amount of oil suctioned
into the pump chambers that may otherwise occur due to the outer
periphery of the rotor 20 having the arc-like curved surface
portion 22 centered on the rotation center C.
[0121] In the vane pump 1 of the present embodiment, each rotor
recess 24 of the rotor 20 is formed at the center of the curved
surface portion 22 of the rotor 20 in the circumferential direction
and is not formed near the vane groove 23. This increases an area
of a portion of the rotor 20 for supporting the vane 30, as
compared to a configuration in which the rotor recess 24 is also
formed near the vane groove 23. This enables the rotor 20 to
support the vane 30 over a wide area and thus helps avoid falling
of the vane 30 even if the vane 30 is pushed by high-pressure oil
flowing into the columnar groove 232 of the vane groove 23.
[0122] In the vane pump 1 of the present embodiment, the suction
inner portion 710 (the first suction inner portion 538 and the
second suction inner portion 539 of the inner plate 50 and the
first suction inner portion 613 and the second suction inner
portion 614 of the outer plate 60) of the suction port includes the
suction inner recess 712 depressed toward the rotation center C
relative to the curved surface portion 22 of the rotor 20. This
shape increases an opening area of the suction port as compared to,
for example, a configuration in which the suction inner body 711 is
formed over the entire region of the suction inner portion 710 in
the circumferential direction and the suction inner recess 712 is
not formed. As a result, the vane pump 1 of the present embodiment
can have increased suction efficiency as compared to a vane pump
having the suction inner portion 710 that is not formed with the
suction inner recess 712.
[0123] In the vane pump 1 of the present embodiment, the suction
inner recess 712 is formed to connect to the upstream end of the
suction port. This can increase the opening area of the suction
port when the pump chamber capacity starts to increase during an
initial phase of a suction stroke. As a result, the vane pump 1 of
the present embodiment can increase the amount of oil suctioned
therein and thus have increased suction efficiency.
[0124] At the downstream end of the suction port, where an amount
of protrusion of the vane 30 from the vane groove 23 of the rotor
20 is large, the suction inner body 711, whose distance from the
rotation center C is the same as the distance from the rotation
center C to the curved surface portion 22 of the rotor 20, supports
an end of the vane 30, and this helps avoid falling of the vane
30.
Second Embodiment
[0125] FIG. 13 depicts a schematic configuration of a suction inner
portion 720 of a vane pump 702 of the second embodiment.
[0126] The vane pump 702 of the second embodiment differs from the
vane pump 1 of the first embodiment in that the vane pump 702
includes a suction inner portion 720 that corresponds to the
suction inner portion 710 of the vane pump 1 of the first
embodiment. Below a description will be given of differences from
the vane pump 1 of the first embodiment. The same structures and
functions between the vane pump 702 of the second embodiment and
the vane pump 1 of the first embodiment are denoted by the
respective same reference numerals and detailed description thereof
will be omitted.
[0127] The suction inner portion 720 includes a suction inner body
721 contoured to the shape of the curved surface portion 22 of the
rotor 20, and a suction inner recess 722 depressed toward the
rotation center C relative to the curved surface portion 22 of the
rotor 20. The suction inner portion 720 further includes a suction
inner intermediate portion 723 between the suction inner body 721
and the suction inner recess 722.
[0128] The suction inner recess 722 is formed to connect to an end
of the suction port on the downstream side (downstream end). Taking
the first suction port 2 as an example, a rotational angle of the
end of the suction port on the downstream side (downstream end) is
equal to a rotational angle of downstream ends of the first suction
recess 431 and the first suction recess 441 of the cam ring 40, the
first suction recess 531 of the inner plate 50, and the first
suction cutout 611 of the outer plate 60, all of which constitute
the first suction port 2, because the downstream ends of these
portions all have the same rotational angle. In other words, the
suction inner recess 722 in the first suction recess 531 is formed
to connect to the downstream end of the first suction recess 531 of
the inner plate 50.
[0129] A distance from the rotation center C to a portion of the
suction inner recess 722 that is most depressed toward the rotation
center C is equal to the distance from the rotation center C to the
end of the rotor recess 24 of the rotor 20 in the rotational axis
direction.
[0130] The suction inner intermediate portion 723 is formed to
connect the suction inner recess 722 and a center portion 724 of
the suction inner body 721 located between upstream and downstream
ends of the suction inner portion 720.
[0131] The suction inner recess 722 and the downstream end of the
suction port are connected at a curved surface of a predetermined
radius, and the suction inner body 721 and the suction inner
intermediate portion 723 are connected at a curved surface of a
predetermined radius. The suction inner body 721 and an upstream
end of the suction port are connected at a curved surface of a
predetermined radius.
[0132] In the vane pump 702 of the second embodiment, the suction
inner portion 720 (the first suction inner portion 538 and the
second suction inner portion 539 of the inner plate 50 and the
first suction inner portion 613 and the second suction inner
portion 614 of the outer plate 60) of the suction port includes the
suction inner recess 722 depressed toward the rotation center C
relative to the curved surface portion 22 of the rotor 20. This
shape increases an opening area of the suction port as compared to,
for example, a configuration in which the suction inner body 721 is
formed over the entire region of the suction inner portion 720 in
the circumferential direction and the suction inner recess 722 is
not formed. As a result, the vane pump 702 of the second embodiment
can have increased suction efficiency as compared to a vane pump
that is not formed with the suction inner recess 722.
[0133] In the vane pump 702 of the second embodiment, the suction
inner recess 722 is formed to connect to the downstream end of the
suction port. This can increase the opening area of the suction
port when the pump chamber capacity almost reaches a maximum. As a
result, the vane pump 702 of the second embodiment can increase the
amount of oil suctioned therein and thus have increased suction
efficiency.
Third Embodiment
[0134] FIG. 14 depicts a schematic configuration of a suction inner
portion 730 of a vane pump 703 of the third embodiment.
[0135] The vane pump 703 of the third embodiment differs from the
vane pump 1 of the first embodiment in that the vane pump 703
includes a suction inner portion 730 that corresponds to the
suction inner portion 710 of the vane pump 1 of the first
embodiment. Below a description will be given of differences from
the vane pump 1 of the first embodiment. The same structures and
functions between the vane pump 703 of the third embodiment and the
vane pump 1 of the first embodiment are denoted by the respective
same reference numerals and detailed description thereof will be
omitted.
[0136] The suction inner portion 730 of the third embodiment
differs from the suction inner portion 710 of the first embodiment
and the suction inner portion 720 of the second embodiment in that
a suction inner recess 732 that is most depressed toward the
rotation center C is formed at the center of the suction inner
portion 730 between upstream and downstream ends thereof. A
distance from the rotation center C to a portion of the suction
inner recess 732 that is most depressed toward the rotation center
C is equal to the distance from the rotation center C to the end of
the rotor recess 24 of the rotor 20 in the rotational axis
direction.
[0137] The suction inner portion 730 further includes an
upstream-side connecting portion 735 that connects the suction
inner recess 732 and an upstream point 734. The upstream point 734
is located at the upstream end of the suction inner portion 730,
and a distance from the rotation center C to the upstream point 734
is equal to the distance from the rotation center C to the curved
surface portion 22 of the rotor 20. The suction inner portion 730
further includes a downstream-side connecting portion 737 that
connects the suction inner recess 732 and a downstream point 736.
The downstream point 736 is located at the downstream end of the
suction inner portion 730, and a distance from the rotation center
C to the downstream point 736 is equal to the distance from the
rotation center C to the curved surface portion 22 of the rotor
20.
[0138] The upstream-side connecting portion 735 and the upstream
end of the suction port are connected at a curved surface of a
predetermined radius, and the downstream-side connecting portion
737 and the downstream end of the suction port are connected at a
curved surface of a predetermined radius.
[0139] In the vane pump 703 of the third embodiment, the suction
inner portion 730 (the first suction inner portion 538 and the
second suction inner portion 539 of the inner plate 50 and the
first suction inner portion 613 and the second suction inner
portion 614 of the outer plate 60) of the suction port includes the
suction inner recess 732 depressed toward the rotation center C
relative to the curved surface portion 22 of the rotor 20. This
shape increases an opening area of the suction port as compared to,
for example, a configuration in which a distance from the rotation
center C to any point on the suction inner portion 730 in the
circumferential direction is the same as the distance from the
rotation center C to the curved surface portion 22 of the rotor 20.
As a result, the vane pump 703 of the third embodiment can have
increased suction efficiency as compared to a vane pump that is not
formed with the suction inner recess 732.
[0140] In the vane pump 703 of the third embodiment, the suction
inner recess 732 is formed at the center in the circumferential
direction of the suction inner portion 730 of the suction port.
This can increase the opening area of the suction port when the
pump chamber capacity starts to increase and then the rotor 20
rotates by about 7 to 45 degrees. This can increase the opening
area of the suction port immediately after the start of suctioning
in a high rotation speed range of the rotor 20 in which the vane
pump 703 starts suctioning the oil only after the rotor 20 have
rotated by, e.g., about 5 degrees after the start of increase in
the pump chamber capacity. This leads to increased suction
efficiency.
[0141] At the downstream end of the suction port, where an amount
of protrusion of the vane 30 from the vane groove 23 of the rotor
20 is large, a distance from the rotation center C gradually
increases from the upstream end side to the downstream end. This
makes it easy to support the end of the vane 30 and thus helps
avoid falling of the vane 30.
Fourth Embodiment
[0142] FIG. 15 depicts a schematic configuration of a suction inner
portion 740 of a vane pump 704 of the fourth embodiment.
[0143] The vane pump 704 of the fourth embodiment differs from the
vane pump 1 of the first embodiment in that the vane pump 704
includes a suction inner portion 740 that corresponds to the
suction inner portion 710 of the vane pump 1 of the first
embodiment. Below a description will be given of differences from
the vane pump 1 of the first embodiment. The same structures and
functions between the vane pump 704 of the fourth embodiment and
the vane pump 1 of the first embodiment are denoted by the
respective same reference numerals and detailed description thereof
will be omitted.
[0144] The suction inner portion 740 of the fourth embodiment
differs from the suction inner portion 710 of the first embodiment
in that a portion corresponding to the suction inner recess 712 of
the suction inner portion 710 of the first embodiment is formed
over the entire suction inner portion 740 that constitutes a
portion of the suction port on the rotation center C side. In other
words, the suction inner portion 740 of the fourth embodiment is
not provided with portions corresponding to the suction inner body
711 and the suction inner intermediate portion 713.
[0145] That is, the suction inner portion 740 of the fourth
embodiment has an arc shape centered on the rotation center C and
includes a suction inner recess 742 whose distance from the
rotation center C is equal to the distance from the rotation center
C to the end of the rotor recess 24 of the rotor 20 in the
rotational axis direction. The suction inner recess 742 is formed
over the entire region of the suction port in the circumferential
direction from the upstream to downstream ends thereof.
[0146] The suction inner recess 742 and the upstream end of the
suction port are connected at a curved surface of a predetermined
radius, and the suction inner recess 742 and the downstream end of
the suction port are connected at a curved surface of a
predetermined radius.
[0147] In the vane pump 704 of the fourth embodiment, the suction
inner portion 740 (the first suction inner portion 538 and the
second suction inner portion 539 of the inner plate 50 and the
first suction inner portion 613 and the second suction inner
portion 614 of the outer plate 60) of the suction port includes the
suction inner recess 742 depressed toward the rotation center C
relative to the curved surface portion 22 of the rotor 20. This
shape increases an opening area of the suction port as compared to,
for example, a configuration in which a distance from the rotation
center C to any point on the suction inner portion 740 in the
circumferential direction is the same as the distance from the
rotation center C to the curved surface portion 22 of the rotor 20.
As a result, the vane pump 704 of the fourth embodiment can have
increased suction efficiency as compared to a vane pump that is not
formed with the suction inner recess 742.
[0148] In the vane pump 704 of the fourth embodiment, the suction
inner recess 742 is formed over the entire region of the suction
port in the circumferential direction from the upstream to
downstream ends thereof. This increases the opening area of the
suction port as compared to, for example, a configuration in which
the suction inner recess 742 is formed in a part of the suction
port in the circumferential direction, and thus can increase
suction efficiency.
[0149] In the above first to fourth embodiments, the portion of the
suction inner recess (e.g., the suction inner recess 722) of the
suction inner portion (e.g., the suction inner portion 710) that is
most depressed toward the rotation center C is at the same distance
from the rotation center C as the distance from the rotation center
C to the end in the rotational axis direction of the rotor recess
24 of the rotor 20. However, the present invention is not limited
to these embodiments. The portion of the suction inner recess most
depressed toward the rotation center C may be depressed closer to
the rotation center C than the rotor recess 24 of the rotor 20.
This increases the opening area of the suction port further and
thus increases suction efficiency.
Fifth Embodiment
[0150] A vane pump 705 of the fifth embodiment differs from the
vane pump of the above first to fourth embodiments in that portions
of the inner plate 50 and the outer plate 60 of the vane pump 705
constituting the first discharge port 4 or the second discharge
port 5 are depressed toward the rotation center C relative to the
curved surface portion 22 of the rotor 20. Below a description will
be given of differences from the vane pump of the first to fourth
embodiments. The same structures and functions between the vane
pump 705 of the fifth embodiment and the vane pump of the first to
fourth embodiments are denoted by the respective same reference
numerals and detailed description thereof will be omitted.
[0151] FIG. 16 depicts an inner plate 850 of the fifth embodiment
as viewed in the one direction and in the other direction along the
rotational axis direction.
[0152] A first discharge through-hole 855 of the inner plate 850 of
the fifth embodiment includes a first discharge inner portion 858
that constitutes a portion of the first discharge port 4 on its
side closer to the rotation center C. A second discharge recess 853
of the inner plate 850 includes a second discharge inner portion
859 that constitutes a portion of the second discharge port 5 on
its side closer to the rotation center C.
[0153] FIG. 17 depicts an outer plate 860 of the fifth embodiment
as viewed in the other direction and in the one direction along the
rotational axis direction.
[0154] A first discharge recess 863 of the outer plate 860 of the
fifth embodiment includes a first discharge inner portion 868 that
constitutes a portion of the first discharge port 4 on its side
closer to the rotation center C. A second discharge through-hole
865 of the outer plate 860 includes a second discharge inner
portion 869 that constitutes a portion of the second discharge port
5 on its side closer to the rotation center C.
[0155] Since the first discharge inner portion 858 and the second
discharge inner portion 859 of the inner plate 850 and the first
discharge inner portion 868 and the second discharge inner portion
869 of the outer plate 860 have the substantially same shape, these
may be collectively referred to as a "discharge inner portion 800"
in the following description. Also, when there is no need to
distinguish between the first discharge port 4 and the second
discharge port 5, the first discharge port 4 and the second
discharge port 5 may be collectively referred to as a "discharge
port" in the following description.
[0156] FIG. 18 depicts the cam ring 40 and the inner plate 850 as
viewed in the one direction.
[0157] The discharge inner portion 800 includes a discharge inner
body 801 contoured to the shape of the curved surface portion 22 of
the rotor 20, and a discharge inner recess 802, which is an example
of the second recess, depressed toward the rotation center C
relative to the curved surface portion 22 of the rotor 20. The
discharge inner portion 800 further includes a discharge inner
intermediate portion 803 between the discharge inner body 801 and
the discharge inner recess 802.
[0158] The discharge inner body 801 has an arc shape centered on
the rotation center C, and a distance from the rotation center C to
the discharge inner body 801 is the same as the distance from the
rotation center C to the curved surface portion 22 of the rotor
20.
[0159] The discharge inner recess 802 is formed to connect to an
end of the discharge port on the upstream side (upstream end).
Taking the first discharge port 4 as an example, a rotational angle
of the end of the discharge port on the upstream side (upstream
end) is equal to a rotational angle of upstream ends of the first
discharge recess 433 and the first discharge recess 443 of the cam
ring 40, the first discharge through-hole 855 of the inner plate
850, and the first discharge recess 863 of the outer plate 860, all
of which constitute the first discharge port 4, because the
upstream ends of these portions all have the same rotational angle.
In other words, the discharge inner recess 802 of the first
discharge inner portion 858 is formed to connect to the upstream
end of the first discharge through-hole 855 of the inner plate
850.
[0160] A distance from the rotation center C to a portion of the
discharge inner recess 802 that is most depressed toward the
rotation center C is equal to the distance from the rotation center
C to the end of the rotor recess 24 of the rotor 20 in the
rotational axis direction.
[0161] The discharge inner intermediate portion 803 is formed to
connect the discharge inner recess 802 and a center portion 804 of
the discharge inner body 801 located between upstream and
downstream ends of the discharge inner portion 800.
[0162] The discharge inner recess 802 and the upstream end of the
discharge port are connected at a curved surface of a predetermined
radius, and the discharge inner body 801 and the discharge inner
intermediate portion 803 are connected at a curved surface of a
predetermined radius. The discharge inner body 801 and a downstream
end of the discharge port are connected at a curved surface of a
predetermined radius.
[0163] In the vane pump 705 of the fifth embodiment, the discharge
inner portion 800 (the first discharge inner portion 858 and the
second discharge inner portion 859 of the inner plate 850 and the
first discharge inner portion 868 and the second discharge inner
portion 869 of the outer plate 860) of the discharge port includes
the discharge inner recess 802 depressed toward the rotation center
C relative to the curved surface portion 22 of the rotor 20. This
shape increases an opening area of the discharge port as compared
to, for example, a configuration in which the discharge inner body
801 is formed over the entire region of the discharge inner portion
800 in the circumferential direction and the discharge inner recess
802 is not formed. As a result, the vane pump 705 of the fifth
embodiment can have increased discharge efficiency as compared to a
vane pump having the discharge inner portion 800 that is not formed
with the discharge inner recess 802. In other words, discharge
pressure can be reduced in an initial phase of a discharge stroke
because the opening area of the discharge port is increased in the
initial phase of the discharge stroke. This can suppress backflow
of oil from the discharge port into the pump chambers, making it
possible to discharge a larger amount of oil in the initial phase
of the discharge stroke. This in turn makes it possible to
completely discharge air bubbles (air) even if air bubbles (air)
are contained in the oil within the pump chambers. As a result, a
larger amount of oil can be suctioned in a suction stroke following
the discharge stroke.
[0164] In the above fifth embodiment, the portion of the discharge
inner recess 802 of the discharge inner portion 800 that is most
depressed toward the rotation center C is at the same distance from
the rotation center C as the distance from the rotation center C to
the end of the rotor recess 24 of the rotor 20 in the rotational
axis direction. However, the present invention is not limited to
this embodiment. The portion of the discharge inner recess 802 most
depressed toward the rotation center C may be depressed closer to
the rotation center C than the end of the rotor recess 24 of the
rotor 20 in the rotational axis direction. This increases the
opening area of the discharge port further and thus increases
discharge efficiency.
<Modification of the Rotor Recess 24>
[0165] In the above first to fifth embodiments, the size of the
rotor recess 24 in the rotational axis direction is smaller than
the size of the first suction recess 431 and the first suction
recess 441 of the cam ring 40 in the rotational axis direction.
However, the present invention is not limited to these
embodiments.
[0166] FIG. 19 depicts a modification of the rotor recess 24 of the
rotor 20.
[0167] As shown in FIG. 19, the size of the rotor recess 24 in the
rotational axis direction may be larger than the size of the first
suction recess 431 and the first suction recess 441 of the cam ring
40 in the rotational axis direction. For example, the size of the
rotor recess 24 in the rotational axis direction may be increased
while the size thereof in the direction toward the rotation center
C at the end of the rotor 20 in the rotational axis direction is
kept the same as that of the rotor recess 24 of the first to fifth
embodiments. This increases the volume of the recess depressed from
the curved surface portion 22 toward the rotation center C as
compared to that of the rotor 20 of the first to fifth embodiments.
This in turn can increase the amount of oil suctioned into the pump
chambers, and thus suppress an excessive decrease in the amount of
oil suctioned into the pump chambers that may otherwise occur due
to the outer periphery of the rotor 20 having the arc-like curved
surface portion 22 centered on the rotation center C.
[0168] The rotor recesses 24 formed at the respective ends of the
rotor 20 in the rotational axis direction may be made continuous
with each other. That is, the two rotor recesses 24 may share the
same end on the side closer to the outer peripheral surface (curved
surface portion 22) of the rotor 20. In other words, both ends of
the two rotor recesses 24 on the side closer to the outer
peripheral surface of the rotor 20 may be at the center of the
rotor 20 in the rotational axis direction. This maximizes the
volume of the recess depressed toward the rotation center C from
the curved surface portion 22.
<Modification of the Curved Surface Portion 22>
[0169] FIG. 20 depicts a modification of the curved surface portion
22 of the rotor 20.
[0170] In the above first to fifth embodiments, the curved surface
portion 22 of the rotor 20 may be formed with a communication
portion 222 depressed from the curved surface portion 22 toward the
rotation center C so as to provide communication between the two
rotor recesses 24 formed at the respective ends of the rotor 20 in
the rotational axis direction. By way of example, the communication
portion 222 is formed so as to extend in the rotational axis
direction at the center of the curved surface portion 22 in the
circumferential direction.
[0171] Providing the communication portion 222 communicating the
two rotor recesses 24 with each other allows air that collects
toward the rotor 20 during rotation by centrifugal force to be
guided into the communication portion 222, and this improves
efficiency of air discharge into the discharge port in a discharge
section. This configuration also improves efficiency of air
discharge from the pump chambers, helping suppress fluctuation in
pressure and occurrence of noise.
REFERENCE SIGNS LIST
[0172] 1, 702, 703, 704, 705 . . . Vane pump [0173] 2 . . . First
suction port [0174] 3 . . . Second suction port [0175] 4 . . .
First discharge port [0176] 5 . . . Second discharge port [0177] 10
. . . Rotary shaft [0178] 20 . . . Rotor [0179] 22 . . . Curved
surface portion [0180] 24 . . . Rotor recess [0181] 30 . . . Vane
[0182] 40 . . . Cam ring [0183] 50 . . . Inner plate [0184] 60 . .
. Outer plate [0185] 100 . . . Housing [0186] 110 . . . Case [0187]
120 . . . Cover [0188] 710, 720, 730, 740 . . . Suction inner
portion [0189] 712, 722, 732, 742 . . . Suction inner recess [0190]
800 . . . Discharge inner portion [0191] 802 . . . Discharge inner
recess
* * * * *