U.S. patent application number 15/758091 was filed with the patent office on 2018-09-06 for vane pump.
This patent application is currently assigned to KYB Corporation. The applicant listed for this patent is KYB Corporation. Invention is credited to Tomoyuki FUJITA, Hirotoshi KONDOU, Tomoyuki NAKAGAWA, Hiromi SHIMONO.
Application Number | 20180252215 15/758091 |
Document ID | / |
Family ID | 58239573 |
Filed Date | 2018-09-06 |
United States Patent
Application |
20180252215 |
Kind Code |
A1 |
SHIMONO; Hiromi ; et
al. |
September 6, 2018 |
VANE PUMP
Abstract
A vane pump includes a high-pressure chamber formed as a groove
in a bottom portion of a pump-accommodating concave portion. The
working fluid is discharged from a plurality of discharge ports
leading to the high-pressure chamber. A high-pressure passage has
an opening portion opening to the high-pressure chamber and guides
the working fluid to the outside of the high-pressure chamber. In
the vane pump, one of the plurality of discharge ports is arranged
so as to face the opening portion of the high-pressure passage, and
the flow-passage cross-sectional area of the high-pressure chamber
is smaller than the total flow-passage cross-sectional area of the
plurality of the discharge ports.
Inventors: |
SHIMONO; Hiromi; (Gifu,
JP) ; FUJITA; Tomoyuki; (Gifu, JP) ; NAKAGAWA;
Tomoyuki; (Gifu, JP) ; KONDOU; Hirotoshi;
(Gifu, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KYB Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
KYB Corporation
Tokyo
JP
|
Family ID: |
58239573 |
Appl. No.: |
15/758091 |
Filed: |
August 31, 2016 |
PCT Filed: |
August 31, 2016 |
PCT NO: |
PCT/JP2016/075509 |
371 Date: |
March 7, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 15/06 20130101;
F04C 15/00 20130101; F04C 2/344 20130101 |
International
Class: |
F04C 15/06 20060101
F04C015/06; F04C 2/344 20060101 F04C002/344 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 2015 |
JP |
2015-179525 |
Claims
1. A vane pump comprising: a rotor linked to a driving shaft and
having a plurality of vanes on an outer circumference thereof; a
cam ring configured to accommodate the rotor and define pump
chambers in a space therein; a pump body provided with a
pump-accommodating concave portion into which the rotor and the cam
ring are accommodated; a side plate provided between the rotor and
the pump body; a plurality of discharge ports formed in the side
plate and configured to discharge working fluid from the pump
chambers; a high-pressure chamber in a form of a groove formed in a
bottom portion of the pump-accommodating concave portion, the
working fluid discharged from the plurality of discharge ports
being led to the high-pressure chamber; and a high-pressure passage
having an opening portion opening to the high-pressure chamber, the
high-pressure passage being configured to guide the working fluid
to outside of the high-pressure chamber, wherein one of the
plurality of discharge ports is arranged so as to face the opening
portion of the high-pressure passage, and a flow-passage
cross-sectional area of the high-pressure chamber is smaller than a
total flow-passage cross-sectional area of the plurality of
discharge ports.
2. The vane pump according to claim 1, wherein the plurality of
discharge ports includes a first discharge port and a second
discharge port, the first discharge port being arranged so as to
face the opening portion of the high-pressure passage and the
second discharge port being arranged at a position remote from the
opening portion of the high-pressure passage, the high-pressure
chamber is formed in an annular shape such that a flow of the
working fluid that has been guided from the second discharge port
to the high-pressure chamber is divided into two flows flowing into
a first high-pressure chamber and a second high-pressure chamber in
the high-pressure chamber, and thereafter, the flows are mixed at
the opening portion of the high-pressure passage, and a total
flow-passage cross-sectional area of the first high-pressure
chamber and the second high-pressure chamber is larger than a
flow-passage cross-sectional area of the second discharge port.
Description
TECHNICAL FIELD
[0001] The present invention relates to a vane pump.
BACKGROUND ART
[0002] JP2002-161869A discloses a balanced vane pump having two
discharge ports at symmetrical positions. Discharged oil discharged
from these two discharge ports flows through an annular pressure
chamber provided in a housing and flows into a flow passage
connected to a flow-amount control valve.
SUMMARY OF INVENTION
[0003] However, in the vane pump described in JP2002-161869A, flows
of the discharged oil that have been discharged from the two
discharge ports are mixed in the pressure chamber, and thereafter,
the mixed flow of the discharged oil flows into the flow passage
connected to the flow-amount control valve. In the vane pump of
this type, in order to reduce pressure loss of the discharged oil
mixed in the pressure chamber, the flow-passage cross-sectional
area of the pressure chamber needs to be equal to or greater than
the total flow-passage cross-sectional area of the two discharge
ports. Thus, it is difficult to make the flow-passage
cross-sectional area of the pressure chamber smaller, and to reduce
the size of the vane pump.
[0004] The present invention has been conceived in light of the
problems mentioned above, and an object thereof is to reduce the
size of a vane pump.
[0005] According to a certain aspect of the present invention, a
vane pump includes: a rotor linked to a driving shaft and having a
plurality of vanes on an outer circumference thereof; a cam ring
configured to accommodate the rotor and define pump chambers in a
space therein; a pump body provided with a pump-accommodating
concave portion into which the rotor and the cam ring are
accommodated; a side plate provided between the rotor and the pump
body; a plurality of discharge ports formed in the side plate and
configured to discharge working fluid from the pump chambers; a
high-pressure chamber in a form of a groove formed in a bottom
portion of the pump-accommodating concave portion, the working
fluid discharged from the plurality of discharge ports being led to
the high-pressure chamber; and a high-pressure passage having an
opening portion opening to the high-pressure chamber, the
high-pressure passage being configured to guide the working fluid
to outside of the high-pressure chamber, wherein one of the
plurality of discharge ports is arranged so as to face the opening
portion of the high-pressure passage, and a flow-passage
cross-sectional area of the high-pressure chamber is smaller than a
total flow-passage cross-sectional area of the plurality of
discharge ports.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 is a sectional view of a vane pump according to an
embodiment of the present invention.
[0007] FIG. 2 is a plan view showing a bottom portion of a
pump-accommodating concave portion of the vane pump according to
the embodiment of the present invention.
DESCRIPTION OF EMBODIMENT
[0008] A vane pump 100 according to an embodiment of the present
invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing a cross section of the vane pump
100, cut in parallel to a driving shaft.
[0009] The vane pump 100 is used as a fluid pressure source for a
fluid pressure apparatus mounted on a vehicle, such as, for
example, a power steering apparatus, a transmission, or the like.
Oil, aqueous alternative fluid of other types, or the like may be
used as working fluid.
[0010] In the vane pump 100, motive force from an engine (not
shown) is transmitted to an end portion of a driving shaft 1, and a
rotor 2 linked to the driving shaft 1 is rotated.
[0011] The vane pump 100 includes a plurality of vanes 3 provided
in the rotor 2 so as to be capable of reciprocating in the radial
direction of the rotor 2, and a cam ring 4 that accommodates the
rotor 2 therein such that tip-end portions of the vanes 3 slide on
a cam face 4a on the inner circumference of the cam ring 4 by
rotation of the rotor 2.
[0012] In the rotor 2, slits having openings on an outer
circumferential surface of the rotor 2 are formed in a radiating
pattern with predetermined gaps therebetween, and the vanes 3 are
respectively inserted into the slits in a freely slidable manner.
At the base-end sides of the slits, back pressure chambers 17 into
which discharge pressure of the pump is guided are defined. The
vanes 3 are pushed by the pressure in the back pressure chambers 17
in the directions in which the vanes 3 are drawn out from the
slits, and the tip-end portions of the vanes 3 are brought into
contact with the cam face 4a on the inner circumference of the cam
ring 4. With such a configuration, a plurality of pump chambers 7
are defined in the cam ring 4 by the outer surface of the rotor 2,
the cam face 4a of the cam ring 4, and the adjacent vanes 3.
[0013] The cam ring 4 is an annular member of which the cam face 4a
on the inner circumference has an oval shape, and the cam ring 4
has suction regions in which volumes of the pump chambers 7
partitioned by and between the respective vanes 3, which slide on
the cam face 4a by the rotation of the rotor 2, are expanded and
discharge regions in which volumes of the pump chambers 7 are
contracted. The respective pump chambers 7 are expanded/contracted
by the rotation of the rotor 2. The vane pump 100 is a so-called
balanced vane pump in which the cam ring 4 has two suction regions
and two discharge regions.
[0014] A pump cover 5 is arranged so as to be in contact with one
side surfaces of the rotor 2 and the cam ring 4 on the one side
(upper side in FIG. 1), and a side plate 6 is arranged so as to be
in contact with the other side surfaces of the rotor 2 and the cam
ring 4 on the other side (lower side in FIG. 1). As described
above, the pump cover 5 and the side plate 6 are arranged in such a
manner that both side surfaces of the rotor 2 and the cam ring 4
are sandwiched, and thereby, the pump chambers 7 are sealed.
[0015] At the surface of the pump cover 5 on which the rotor 2
slides, two arc-shaped suction ports 8 that open so as to
correspond to the suction regions of the cam ring 4 and that guide
working oil as the working fluid to the pump chambers 7 are formed
so as to form grooves.
[0016] In the side plate 6, a pair of an arc-shaped first discharge
port 9a and an arc-shaped second discharge port 9b are formed so as
to penetrate through the side plate 6. The first discharge port 9a
and the second discharge port 9b are formed so as to open
correspondingly to the discharge regions of the cam ring 4 and
discharge the working oil that has been discharged from the pump
chambers 7 to a high-pressure chamber 12.
[0017] As the rotor 2 is rotated, the respective pump chambers 7
suck the working oil through the suction ports 8 in the suction
regions of the cam ring 4 and discharge the working oil through the
first discharge port 9a and the second discharge port 9b in the
discharge regions of the cam ring 4. As described above, the
respective pump chambers 7 supply/discharge the working oil by the
expansion/contraction due to the rotation of the rotor 2.
[0018] The driving shaft 1 is rotatably supported by a pump body 10
via a bush 26. A pump-accommodating concave portion 10a for
accommodating the rotor 2, the cam ring 4, and the side plate 6 is
formed in the pump body 10.
[0019] An annular groove portion 15 is formed in a bottom portion
of the pump-accommodating concave portion 10a. The side plate 6 is
arranged on the bottom portion of the pump-accommodating concave
portion 10a, and the annular high-pressure chamber 12 is defined by
the groove portion 15 and the side plate 6. The working oil that
has been discharged from the pump chambers 7 through the first
discharge port 9a and the second discharge port 9b is guided into
the high-pressure chamber 12. The driving shaft 1 penetrates
through the side plate 6.
[0020] The cam ring 4 is accommodated in the pump-accommodating
concave portion 10a so as to be stacked on the side plate 6. The
pump cover 5 is fastened to an end surface 10c of an annular skirt
10b of the pump body 10, and thereby, the pump-accommodating
concave portion 10a is sealed by the pump cover 5.
[0021] The side plate 6 is provided with two positioning pins 14
that penetrate through concave portions (not shown) formed on an
outer circumferential surface of the cam ring 4 and inserted into
pin holes 5a of the pump cover 5. With the positioning pins 14,
relative rotation of the pump cover 5 and the side plate 6 with
respect to the cam ring 4 is restricted, thereby achieving
positioning of the suction ports 8 of the pump cover 5 to the
suction regions of the cam ring 4 and positioning of the first
discharge port 9a and the second discharge port 9b of the side
plate 6 to the discharge regions of the cam ring 4.
[0022] In addition, in the pump body 10, a suction passage 11 that
communicates with the suction ports 8 and guides the working oil to
the suction ports 8 and a discharge passage 13 that communicates
with the high-pressure chamber 12 and supplies the working oil in
the high-pressure chamber 12 to an external hydraulic apparatus
through a high-pressure passage 19 are formed.
[0023] A flow-amount control valve 20 (see FIG. 2) for controlling
the flow amount of the working oil supplied to the hydraulic
apparatus is interposed in the discharge passage 13. The
flow-amount control valve 20 is accommodated in an assembly hole 18
formed in the pump body 10.
[0024] The working oil in the high-pressure chamber 12 is guided to
the flow-amount control valve 20 through the high-pressure passage
19 formed in the pump body 10. The high-pressure passage 19 has an
opening portion 19a that opens to the high-pressure chamber 12 and
an exit portion 19b that opens to the assembly hole 18.
[0025] Next, the high-pressure chamber 12 and the high-pressure
passage 19 will be described in detail with reference to FIG. 2.
FIG. 2 is a plan view of the pump body 10 viewed from the direction
of an arrow A in FIG. 1, and is a diagram showing a state in which
the pump-accommodating concave portion 10a is empty.
[0026] As shown in FIG. 2, in the bottom portion of the
pump-accommodating concave portion 10a, the annular groove portion
15 is formed so as to surround the periphery of an insert hole 1a
into which the driving shaft 1 is inserted. The groove portion 15
may be formed in an arc shape.
[0027] The side plate 6 is mounted on an annular step portion 10d
forming an outer edge of the bottom portion of the
pump-accommodating concave portion 10a, thereby sealing the groove
portion 15 and defining the high-pressure chamber 12. The first
discharge port 9a and the second discharge port 9b of the side
plate 6 open to the high-pressure chamber 12 and guide the working
oil that has been discharged from the pump chambers 7 to the
high-pressure chamber 12. The first discharge port 9a and the
second discharge port 9b are formed so as to face each other with
the driving shaft 1 located therebetween. The working oil that has
been guided to the high-pressure chamber 12 through the first
discharge port 9a and the second discharge port 9b flows into the
high-pressure passage 19 from the opening portion 19a.
[0028] As shown in FIG. 2, of the first discharge port 9a and the
second discharge port 9b, the first discharge port 9a is arranged
so as to face the opening portion 19a of the high-pressure passage
19. By arranging the first discharge port 9a as described above,
the working oil that has been guided from the first discharge port
9a to the high-pressure chamber 12 crosses the high-pressure
chamber 12 and flows directly into the high-pressure passage 19. On
the other hand, the second discharge port 9b is arranged at a
position remote from the opening portion 19a of the high-pressure
passage 19. By arranging the second discharge port 9b as described
above, the flow of the working oil that has been guided from the
second discharge port 9b to the high-pressure chamber 12 is divided
into two flows flowing into a first high-pressure chamber 12a and a
second high-pressure chamber 12b, through which the second
discharge port 9b is communicated with the opening portion 19a of
the high-pressure passage 19 along the circumferential direction at
the left side and the right side in FIG. 2, respectively.
Subsequently, the flows of the working oil in the first
high-pressure chamber 12a and the second high-pressure chamber 12b
are mixed at the opening portion 19a of the high-pressure passage
19, and the mixed flow flows into the high-pressure passage 19. As
described above, only the working oil that has been discharged from
the second discharge port 9b flows through the high-pressure
chamber 12. Therefore, in order to reduce pressure loss of the
working oil, which has been discharged through the second discharge
port 9b, caused by the high-pressure chamber 12, it suffices to
ensure that the total flow-passage cross-sectional area of the
first high-pressure chamber 12a and the second high-pressure
chamber 12b is greater than the flow-passage cross-sectional area
of the second discharge port 9b. Therefore, it is possible to make
the flow-passage cross-sectional area of the high-pressure chamber
12 smaller than the total flow-passage cross-sectional area of the
first discharge port 9a and the second discharge port 9b.
[0029] In a case in which the high-pressure chamber 12 is formed in
an arc shape, in other words, for example, in a case in which the
high-pressure chamber 12 is constituted of the first high-pressure
chamber 12a only, it suffices to ensure that the flow-passage
cross-sectional area of the high-pressure chamber 12 (the first
high-pressure chamber 12a) is greater than the flow-passage
cross-sectional area of the second discharge port 9b.
[0030] According to the embodiment mentioned above, the advantages
described below are afforded.
[0031] In the vane pump 100, the first discharge port 9a is
arranged so as to face the opening portion 19a of the high-pressure
passage 19. With this configuration, the working oil that has been
guided from the first discharge port 9a to the high-pressure
chamber 12 crosses the high-pressure chamber 12 and flows directly
into the high-pressure passage 19. Thus, because only the working
oil that has been guided through the second discharge port 9b flows
through the high-pressure chamber 12, it is possible to make the
flow-passage cross-sectional area of the high-pressure chamber 12
smaller than the total flow-passage cross-sectional area of the
first discharge port 9a and the second discharge port 9b.
Accordingly, even when the depth of the groove portion 15 is
reduced and the flow-passage cross-sectional area of the
high-pressure chamber 12 is reduced compared with those of a
conventional vane pump, it is possible to ensure the required
flow-passage cross-sectional area of the high-pressure chamber 12.
Therefore, it is possible to reduce the size of the vane pump
100.
[0032] In addition, in a case in which the high-pressure chamber 12
is formed in an annular shape, because the working oil that has
been guided from the second discharge port 9b to the high-pressure
chamber 12 flows by being divided into two flows flowing into the
first high-pressure chamber 12a and the second high-pressure
chamber 12b, as compared with a case in which the high-pressure
chamber 12 is formed in the arc shape (a case in which only the
first high-pressure chamber 12a is formed), it is possible to make
respective flow-passage cross-sectional areas of the first
high-pressure chamber 12a and the second high-pressure chamber 12b
smaller. Accordingly, it is possible to further reduce the size of
the vane pump.
[0033] The configurations, operations, and effects of the
embodiment of the present invention configured as described above
will be collectively described.
[0034] The vane pump 100 includes the rotor 2 that is linked to the
driving shaft 1 and has the plurality of vanes 3 on the outer
circumference thereof, the cam ring 4 that accommodates the rotor 2
and defines the pump chambers 7 in a space therein, the pump body
10 that is provided with the pump-accommodating concave portion 10a
into which the rotor 2 and the cam ring 4 are accommodated, the
side plate 6 that is provided between the rotor 2 and the pump body
10, a plurality of discharge ports (the first discharge port 9a and
the second discharge port 9b) that are formed in the side plate 6
and discharge the working fluid from the pump chambers 7, the
high-pressure chamber 12 that is formed in a form of a groove in
the bottom portion of the pump-accommodating concave portion 10a,
the working fluid is discharged from the plurality of discharge
ports (the first discharge port 9a and the second discharge port
9b) being led to the high-pressure chamber 12, and the
high-pressure passage 19 that has the opening portion 19a opening
to the high-pressure chamber 12 and guides the working fluid to the
outside of the high-pressure chamber 12. In the vane pump 100, one
(the first discharge port 9a) of the plurality of discharge ports
(the first discharge port 9a and the second discharge port 9b) is
arranged so as to face the opening portion 19a of the high-pressure
passage 19, and the flow-passage cross-sectional area of the
high-pressure chamber 12 is smaller than the total flow-passage
cross-sectional area of the plurality of discharge ports (the first
discharge port 9a and the second discharge port 9b).
[0035] In this configuration, of the first discharge port 9a and
the second discharge port 9b, the first discharge port 9a is
arranged so as to face the opening portion 19a of the high-pressure
passage 19. Therefore, the working fluid that has been discharged
from the first discharge port 9a flows directly into the
high-pressure passage 19. Accordingly, because only the working oil
that has been guided through the second discharge port 9b flows
through the high-pressure chamber 12, it is possible to make the
flow-passage cross-sectional area of the high-pressure chamber 12
smaller than the total flow-passage cross-sectional area of the
first discharge port 9a and the second discharge port 9b.
Therefore, it is possible to reduce the size of the vane pump
100.
[0036] In addition, in the vane pump 100, the plurality of
discharge ports (the first discharge port 9a and the second
discharge port 9b) include the first discharge port 9a that is
arranged so as to face the opening portion 19a of the high-pressure
passage 19 and the second discharge port 9b that is arranged at a
position remote from the opening portion 19a of the high-pressure
passage 19; the high-pressure chamber 12 is formed in an annular
shape such that the flow of the working fluid that has been guided
from the second discharge port 9b to the high-pressure chamber 12
is divided into two flows flowing into the first high-pressure
chamber 12a and the second high-pressure chamber 12b in the
high-pressure chamber 12, and thereafter, the flows are mixed at
the opening portion 19a of the high-pressure passage 19; and the
total flow-passage cross-sectional area of the first high-pressure
chamber 12a, and the second high-pressure chamber 12b is larger
than the flow-passage cross-sectional area of the second discharge
port 9b.
[0037] In this configuration, the total flow-passage
cross-sectional area of the first high-pressure chamber 12a and the
second high-pressure chamber 12b is larger than the flow-passage
cross-sectional area of the second discharge port 9b. Accordingly,
it is possible to reduce the pressure loss of the working oil,
which has been discharged through the second discharge port 9b,
caused by the high-pressure chamber 12. In addition, because the
flow of the working fluid that has been guided from the second
discharge port 9b to the high-pressure chamber 12 is divided into
two flows flowing into the first high-pressure chamber 12a and the
second high-pressure chamber 12b, it is possible to make the
respective flow-passage cross-sectional areas of the first
high-pressure chamber 12a and the second high-pressure chamber 12b
small. Accordingly, it is possible to further reduce the size of
the vane pump 100.
[0038] Embodiments of this invention were described above, but the
above embodiments are merely examples of applications of this
invention, and the technical scope of this invention is not limited
to the specific constitutions of the above embodiments.
[0039] For example, there may be three or more discharge ports as
the plurality of discharge ports, as long as one of them is
arranged so as to face the high-pressure passage 19. In addition,
in the above-mentioned embodiment, although the vane pump 100
includes the flow-amount control valve 20, the vane pump 100 may
have a configuration in which the flow-amount control valve 20 is
not included.
[0040] This application claims priority based on Japanese Patent
Application No. 2015-179525 filed with the Japan Patent Office on
Sep. 11, 2015, the entire contents of which are incorporated into
this specification.
* * * * *