WO2017077773A1

WO2017077773A1 - Vane pump

Info

Publication number: WO2017077773A1
Application number: PCT/JP2016/077586
Authority: WO
Inventors: 善也中村; 新司矢加部; 鈴木　一成; 浩一朗赤塚; 博仁渡辺
Original assignee: Ｋｙｂ株式会社
Priority date: 2015-11-02
Filing date: 2016-09-16
Publication date: 2017-05-11
Also published as: JP2017089396A; DE112016005023T5; JP6220837B2; US20180306184A1; CN108350878A

Abstract

A vane pump 100 is provided with: a rotor 20; a plurality of vanes 30; a cam ring 40; a second side plate 80; a suction port 81 provided in the second side plate 80 and conducting operating oil to a pump chamber 41; a pump cover 60 disposed so that the second side plate 80 will be sandwiched between the pump cover 60 and the cam ring 40; and a low-pressure chamber 61 formed in the pump cover 60 and having an opening 62 in communication with the suction port 81. The suction port 81 is disposed offset forward in the direction of rotation of the rotor 20 from the opening 62 of the low-pressure chamber 61.

Description

Vane pump

The present invention relates to a vane pump.

JP2014-74368A discloses a vane pump including a rotor that is rotationally driven, a plurality of vanes provided in the rotor, and a cam ring that houses the rotor. The vane reciprocates with the rotation of the rotor, and the tip of the vane is in sliding contact with the inner peripheral cam surface of the cam ring. A pair of side plates are provided on both sides of the rotor and the cam ring, and a pump chamber partitioned by a plurality of vanes is defined between the rotor and the cam ring by the pair of side plates.

The vane pump disclosed in JP2014-74368A further includes a pump cover arranged with one side plate between the cam ring and the cam ring. A low pressure chamber is formed by the pump cover, and one side plate is provided with a suction port. The working fluid is sucked into the pump chamber from the low pressure chamber through the suction port.

In a vane pump, the pump chamber rotates with the vane. Therefore, the working fluid in the low-pressure chamber is not easily filled in the front portion in the rotational direction of the pump chamber when sucked into the pump chamber. Therefore, as the rotation of the pump becomes faster, the working fluid does not easily reach the front part in the rotational direction of the pump chamber due to the retention of the working fluid. As a result, the working fluid is insufficient with respect to the volume of the pump chamber, and cavitation may occur. For these reasons, there is a need for a vane pump having better suction characteristics.

The present invention aims to improve the suction characteristics of the vane pump.

According to an aspect of the present invention, a vane pump includes a rotor that is rotationally driven, a plurality of vanes that are provided in the rotor so as to be capable of reciprocating in the radial direction of the rotor, and a plurality of vanes that are accommodated as the rotor rotates. A cam ring having an inner circumferential cam surface with which the tip of the vane slides, a side member that abuts the end surface of the cam ring and defines a pump chamber partitioned by a plurality of vanes between the rotor and the cam ring; and the side member, A suction port that guides the working fluid to the pump chamber, a cover member that is disposed with a side member sandwiched between the cam ring, and a low-pressure chamber that is formed in the cover member and has an opening that communicates with the suction port. The suction port is disposed so as to be shifted forward in the rotational direction of the rotor with respect to the opening of the low pressure chamber.

FIG. 1 is a cross-sectional view of a vane pump according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a plan view of the rotor, the vane, and the cam ring as viewed from the pump cover side. FIG. 4 is a cross-sectional view of the cam ring and the first and second side plates. FIG. 5 is a plan view of the first side plate as viewed from the cam ring side. FIG. 6 is a plan view of the second side plate as viewed from the cam ring side. FIG. 7 is a plan view of the rotor, vane, cam ring, and second side plate as seen from the pump body side. FIG. 8 is a plan view of the rotor, the vane, the cam ring, and the second side plate as viewed from the pump body side, and the low pressure chamber is indicated by a two-dot chain line. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. FIG. 10 is a cross-sectional view of a vane pump according to another embodiment of the present invention, corresponding to FIG.

Hereinafter, a vane pump 100 according to an embodiment of the present invention will be described with reference to the drawings. Here, although the vane pump 100 in which working oil is used as the working fluid will be described, other fluids such as working water may be used as the working fluid.

1 and 2 are cross-sectional views of the vane pump 100. FIG. 1 is a cross-sectional view taken along the line II in FIG. 2, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. The vane pump 100 is used as a hydraulic pressure supply source of a hydraulic device 1 (for example, a power steering device or a transmission) mounted on a vehicle.

The vane pump 100 includes a drive shaft 10, a rotor 20 connected to the drive shaft 10, a plurality of vanes 30 provided in the rotor 20, and a cam ring 40 that accommodates the rotor 20 and the vanes 30.

The drive shaft 10 is rotatably supported by the pump body 50 and the pump cover (cover member) 60. When the power of the engine or the electric motor (not shown) is transmitted to the drive shaft 10, the rotor 20 rotates as the drive shaft 10 rotates.

Hereinafter, the rotation center axis direction of the rotor 20 is also simply referred to as “axial direction”, the radial direction of the rotor 20 is also simply referred to as “radial direction”, and the rotation direction of the rotor 20 is also simply referred to as “rotational direction”.

FIG. 3 is a plan view of the rotor 20, the vane 30, and the cam ring 40 as viewed from the pump cover 60 side. As shown in FIG. 3, a plurality of slits 22 having openings 21 on the outer peripheral surface are radially formed on the rotor 20 at predetermined intervals. The opening 21 of the slit 22 is formed in a raised portion 23 that protrudes radially outward from the outer periphery of the rotor 20. In other words, the protruding portions 23 are formed on the outer periphery of the rotor 20 by the number of the slits 22. A back pressure chamber 24 is defined by the vane 30 in the slit 22.

The vanes 30 are slidably inserted into the slits 22 and reciprocate in the radial direction as the rotor 20 rotates. The distal end portion 31 of the vane 30 faces the inner peripheral surface 40 a of the cam ring 40, and the proximal end portion 32 of the vane 30 faces the back pressure chamber 24.

作動 Hydraulic oil is guided to the back pressure chamber 24. The vane 30 is pressed in a direction protruding from the slit 22 by the pressure of the hydraulic oil in the back pressure chamber 24, and the tip portion 31 of the vane 30 is in contact with the inner peripheral surface 40 a of the cam ring 40.

Refer to FIGS. 1 and 2 again. The vane pump 100 further includes first and

second side plates

70 and 80 as first and second side members disposed with the rotor 20 and the cam ring 40 sandwiched in the axial direction.

FIG. 4 is a cross-sectional view of the cam ring 40 and the first and

second side plates

70 and 80. In FIG. 4, a high pressure chamber 53, a passage 54, and a low pressure chamber 61, which will be described later, are indicated by a two-dot chain line.

As shown in FIG. 4, the first and

second side plates

70 and 80 have

side surfaces

70 a and 80 a that contact the rotor 20 and the cam ring 40, respectively, and are partitioned by the vane 30 between the rotor 20 and the cam ring 40. The pump chamber 41 is partitioned.

As shown in FIG. 3, the inner peripheral surface 40a of the cam ring 40 is formed in a substantially oval shape. Hereinafter, the inner peripheral surface 40a may be referred to as an “inner peripheral cam surface 40a”.

Since the inner circumferential cam surface 40a of the cam ring 40 is formed in a substantially oval shape, the vane 30 reciprocates with respect to the rotor 20 as the rotor 20 rotates, and the pump chamber 41 repeats expansion and contraction. When the pump chamber 41 expands, the hydraulic oil is sucked into the pump chamber 41, and when the pump chamber 41 contracts, the hydraulic oil is discharged from the pump chamber 41.

In this embodiment, the vane 30 reciprocates twice while the rotor 20 makes one rotation, and the pump chamber 41 repeats expansion and contraction twice. That is, the vane pump 100 alternately has two

expansion regions

42a and 42c in which the pump chamber 41 expands and two

contraction regions

42b and 42d in which the pump chamber 41 contracts in the rotation direction.

As shown in FIGS. 1 and 2, the pump body 50 is formed with a housing recess 51 for housing the rotor 20, the cam ring 40 and the first side plate 70. The first side plate 70 is disposed on the bottom surface 51 a of the housing recess 51.

An annular groove 52 is formed on the bottom surface 51 a of the housing recess 51. The annular groove 52 and the first side plate 70 define a high pressure chamber 53 into which hydraulic oil discharged from the pump chamber 41 flows. The high pressure chamber 53 is connected to the hydraulic device 1, and hydraulic oil discharged from the pump chamber 41 is supplied to the hydraulic device 1 through the high pressure chamber 53.

FIG. 5 is a plan view of the first side plate 70 viewed from the cam ring 40 side. As shown in FIGS. 4 and 5, the first side plate 70 is formed in an annular shape having a hole 71 at the center thereof. The drive shaft 10 (see FIG. 1) is inserted through the hole 71.

The first side plate 70 is provided with two discharge ports 72 that guide the hydraulic oil discharged from the pump chamber 41 to the high-pressure chamber 53. The discharge port 72 is located in each

contraction region

42b, 42d. Therefore, the hydraulic oil in the pump chamber 41 is discharged from the high-pressure chamber 53 through the discharge port 72 when the pump chamber 41 passes through the

contraction regions

42b and 42d.

Also, two back pressure passages 73 are formed in the first side plate 70 to guide the hydraulic oil from the high pressure chamber 53 to the back pressure chamber 24. The back pressure passage 73 has an arc shape centered on the hole 71 and is located in the

expansion regions

42a and 42c. Therefore, hydraulic oil is guided from the high pressure chamber 53 to the back pressure chamber 24 that passes through the

expansion regions

42 a and 42 c. As a result, the vane 30 passing through the

expansion regions

42a and 42c is pressed in a direction protruding from the slit 22 (see FIG. 3) by the pressure in the back pressure chamber 24.

Thus, the vane 30 is pressed in the direction protruding from the slit 22 by the pressure in the back pressure chamber 24 and the centrifugal force generated by the rotation of the rotor 20.

Refer to FIGS. 1 and 2 again. The housing recess 51 of the pump body 50 is formed larger than the cam ring 40, and a passage 54 is defined by the cam ring 40 and the pump body 50. The passage 54 extends from the outer periphery of the second side plate 80 to the outer periphery of the first side plate 70.

The opening of the housing recess 51 is sealed by the pump cover 60. The pump cover 60 is fastened to the pump body 50 by bolts (not shown). A second side plate 80 is disposed between the pump cover 60 and the cam ring 40.

The pump cover 60 forms a low pressure chamber 61 connected to the tank 2. The low pressure chamber 61 communicates with a low pressure passage 55 formed in the pump body 50. The hydraulic oil in the tank 2 is supplied to the low pressure chamber 61 through the low pressure passage 55.

Further, the low pressure chamber 61 has an opening 62 that communicates with the passage 54 and communicates with the suction port 81 provided in the second side plate 80. The passage 54 communicates with a suction port 74 that guides hydraulic oil to the pump chamber 41. That is, the hydraulic oil in the low pressure chamber 61 is guided to the pump chamber 41 through the passage 54 and the suction port 74.

In this embodiment, as shown in FIGS. 4 and 5, the suction port 74 is formed by a recess 75 formed on the side surface 70 a of the first side plate 70 and an end surface 40 b of the cam ring 40 facing the recess 75. Partitioned. For example, the suction port 74 may include a hole penetrating the first side plate 70.

6 is a plan view of the second side plate 80 as viewed from the cam ring 40 side, and FIG. 7 is a plan view of the rotor 20, the vane 30, the cam ring 40, and the second side plate 80 as viewed from the pump body 50 side. .

As shown in FIG. 4, FIG. 6, and FIG. 7, the second side plate 80 has two hollow portions 82 formed on the outer peripheral surface 80b. The recess 82 communicates with the pump chamber 41 through an opening 83 a formed in the side surface 80 a of the second side plate 80. Further, the recess 82 communicates with the low pressure chamber 61 through an opening 83b formed in the side surface 80c of the second side plate 80 on the side opposite to the side surface 80a.

The hollow portion 82 is located in each of the

expansion regions

42a and 42c. Therefore, when the pump chamber 41 passes through the

expansion regions

42 a and 42 c, the working oil is guided from the low pressure chamber 61 to the pump chamber 41 through the recess 82.

Thus, the suction port 81 is partitioned by the recess 82 and the end surface 40c of the cam ring 40 facing the recess 82, and the flow of hydraulic oil from the low pressure chamber 61 is axially directed (from the second side plate 80 to the cam ring). The hydraulic oil is guided to the pump chamber 41 in the direction toward 40).

The suction port 81 is not limited to the form defined by the recessed part 82 and the end face 40c of the cam ring 40. For example, the suction port 81 may be formed by a hole penetrating the second side plate 80.

FIG. 8 is a plan view of the rotor 20, the vane 30, the cam ring 40, and the second side plate 80 as viewed from the pump body 50 side, and the low pressure chamber 61 is indicated by a two-dot chain line. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. In FIG. 9, the rotor 20 and the vane 30 are not shown.

As shown in FIGS. 8 and 9, the

openings

83 a and 83 b of the suction port 81 are formed so that the width in the rotation direction is substantially equal to the opening 62 of the low-pressure chamber 61. The

openings

83 a and 83 b are located on the front side in the rotational direction with respect to the opening 62 of the low pressure chamber 61. That is, the suction port 81 is arranged so as to be shifted forward in the rotational direction with respect to the opening 62 of the low pressure chamber 61.

The positions of the suction port 81 and the opening 62 of the low pressure chamber 61 are determined by two dowel pins (not shown) provided in the pump cover 60 and two pin holes 84 (see FIG. 6) provided in the second side plate 80. Adapted.

Specifically, each dowel pin extends in the axial direction from the contact surface 60 a of the pump cover 60 that contacts the second side plate 80. The pin hole 84 penetrates the second side plate 80 in the axial direction. By inserting the dowel pin into the corresponding pin hole 84, the circumferential position of the pump cover 60 with respect to the second side plate 80 is adjusted.

In the present embodiment, the cam ring 40 has two pin holes 43 formed at positions corresponding to the pin holes 84 (see FIGS. 3, 7, and 8), and the first side plate 70 has the pin holes 43. 2 has two pin holes 76 formed at positions corresponding to (see FIG. 5). The pin hole 43 penetrates the cam ring 40 in the axial direction, and the pin hole 76 penetrates the first side plate 70 in the axial direction. That is, the pin holes 84, 43, 76 form through holes that pass from the second side plate 80 through the cam ring 40 to the first side plate 70. By inserting dowel pins into the pin holes 84, 43, 76, the positions of the pump cover 60, the second side plate 80, the cam ring 40, and the first side plate 70 are aligned.

The pin holes 84, 43, 76 are more than the conventional positions (the positions of the pin holes 84 such that the positions of the opening 62 of the low pressure chamber 61 and the suction port 81 coincide when the dowel pin is inserted into the pin hole 84). It is formed to be shifted forward in the rotational direction. Therefore, by inserting the dowel pins into the pin holes 84, 43, 76, the suction port 81 is disposed so as to be shifted forward in the rotational direction with respect to the opening 62 of the low pressure chamber 61.

Since the suction port 81 is positioned in front of the opening 62 of the low pressure chamber 61 in the rotational direction, the suction port 81 directs the flow of hydraulic oil guided from the low pressure chamber 61 to the pump chamber 41 in the rotational direction. That is, the flow velocity vector (inflow angle) is directed in the pump rotation direction. Therefore, when the hydraulic oil from the low pressure chamber 61 is sucked into the pump chamber 41, it flows into the front portion in the rotational direction of the pump chamber 41. Therefore, the suction characteristics of the vane pump 100 are improved, and the working oil is distributed to the front part in the rotational direction of the pump chamber 41. Since a sufficient amount of hydraulic oil is guided to the pump chamber 41, a decrease in pressure in the pump chamber 41 can be prevented, and the occurrence of cavitation can be prevented.

In the low-pressure chamber 61, a wall surface 63 is formed that crosses the rotation direction and guides the flow of hydraulic oil in the low-pressure chamber 61 toward the opening 62 in the axial direction. The wall surface 63 is inclined with respect to the axial direction so as to guide the hydraulic oil flowing out from the opening 62 forward in the rotational direction. Specifically, the wall surface 63 is inclined with respect to the axial direction so that the opening portion 62 is positioned on the front side in the rotational direction with respect to the end portion 63a of the wall surface 63 opposite to the opening portion 62.

Since the wall surface 63 of the low pressure chamber 61 directs the flow of hydraulic oil flowing out from the opening 62 to the front in the rotational direction, the hydraulic oil from the low pressure chamber 61 is rotated in the rotational direction of the pump chamber 41 when sucked into the pump chamber 41. It is difficult to stay in the rear part. Therefore, the suction characteristics of the vane pump 100 are improved, and the occurrence of cavitation can be prevented.

Furthermore, the suction port 81 is disposed so as to be shifted forward in the rotational direction with respect to the virtual extension surface of the wall surface 63 of the low pressure chamber 61. Specifically, the

openings

83 a and 83 b of the suction port 81 are located on the front side in the rotational direction with respect to the virtual extension surface of the wall surface 63 of the low pressure chamber 61.

Since the suction port 81 is positioned in front of the virtual extension surface of the wall surface 63 of the low pressure chamber 61 in the rotation direction, the flow of hydraulic oil in the low pressure chamber 61 is directed by the wall surface 63 of the low pressure chamber 61 and then the suction port 81 is hardly obstructed by the inner peripheral surface 81 (side surface of the recessed portion 82) 81a. Therefore, the hydraulic oil is more reliably filled in the rotation direction front portion of the pump chamber 41, and the suction characteristics of the vane pump 100 can be further improved.

In the present embodiment, the inner peripheral surface 81a of the suction port 81 is formed substantially parallel to the axial direction. However, as shown in FIG. 10, the inner peripheral surface 81a of the suction port 81 allows the flow of hydraulic oil forward in the rotational direction. It is desirable to be inclined with respect to the axial direction so that the Specifically, the inner peripheral surface 81a of the suction port 81 is inclined with respect to the axial direction so that the opening 83a of the suction port 81 is positioned on the front side in the rotational direction with respect to the opening 83b of the suction port 81. .

By inclining the inner peripheral surface 81a of the suction port 81 with respect to the axial direction, the flow of hydraulic fluid guided from the low pressure chamber 61 to the pump chamber 41 is directed forward in the rotational direction. Therefore, when the hydraulic oil from the low pressure chamber 61 is sucked into the pump chamber 41, the hydraulic oil is filled more in the front portion in the rotational direction of the pump chamber 41. Therefore, the suction characteristics of the vane pump 100 are improved, and the occurrence of cavitation can be prevented.

In the present embodiment, the

openings

83a and 83b of the suction port 81 are formed so that the width in the rotation direction is substantially equal to the opening 62 of the low-pressure chamber 61, but the

openings

83a and 83b of the suction port 81 are in the rotation direction. The width at may be larger than the opening 62.

The wall surface 63 of the low-pressure chamber 61 is not limited to a form that is inclined with respect to the axial direction, and the wall surface 63 may be formed to coincide with the axial direction.

Next, the operation of the vane pump 100 will be described with reference to FIGS.

When the power of the engine or the electric motor (not shown) is transmitted to the drive shaft 10, the rotor 20 rotates as the drive shaft 10 rotates. As the rotor 20 rotates, the vane 30 reciprocates with respect to the rotor 20, and the pump chamber 41 repeats expansion and contraction.

The hydraulic oil in the tank 2 is guided to the pump chamber 41 passing through the

expansion regions

42 a and 42 c through the low pressure chamber 61, the passage 54 and the suction port 74, and through the low pressure chamber 61 and the suction port 81.

The flow of hydraulic fluid guided to the pump chamber 41 through the suction port 81 is directed forward in the rotational direction by the suction port 81. Therefore, the suction characteristics of the vane pump 100 are improved, and the occurrence of cavitation can be prevented.

When the pump chamber 41 passes through the

contraction regions

42 b and 42 d, the hydraulic oil in the pump chamber 41 is discharged to the high-pressure chamber 53 and guided to the hydraulic device 1. Since the occurrence of cavitation is prevented, hydraulic oil having a higher pressure and a larger flow rate can be supplied to the hydraulic device 1.

Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

In the present embodiment, the vane pump 100 accommodates the rotor 20 that is rotationally driven, the plurality of vanes 30 that are provided in the rotor 20 so as to be capable of reciprocating in the radial direction of the rotor 20, and the rotor 20. A cam ring 40 having an inner circumferential cam surface 40a with which the tip portions 31 of the plurality of vanes 30 are in sliding contact with each other, and a pump chamber that is in contact with the end surface 40c of the cam ring 40 and partitioned by the plurality of vanes 30 between the rotor 20 and the cam ring 40 The second side plate 80 that divides 41 and the second side plate 80 are disposed between the cam ring 40 and the suction port 81 that leads the hydraulic oil to the pump chamber 41 and the cam ring 40. A pump cover 60; and a low pressure chamber 61 formed in the pump cover 60 and having an opening 62 communicating with the suction port 81. Suction port 81 is arranged offset forward in the rotational direction of the rotor 20 relative to the opening 62 of the low pressure chamber 61.

In this configuration, since the suction port 81 is arranged to be shifted forward in the rotational direction of the rotor 20 with respect to the opening 62 of the low pressure chamber 61, the hydraulic oil in the low pressure chamber 61 is transferred to the pump chamber 41 through the suction port 81. When sucked, it flows forward in the rotational direction of the rotor 20. Therefore, more hydraulic oil is filled in the front part of the pump chamber 41 in the rotation direction. Therefore, the suction characteristics of the vane pump 100 can be improved.

In the present embodiment, in the vane pump 100, the low pressure chamber 61 has a wall surface 63 that guides hydraulic oil to the suction port 81, and the wall surface 63 allows the hydraulic oil from the low pressure chamber 61 to move forward in the rotation direction of the rotor 20. Tilt to lead.

In this configuration, the wall surface 63 of the low pressure chamber 61 guides the hydraulic oil from the low pressure chamber 61 to the front in the rotational direction of the rotor 20, so that the hydraulic oil is drawn into the pump chamber 41 through the suction port 81. It flows more reliably forward in the direction of rotation. Therefore, the hydraulic oil is more reliably filled in the front portion in the rotational direction of the pump chamber 41, and the suction characteristics of the vane pump 100 can be further improved.

Further, in the present embodiment, the vane pump 100 is arranged such that the suction port 81 is shifted from the virtual extension surface of the wall surface 63 of the low pressure chamber 61 to the front side in the rotational direction of the rotor 20.

In this configuration, since the suction port 81 is arranged so as to be shifted from the virtual extension surface of the wall surface 63 of the low-pressure chamber 61 to the front side in the rotational direction of the rotor 20, the flow of hydraulic oil in the low-pressure chamber 61 After being oriented by the wall surface 63, it is difficult to be blocked by the inner peripheral surface 81 a of the suction port 81. Therefore, the hydraulic oil is reliably filled in the front portion of the pump chamber 41 in the rotation direction, and the suction characteristics of the vane pump 100 can be further improved.

Further, in the present embodiment, the vane pump 100 has an inner peripheral surface 81 a that is inclined so that the suction port 81 guides the hydraulic oil from the low pressure chamber 61 forward in the rotation direction of the rotor 20.

In this configuration, since the inner peripheral surface 81 a of the suction port 81 guides the hydraulic oil from the low pressure chamber 61 to the front in the rotational direction of the rotor 20, the hydraulic oil is sucked into the pump chamber 41 through the suction port 81. 20 flows more reliably forward in the rotational direction. Therefore, the hydraulic oil is reliably filled in the front portion of the pump chamber 41 in the rotation direction, and the suction characteristics of the vane pump 100 can be further improved.

The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

This application claims priority based on Japanese Patent Application No. 2015-215993 filed with the Japan Patent Office on November 2, 2015, the entire contents of which are incorporated herein by reference.

Claims

A vane pump,
A rotor that is driven to rotate;
A plurality of vanes provided in the rotor so as to be capable of reciprocating in the radial direction of the rotor;
A cam ring that houses the rotor and has an inner circumferential cam surface with which the tips of the plurality of vanes slide in contact with rotation of the rotor;
A side member that abuts against an end surface of the cam ring and defines a pump chamber partitioned by the plurality of vanes between the rotor and the cam ring;
A suction port provided in the side member and guiding the working fluid to the pump chamber;
A cover member disposed with the side member interposed between the cam ring and the cam ring;
A low pressure chamber formed in the cover member and having an opening communicating with the suction port;
The said suction port is a vane pump arrange | positioned and shifted | deviated to the rotation direction front side of the said rotor with respect to the said opening part of the said low pressure chamber.
The vane pump according to claim 1,
The low pressure chamber has a wall surface for guiding the working fluid to the suction port,
The vane pump, wherein the wall surface is inclined so as to guide the working fluid from the low pressure chamber forward in the rotational direction of the rotor.
The vane pump according to claim 2,
The said suction port is a vane pump arrange | positioned and shifted | deviated to the rotation direction front side of the said rotor rather than the virtual extension surface of the said wall surface of the said low pressure chamber.
The vane pump according to claim 1,
The said suction port is a vane pump which has an internal peripheral surface which inclines so that the working fluid from the said low pressure chamber may be guide | induced to the rotation direction front of the said rotor.