JP2024005951A - vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vane pump which stabilizes actuation of the pump.

SOLUTION: A vane pump 100 includes a body-side side plate 30 and a cover-side side plate 40. The body-side side plate 30 has a plurality of first back-pressure grooves 34 which are in communication with a back-pressure chamber 5 so as to be opened to a first sliding contact surface 30a with which each rotor 2 is brought into slide contact, and are provided at a gap to each other in a circumferential direction of the rotor 2, the cover-side side plate 40 has a plurality of second back-pressure grooves 44 which are in communication with the back pressure chamber so as to be opened to a second sliding contact surface 40a with which each rotor 2 is brought into slide contact and are provided by the same number with the plurality of first back-pressure grooves 34 and communication grooves 45 which are provided so as to be opened to the second sliding contact surface 40a and communicate with the plurality of second back-pressure grooves 44 which are adjacent to each other in the circumferential direction. Therein, an opening to the first sliding contact surface 30a of each of the plurality of first back-pressure grooves 34 has a larger opening area than an opening to each second sliding contact surface 40a of the plurality of second back-pressure groove 44.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a vane pump.

Patent Document 1 describes a rotor that is rotationally driven, a body-side side plate provided at one axial end of the rotor, a cover-side side plate provided at the other axial end of the rotor, and an opening on the outer periphery of the rotor. a plurality of slits formed in a radial shape with A vane pump is disclosed comprising: and a pump chamber defined between.

A back pressure chamber is defined within the slit by the base end of the vane. The body side side plate has a pair of back pressure ports that are formed to face each other across a through hole through which a drive shaft that rotationally drives the rotor is inserted, and a pair of back pressure ports that are approximately centered around the through hole. A pair of back pressure grooves are provided at positions shifted by 90 degrees, and the pair of back pressure ports and the pair of back pressure grooves each communicate with the back pressure chamber. The cover-side side plate has four arc-shaped back pressure grooves that are formed to communicate with adjacent back pressure chambers, and communication grooves that communicate with each of the adjacent back pressure grooves.

Japanese Patent Application Publication No. 2017-61904

In a vane pump as described in Patent Document 1, a pair of back pressure ports and a pair of back pressure grooves on a body side plate correspond to four back pressure grooves on a cover side plate. However, the structure corresponding to the communication groove of the cover-side side plate is not provided on the body-side side plate. Therefore, the rotor receives a greater load from the cover-side side plate than from the body-side side plate due to the pressure of the working fluid introduced into the communication groove. As a result, the rotor is pressed toward and comes into contact with the body-side side plate, and the frictional force generated between the rotor and the body-side side plate may affect the operation of the vane pump.

The present invention has been made in view of the above problems, and aims to stabilize the operation of a vane pump.

The present invention includes a rotor that is rotationally driven, a plurality of slits that open on the outer peripheral surface of the rotor, a plurality of vanes that are slidably housed in the slits, and tips of the vanes that slide as the rotor rotates. a cam ring having an inner peripheral cam surface in contact with the cam ring; a first side member provided in contact with one side surface of the cam ring; a second side member provided in contact with the other side surface of the cam ring; a rotor; a cam ring; a pump chamber defined by adjacent vanes, and a back pressure chamber defined by the proximal end of the vane in the slit, and each first side member has a first sliding surface on which the rotor slides. The second side member has a plurality of first back pressure grooves that open and communicate with the back pressure chamber and are spaced apart from each other in the circumferential direction of the rotor, and each of the second side members has a second sliding contact surface that is in sliding contact with the rotor. a plurality of second back pressure grooves that are open and communicate with the back pressure chamber and are provided in the same number as the plurality of first back pressure grooves; and a plurality of second back pressure grooves that are open and provided in the second sliding surface and that are adjacent to each other in the circumferential direction. a communication groove that communicates the back pressure grooves, and the opening to the first sliding surface of each of the plurality of first back pressure grooves is to the second sliding surface of each of the plurality of second back pressure grooves. The opening area is larger than that of the opening.

In this invention, the opening of each of the plurality of first back pressure grooves to the first sliding contact surface has a larger opening area than the opening of each of the plurality of second back pressure grooves to the second sliding contact surface. Therefore, even if the second side member has a communication groove in addition to the second back pressure groove, the load that the rotor receives from the first side member due to the pressure of the working fluid and the load that the rotor receives from the second side member are different. , are balanced. This prevents the rotor from being pressed toward and coming into contact with the first side member, thereby stabilizing the operation of the vane pump.

Further, the present invention is characterized in that the dimension of the first back pressure groove in the radial direction of the rotor at the opening to the first sliding surface is larger than the opening of the second back pressure groove to the second sliding surface. do.

Further, in the present invention, the plurality of first back pressure grooves include a discharge side first back pressure groove provided in a discharge region where the volume of the pump chamber contracts, and the plurality of second back pressure grooves include a discharge side first back pressure groove provided in a discharge region where the volume of the pump chamber contracts. A discharge side second back pressure groove provided in the region is included, the discharge side first back pressure groove and the discharge side second back pressure groove are provided so as to overlap each other in the axial direction of the rotor, and the first side member is , having a first through hole through which a drive shaft for rotationally driving the rotor is inserted, and a first discharge port provided such that the discharge side first back pressure groove is located between the first through hole, The second side member has a second through hole through which the drive shaft is inserted, and a second discharge port provided such that the discharge side second back pressure groove is located between the second through hole, The second side member has an inner dimension that is a radial dimension between the discharge side second back pressure groove and the second through hole, and a radial dimension between the discharge side second back pressure groove and the second discharge port. and the radial dimension between the first through hole and the first through hole if one of the grooves is larger than the other and the inner dimension is larger than the outer dimension. is smaller than the inner dimension, and if the outer dimension is larger than the inner dimension, the radial dimension between the first discharge port and the first discharge port is smaller than the outer dimension. do.

In these inventions, the first back pressure groove is provided so as to be wider than the second back pressure groove so that the larger one of the inner dimension and the outer dimension is smaller. Therefore, even if the opening area of the first back pressure groove is increased, the radial dimension between the first back pressure groove and the first through hole, which is the area where the rotor slides, and the first back pressure groove and the first A large radial dimension between the discharge port and the discharge port can be ensured. This prevents working fluid from leaking from the sliding surface between the first back pressure groove and the through hole and the rotor, and from the sliding surface between the first back pressure groove and the discharge port and the rotor. be done.

Further, the present invention provides that the total opening area of the plurality of first back pressure grooves is the same as the total opening area of the plurality of second back pressure grooves and the communication groove. Features.

In this invention, the load that the rotor receives from the first side member due to the pressure of the working fluid and the load that the rotor receives from the second side member can be balanced.

Further, the present invention provides a pump body having an accommodation recess for accommodating the rotor, a cam ring, a first side member, and a second side member, a pump cover that covers the accommodation recess and is fixed to the pump body, and a bottom side of the accommodation recess. The first side member further includes a high pressure chamber provided in the pump body and defined by the pump body and the first side member, and in which a high pressure working fluid discharged from the pump chamber is stored, and the first side member is defined by the rotor and the high pressure chamber. The plurality of first back pressure grooves provided between the plurality of first back pressure grooves are characterized in that the total opening area of the respective opening areas is larger than the total opening area of the plurality of second back pressure grooves and the communication groove. shall be.

In this invention, the first side member receives a load from the bottom side of the housing recess of the pump body toward the rotor due to the pressure of the working fluid in the high-pressure chamber, and bends toward the rotor. Therefore, the distance between the rotor and the first side member becomes smaller. However, by making the total opening area of the plurality of first back pressure chambers larger than the total opening area of the plurality of second back pressure chambers and the communication groove, the rotor can be moved from the first side member side due to the pressure of the working fluid. The load received is larger than the load received from the second side member side. As a result, the rotor is in a position close to the second side member, so even in a vane pump where the first side member is bent toward the rotor, the rotor will come into contact with the first side member and the second side member. This will be prevented.

Further, the present invention is characterized in that the second side member further includes a suction port that guides the working fluid into the pump chamber, and the communication groove communicates with the suction port.

In this invention, the pressure of the working fluid in the communication groove is reduced by communicating the communication groove with the suction port. Therefore, the load that the rotor receives from the working fluid guided to the communication groove is reduced, and the difference between the load that the rotor receives from the first side member and the load that the rotor receives from the second side member due to the pressure of the working fluid can be reduced. can. This prevents the rotor from coming into contact with the first side member.

According to the present invention, the operation of the vane pump is stabilized.

FIG. 1 is a sectional view of a vane pump according to an embodiment of the present invention. It is a front view of a rotor, a vane, and a cam ring, and shows a state where a rotor, a vane, and a cam ring were assembled. FIG. 3 is a front view of the body-side side plate seen from the pump cover side. It is a front view of the cover side plate seen from the pump cover side. It is a front view of the cover side plate seen from the rotor side. FIG. 7 is a front view of a cover-side side plate according to a modification of the embodiment of the present invention, viewed from the rotor side.

Hereinafter, a vane pump according to an embodiment of the present invention will be described with reference to the drawings. A vane pump is used as a fluid pressure supply source for fluid pressure equipment (for example, a power steering device, a transmission, etc.) mounted on a vehicle. Although a vane pump using hydraulic oil as the working fluid will be described here, other fluids such as working water may be used as the working fluid.

As shown in FIGS. 1 and 2, the vane pump 100 includes a pump body 10 having a housing recess 10A, a pump cover 20 that covers the housing recess 10A and is fixed to the pump body 10, and a bearing mounted on the pump body 10 and the pump cover 20. A drive shaft 1 rotatably supported via 11 and 12, a rotor 2 connected to the drive shaft 1 and rotationally driven, a plurality of slits 2s opening on the outer peripheral surface of the rotor 2, and a slit in the rotor 2. The rotor 2s includes a plurality of vanes 3 that are slidably housed in the rotor 2s, and a cam ring 4 having an inner circumferential cam surface 4a with which the tips 3a of the vanes 3 slide in contact as the rotor 2 rotates. Cam ring 4 accommodates rotor 2 and vane 3.

The vane pump 100 is driven by a drive device (not shown) such as an engine, and a rotor 2 connected to a drive shaft 1 is driven to rotate counterclockwise as shown by an arrow in FIG. to occur.

In the following, the direction along the rotation axis of the rotor 2 will be referred to as the "axial direction", and the radial direction centered on the rotation axis of the rotor 2 will be referred to as the "radial direction", and the direction in which the rotor 2 rotates when the vane pump 100 is operated is referred to as the "radial direction". It is called "rotation direction."

As shown in FIG. 1, the vane pump 100 includes a body-side side plate 30 as a first side member, which is provided at one axial end of the rotor 2 and in contact with one side surface of the rotor 2 and the cam ring 4; It further includes a cover-side side plate 40 as a second side member provided on the other axial end side of the rotor 2 and in contact with the other side surfaces of the rotor 2 and the cam ring 4.

The body-side side plate 30 is provided between the bottom surface of the housing recess 10A and the rotor 2. One axial end surface of the rotor 2 is in sliding contact with the body-side side plate 30, and one axial end surface of the cam ring 4 is in contact with the body side side plate 30. The cover-side side plate 40 is provided between the rotor 2 and the pump cover 20. The other axial end surface of the rotor 2 is in sliding contact with the cover-side side plate 40, and the other axial end surface of the cam ring 4 is in contact with the cover side plate 40.

In this way, the body-side side plate 30 and the cover-side side plate 40 are arranged to face both side surfaces of the rotor 2 and the cam ring 4. That is, the body-side side plate 30 and the cover-side side plate 40 are arranged to sandwich the rotor 2 and the cam ring 4 in the axial direction.

The body-side side plate 30, the rotor 2, the cam ring 4, and the cover-side side plate 40 are accommodated in the accommodation recess 10A of the pump body 10. In this state, the pump cover 20 is attached to the pump body 10, thereby sealing the housing recess 10A.

As shown in FIG. 2, a plurality of slits 2s are radially formed in the rotor 2. The slit 2s opens on the outer periphery of the rotor 2.

The vane 3 is formed into a rectangular flat plate shape. The vane 3 is slidably inserted into the slit 2s and has a distal end 3a that is an end protruding from the slit 2s, and a proximal end 3b that is an end opposite to the distal end 3a. . A back pressure chamber 5 is defined by the base end portion 3b of the vane 3 within the slit 2s. The back pressure chamber 5 communicates with a high pressure chamber 14 as will be described later, and hydraulic oil is introduced into the back pressure chamber 5 from the high pressure chamber 14 . The vane 3 is pushed in the direction of protruding from the slit 2s by the pressure of the hydraulic oil guided to the back pressure chamber 5.

The cam ring 4 is an annular member having an inner circumferential cam surface 4a that is a substantially oval inner circumferential surface, and a pin hole 4b through which the positioning pin 8 is inserted. The inner circumferential cam surface 4a is a surface on which the tip portions 3a of the plurality of vanes 3 come into sliding contact as the rotor 2 rotates.

When the rotor 2 rotates, centrifugal force is generated in the vanes 3. This centrifugal force pushes the vane 3 in the direction of protruding from the slit 2s. In other words, the vane 3 is pressed in the direction of protruding from the slit 2s (radially outward) by the fluid pressure in the back pressure chamber 5 pressing the base end 3b and the centrifugal force acting as the rotor 2 rotates. Ru. When the vane 3 is pressed outward in the radial direction, the tip end 3a of the vane 3 comes into sliding contact with the inner cam surface 4a of the cam ring 4. As a result, a pump chamber 6 is defined inside the cam ring 4 by the outer circumferential surface of the rotor 2, the inner circumferential cam surface 4a of the cam ring 4, and a pair of adjacent vanes 3.

The inner circumferential cam surface 4a is formed in a substantially elliptical shape. Therefore, as the rotor 2 rotates, the volume of the pump chamber 6 repeatedly expands and contracts. Hydraulic oil is sucked into an expansion area (suction area) where the pump chamber 6 expands, and hydraulic oil is discharged from a contraction area (discharge area) where the pump chamber 6 contracts.

As shown in FIG. 1, an annular high pressure chamber 14 is defined by the pump body 10 and the body-side side plate 30 on the bottom side of the housing recess 10A of the pump body 10. The high-pressure chamber 14 is provided between the bottom surface of the housing recess 10A and the body-side side plate 30, and stores high-pressure hydraulic oil discharged from the pump chamber 6. The high pressure chamber 14 is connected to a fluid pressure device 70 (for example, a power steering device, a transmission, etc.) outside the vane pump 100 via a discharge passage 62. The discharge passage 62 is, for example, a passage provided on the vane pump 100 side.

A low pressure chamber 21 is formed in the pump cover 20, and a detour passage 13 communicating with the low pressure chamber 21 is formed in the inner peripheral surface of the housing recess 10A. Two detour passages 13 are provided at opposing positions with the cam ring 4 in between. Low pressure chamber 21 is connected to tank 60 via suction passage 61.

As shown in FIGS. 1 and 2, the cam ring 4 is provided with notches 4c and 4d that penetrate from the outer circumferential surface to the inner circumferential cam surface 4a. The notch portion 4c opens on the side surface in contact with the body-side side plate 30, and the notch portion 4d opens on the side surface in contact with the cover-side side plate 40.

FIG. 3 is a front view of the body-side side plate 30 seen from the cam ring 4 side. As shown in FIG. 3, the body-side side plate 30 has a first sliding surface 30a on which the side surface of the vane 3 slides, and a first discharge port 31 formed to correspond to each of the discharge regions 50b and 50d. , a plate having a first through hole 32 through which the drive shaft 1 is inserted, a first suction port 33 formed to correspond to each of the suction regions 50a and 50c, and a pin hole 39 through which the positioning pin 8 is inserted. It is a shaped member.

The first discharge ports 31 are provided at two positions facing each other with the first through hole 32 in between. The first discharge port 31 is formed in an arc shape centered on the first through hole 32 . The first discharge port 31 penetrates the body-side side plate 30 and communicates with the high pressure chamber 14 formed in the pump body 10 . The first discharge port 31 guides hydraulic oil discharged from the pump chamber 6 to the high pressure chamber 14 . The hydraulic oil that has flowed into the high pressure chamber 14 is supplied to the fluid pressure device 70 outside the vane pump 100 through the discharge passage 62 (see FIG. 1).

The first suction ports 33 are provided at two positions facing each other with the first through hole 32 in between. The first suction port 33 is formed at a position corresponding to the detour passage 13 of the accommodation recess 10A. The first suction port 33 is formed in a concave shape that opens outward in the radial direction. The outer peripheral end of the first suction port 33 reaches the outer peripheral surface of the body-side side plate 30.

As shown in FIG. 1, when the body-side side plate 30 is assembled to the cam ring 4, the first suction port 33 of the body-side side plate 30 faces the notch 4c of the cam ring 4. The hydraulic oil in the detour passage 13 is guided to the pump chamber 6 through between the notch 4c and the first suction port 33. The first suction port 33 guides hydraulic oil from the low pressure chamber 21 to the pump chamber 6 .

As shown in FIG. 3, a groove-shaped notch 36 is formed in the first sliding surface 30a of the body-side side plate 30. The notch 36 is provided at the end of the first discharge port 31 on the communication start side where the pump chamber 6 starts communicating with the rotation of the rotor 2, and communicates with the first discharge port 31. The notch 36 is formed so that its opening area gradually increases in the direction of rotation of the rotor 2. By forming the notch 36, hydraulic oil is supplied to the pump chamber 6 through the notch 36 before the pump chamber 6 opens directly to the first discharge port 31. This increases the pressure in the pump chamber 6, thereby preventing rapid pressure fluctuations in the high pressure chamber 14.

The body-side side plate 30 has a plurality of first back pressure grooves 34 that are open to the first sliding surface 30a, communicate with the back pressure chamber 5, and are spaced apart from each other in the circumferential direction of the rotor 2. In this embodiment, one first back pressure groove 34 is provided in each of the suction regions 50a, 50c and the discharge regions 50b, 50d, and a total of four first back pressure grooves 34 are provided. The plurality of first back pressure grooves 34 are each provided in the same shape. The first back pressure grooves 34a, 34c provided in the suction regions 50a, 50c are provided so as to face each other across the first through hole 32, and the first back pressure grooves 34b, 34d provided in the discharge regions 50b, 50d are (Discharge side first back pressure grooves) are provided so as to face each other with the first through hole 32 in between. The first back pressure groove 34 is provided between the first through hole 32 and the first discharge port 31. Specifically, the first back pressure groove 34b provided in the discharge region 50b is provided between the first discharge port 31 and the first through hole 32 provided in the same discharge region 50b. The same applies to the first back pressure groove 34d provided in the discharge area 50d. In other words, the first discharge port 31 is provided such that the first back pressure grooves 34b, 34d provided in the discharge regions 50b, 50d are located between the first through hole 32. The openings to the first sliding surface 30a of each of the plurality of first back pressure grooves 34 are the same as the openings to the second sliding surface 40a of each of the plurality of second back pressure grooves 44, which will be described later, of the cover side side plate 40. The opening area is larger than that of the Details of the opening area of the first back pressure groove 34 will be described later.

The first back pressure groove 34 overlaps and communicates with the plurality of back pressure chambers 5 as the rotor 2 rotates. The first back pressure groove 34 is provided to penetrate the body side side plate 30 and communicates with the high pressure chamber 14 . Thereby, high-pressure hydraulic oil from the first discharge port 31 is guided to the back pressure chamber 5 through the high pressure chamber 14 and the first back pressure groove 34. The back pressure chamber 5 presses the vane 3 toward the inner circumferential cam surface 4a by the hydraulic oil guided through the first back pressure groove 34, and causes the vane 3 to come into sliding contact with the inner circumferential cam surface 4a.

FIG. 4 is a front view of the cover-side side plate 40 seen from the pump cover 20 side. As shown in FIG. 4, the cover-side side plate 40 has a second through hole 42 through which the drive shaft 1 is inserted, a second suction port 43 as a suction port that guides hydraulic oil to the pump chamber 6, and a positioning pin 8. It is a plate-like member having a pin hole 49 to be inserted therethrough. The cover-side side plate 40 is positioned with respect to the cam ring 4 and the body-side side plate 30 by the positioning pin 8.

The second suction ports 43 are provided in each of the suction regions 50a and 50c, and are provided in two positions facing each other with the second through hole 42 in between. The second suction port 43 is formed at a position corresponding to the detour passage 13 of the accommodation recess 10A. The second suction port 43 is provided to open radially outward. As shown in FIG. 1, when the cover side plate 40 is assembled to the cam ring 4, the second suction port 43 of the cover side plate 40 faces the notch 4d of the cam ring 4. The hydraulic oil in the detour passage 13 and the low pressure chamber 21 is guided to the pump chamber 6 through the second suction port 43 and the notch 4d.

FIG. 5 is a front view of the cover side plate 40 seen from the rotor 2 side. As shown in FIG. 5, the cover-side side plate 40 has a second sliding surface 40a on which the side surface of the vane 3 slides, and a second discharge port 41 formed to correspond to each of the discharge regions 50b and 50d. , a plurality of second back pressure grooves 44 which are opened in the second sliding contact surface 40a and communicated with the back pressure chamber 5, and which are provided in the same number as the plurality of first back pressure grooves 34, and open in the second sliding contact surface 40a. It has a communication groove 45 that is provided and communicates a plurality of second back pressure grooves 44 adjacent in the circumferential direction. The second discharge port 41, the second back pressure groove 44, the communication groove 45, and the notch 46 provided in the second discharge port 41, which will be described later, do not penetrate the cover side plate 40 in the axial direction.

The second discharge ports 41 are provided at two positions facing each other with the second through hole 42 in between. Further, a notch 46 is provided at the end of the second discharge port 41 on the communication start side where the pump chamber 6 starts communicating with the rotation of the rotor 2 . The second discharge port 41 and the notch 46 are provided corresponding to the first discharge port 31 and the notch 36. Specifically, the second discharge ports 41 are provided so as to overlap with the first discharge ports 31 in the axial direction, and are provided in the same size and in the same number as the first discharge ports 31. The notches 46 are provided so as to overlap with the notches 36 in the axial direction, and are provided in the same size and number as the notches 36. The second discharge port 41 differs from the first discharge port 31 in that it does not directly communicate with the high pressure chamber 14 .

Since the second discharge port 41 communicates with the first discharge port 31 through the pump chamber 6, the same pressure as that of the first discharge port 31 acts on the second discharge port 41. Since the second discharge port 41 is provided to face the first discharge port 31 with the vane 3 in between, the force acting on the vane 3 due to the pressure inside the first discharge port 31 is due to the pressure in the second discharge port 41. canceled out. This prevents the vane 3 from being pressed against the cover-side side plate 40 due to the pressure inside the first discharge port 31.

The second back pressure grooves 44 are provided at intervals in the circumferential direction of the rotor 2, and one is provided in each of the suction regions 50a, 50c and the discharge regions 50b, 50d. The plurality of second back pressure grooves 44 are each provided in the same shape. The second back pressure groove 44 is provided corresponding to the first back pressure groove 34. Specifically, the second back pressure grooves 44 are provided so as to overlap with the first back pressure grooves 34 in the axial direction, and are provided in the same number as the first back pressure grooves 34. The second back pressure groove 44 is provided between the second through hole 42 and the second discharge port 41. Specifically, the second back pressure groove 44b (discharge side second back pressure groove) provided in the discharge area 50b is between the second discharge port 41 and the second through hole 42 provided in the same discharge area 50b. provided. The same applies to the second back pressure groove 44d provided in the discharge area 50d. In other words, the second discharge port 41 is provided so that the second back pressure grooves 44b, 44d (discharge side first back pressure grooves) provided in the discharge areas 50b, 50d are located between the second through hole 42. It will be done. Further, in this embodiment, the second back pressure grooves 44b, 44d provided in the discharge areas 50b, 50d are located outside, which is the radial dimension between the second back pressure grooves 44b, 44d and the second discharge port 41. The dimension B is set larger than the inner dimension A, which is the radial dimension between the second back pressure grooves 44b, 44d and the second through hole 42. The second back pressure grooves 44a, 44c provided in the suction areas 50a, 50c are also provided in the same shape.

A plurality of communication grooves 45 are provided in an arc shape, and include a second back pressure groove 44a and a second back pressure groove 44b, a second back pressure groove 44b and a second back pressure groove 44c, and a second back pressure groove 44c and a second back pressure groove. The pressure groove 44d and the second back pressure groove 44d communicate with the second back pressure groove 44a, respectively. The communication groove 45 allows all of the plurality of second back pressure grooves 44 to communicate with each other. The second back pressure groove 44 and the communication groove 45 form an annular groove that opens toward the rotor 2 in the cover side plate 40 . The communication groove 45 is provided so that the radial dimension of the opening of the second sliding contact surface 40a is smaller than each of the plurality of second back pressure grooves 44. The second back pressure groove 44 and the communication groove 45 communicate with the back pressure chamber 5 and do not communicate with the low pressure chamber 21 .

The hydraulic oil supplied to the back pressure chambers 5 from the first back pressure groove 34 of the body side side plate 30 is supplied to all the back pressure chambers 5 through the second back pressure groove 44 and the communication groove 45 of the cover side side plate 40. Supplied. Therefore, all the back pressure chambers 5 are supplied with the hydraulic oil discharged from the pump chamber 6. Therefore, all the vanes 3 of the vane pump 100 rotate while their tip portions 3a are in sliding contact with the inner circumferential cam surface 4a of the cam ring 4.

In this way, in the body side side plate 30 and the cover side side plate 40, the first discharge port 31 and the second discharge port 41, the first suction port 33 and the second suction port 43, and the first back pressure groove 34 and the second Two back pressure grooves 44 are provided at positions that correspond to each other and overlap in the axial direction.

Furthermore, in the body-side side plate 30, the first back pressure groove 34 opens to the first sliding surface 30a, and high pressure hydraulic oil from the first discharge port 31 is guided through the high pressure chamber 14. Therefore, the rotor 2 receives a load from the body-side side plate 30 due to the pressure of the hydraulic oil guided to the first back pressure groove 34. Furthermore, in the cover-side side plate 40, the second back pressure groove 44 and the communication groove 45 are open to the second sliding surface 40a, and the high-pressure hydraulic oil from the high pressure chamber 14 is directed to the first back of the body side side plate 30. It is guided through the pressure groove 34 and the back pressure chamber 5. Therefore, the rotor 2 receives a load from the cover side plate 40 side due to the pressure of the hydraulic oil guided to the second back pressure groove 44 and the communication groove 45.

Here, in the vane pump 100, as described above, the first back pressure groove 34 of the body side side plate 30 and the second back pressure groove 44 of the cover side plate 40 correspond to each other. However, the structure corresponding to the communication groove 45 of the cover-side side plate 40 is not provided on the body-side side plate 30. Therefore, if the opening areas of the first back pressure groove 34 and the second back pressure groove 44 toward the rotor 2 are the same, the rotor 2 will be moved toward the body side by an amount equal to the pressure of the hydraulic fluid guided to the communication groove 45. A larger load is received from the cover side side plate 40 side than from the side plate 30 side. As a result, the rotor 2 is pressed toward and comes into contact with the body-side side plate 30, and the frictional force generated between the rotor 2 and the body-side side plate 30 may affect the operation of the vane pump 100. Further, since the distance between the rotor 2 and the cover-side side plate 40 becomes large, there is a risk that hydraulic oil may leak from between the two. Therefore, in the vane pump 100 of this embodiment, the first back pressure groove 34 is provided with a larger opening area toward the rotor 2 than each of the plurality of second back pressure grooves 44.

Next, the opening area of the first back pressure groove 34 will be explained.

The dimension of the first back pressure groove 34 in the radial direction of the rotor 2 at the opening to the first sliding surface 30a is larger than the opening of the second back pressure groove 44 to the second sliding surface 40a. Specifically, when the inner dimension A of the cover-side side plate 40 is larger than the outer dimension B, the dimension between the first back pressure groove 34 and the first through hole 32 is smaller than the inner dimension A. When the outer dimension B of the cover side plate 40 is larger than the inner dimension A, the dimension between the cover side plate 40 and the first discharge port 31 is smaller than the outer dimension B. In other words, the first back pressure groove 34 has a shape in which the second back pressure groove 44 is expanded toward the larger of the inner dimension A and the outer dimension B. In the vane pump 100 of this embodiment, the outer dimension B of the cover-side side plate 40 is larger than the inner dimension A, so the dimension between the first back pressure groove 34 and the first discharge port 31 is larger than the outer dimension B. It is set to become smaller. In other words, the first back pressure groove 34 has a shape such that the second back pressure groove 44 widens toward the second discharge port 41 . The shape of the first back pressure groove 34 on the first through hole 32 side (in other words, the shape of the inner peripheral surface of the first back pressure groove 34) is the shape of the second back pressure groove 44 on the second through hole 42 side ( In other words, it is the same as the shape of the inner circumferential surface of the second back pressure groove 44). The inner circumferential surface of the first back pressure groove 34 overlaps the inner circumferential surface of the second back pressure groove 44 in the axial direction. Note that when the inner dimension A of the cover-side side plate 40 is larger than the outer dimension B, the first back pressure groove 34 has a shape in which the second back pressure groove 44 widens toward the second through hole 42. The outer peripheral surface of the first back pressure groove 34 overlaps the outer peripheral surface of the second back pressure groove 44 in the axial direction.

Further, the plurality of first back pressure grooves 34 have a total opening area that is the sum of the opening areas of the respective openings of the first sliding surface 30a, which is the sum of the plurality of second back pressure grooves 44 and the communication groove 45. It is the same as the opening area. In other words, the first back pressure groove 34 is provided with a larger opening area than the second back pressure groove 44 by the opening area of the communication groove 45 .

In this manner, in the vane pump 100, the openings of the plurality of first back pressure grooves 34 to the first sliding surface 30a are larger than the openings of the plurality of second back pressure grooves 44 to the second sliding surface 40a. Large opening area. Therefore, even if the cover-side side plate 40 has the communication groove 45 in addition to the second back pressure groove 44, the load that the rotor 2 receives from the body-side side plate 30 due to the pressure of the hydraulic oil and the cover-side side plate The load received from the 40 side is balanced. In particular, in the vane pump 100 of this embodiment, the load that the rotor 2 receives from the body-side side plate 30 side due to the pressure of the hydraulic oil and the load that the rotor 2 receives from the cover-side side plate 40 side can be balanced. Thereby, the rotor 2 is prevented from being pressed toward the body-side side plate 30 and comes into contact with it, and the operation of the vane pump 100 is stabilized.

Further, the first back pressure groove 34 is provided so as to be wider than the second back pressure groove 44 so that the larger one of the inner dimension A and the outer dimension B is smaller. Therefore, the first back pressure groove 34 can be made larger than the second back pressure groove 44 without reducing the smaller of the inner dimension A and the outer dimension B. Therefore, the radial dimension between the first back pressure groove 34 and the first through hole 32, which is the area in which the rotor 2 slides, and the radial dimension between the first back pressure groove 34 and the first discharge port 31. Larger dimensions can be ensured. Thereby, the sliding contact surface between the first back pressure groove 34 and the first through hole 32 and the rotor 2, and the sliding contact between the first back pressure groove 34 and the first discharge port 31 and the rotor 2. Hydraulic oil is prevented from leaking from the surface. Therefore, the operation of vane pump 100 becomes more stable.

Next, the operation of vane pump 100 will be explained.

When the drive shaft 1 is rotationally driven by the power of a drive device (not shown) such as an engine, the rotor 2 rotates in the direction shown by the arrow in FIG. As the rotor 2 rotates, the pump chamber 6 located in the suction areas 50a and 50c expands. As a result, the hydraulic oil in the tank 60 is sucked into the pump chamber 6 through the suction passage 61, the low pressure chamber 21, the first suction port 33, and the second suction port 43 of the cover side plate 40, as shown in FIG. . Furthermore, as the rotor 2 rotates, the pump chambers 6 located in the discharge areas 50b and 50d contract. Thereby, the hydraulic oil in the pump chamber 6 is discharged to the high pressure chamber 14 through the first discharge port 31 (see FIG. 2). The hydraulic fluid discharged into the high pressure chamber 14 is supplied to an external fluid pressure device 70 through a discharge passage 62. In the vane pump 100 of this embodiment, each pump chamber 6 repeats suction and discharge of hydraulic oil twice while the rotor 2 rotates once.

A part of the hydraulic fluid discharged into the high pressure chamber 14 is supplied to the back pressure chamber 5 through the first back pressure groove 34, and presses the base end portion 3b of the vane 3 toward the inner circumferential cam surface 4a. Further, the hydraulic oil supplied to the back pressure chambers 5 is supplied to all the back pressure chambers 5 through the second back pressure groove 44 and the communication groove 45 of the cover side plate 40. Therefore, the vane 3 is pressed in the direction of protruding from the slit 2s by the fluid pressure in the back pressure chamber 5 pressing the base end 3b and the centrifugal force acting as the rotor 2 rotates. As a result, the tip portion 3a of the vane 3 rotates while slidingly contacting the inner circumferential cam surface 4a of the cam ring 4, so that the hydraulic oil in the pump chamber 6 is transferred between the tip portion 3a of the vane 3 and the inner circumferential cam surface 4a of the cam ring 4. It is discharged from the first discharge port 31 without leaking between the two.

According to the present embodiment described above, the following effects are achieved.

In the vane pump 100, the opening of the plurality of first back pressure grooves 34 to the first sliding surface 30a has a larger opening area than the opening of each of the plurality of second back pressure grooves 44 to the second sliding surface 40a. . Therefore, even if the cover-side side plate 40 has the communication groove 45 in addition to the second back pressure groove 44, the load that the rotor 2 receives from the body-side side plate 30 due to the pressure of the hydraulic oil and the cover-side side plate The load received from the 40 side is balanced. In particular, in the vane pump 100, the load that the rotor 2 receives from the body-side side plate 30 side due to the pressure of the hydraulic oil and the load that the rotor 2 receives from the cover-side side plate 40 side can be balanced. Thereby, the rotor 2 is prevented from being pressed toward the body-side side plate 30 and comes into contact with it, and the operation of the vane pump 100 is stabilized.

In the vane pump 100, the first back pressure groove 34 is provided so as to widen with respect to the second back pressure groove 44 so that the larger one of the inner dimension A and the outer dimension B is smaller. Therefore, even if the opening area of the first back pressure groove 34 is increased, the radial dimension between the first back pressure groove 34 and the first through hole 32, which is the area where the rotor 2 slides, and the first back pressure A large radial dimension between the groove 34 and the first discharge port 31 can be ensured. Thereby, the sliding contact surface between the first back pressure groove 34 and the first through hole 32 and the rotor 2, and the sliding contact between the first back pressure groove 34 and the first discharge port 31 and the rotor 2. Hydraulic oil is prevented from leaking from the surface. Therefore, the operation of vane pump 100 becomes more stable.

Next, a modification of this embodiment will be described. The following modified examples are also within the scope of the present invention, and it is also possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, or to combine the configurations described in the following different modified examples. It is.

<Modification 1>
In the embodiment described above, the total opening area of the openings to the first sliding surface 30a of each of the plurality of first back pressure grooves 34 is the total opening area of the plurality of second back pressure grooves 44 and the communication groove 45. is the same as However, if the first back pressure groove 34 has a configuration in which the opening area of the first sliding surface 30a is larger than each of the plurality of second back pressure grooves 44, the total opening area of the first back pressure groove 34 is larger than that of each of the plurality of second back pressure grooves 44. 44 and the communication groove 45 may not have the same total opening area. In other words, the load that the rotor 2 receives from the body-side side plate 30 side due to the pressure of the hydraulic oil and the load that the rotor 2 receives from the cover-side side plate 40 side do not need to be completely balanced. Even with this configuration, the pressure of the hydraulic oil guided to the first back pressure groove 34 can buffer the load applied to the rotor 2 by the hydraulic oil guided to the second back pressure groove 44 and the communication groove 45.

Further, in the embodiment described above, the body side side plate 30 is provided between the rotor 2 and the high pressure chamber 14. Therefore, the body-side side plate 30 receives a load from the bottom side of the accommodation recess 10A of the pump body 10 toward the rotor 2 side due to the pressure of the hydraulic oil in the high-pressure chamber 14, and it is conceivable that the body-side side plate 30 bends toward the rotor 2 side. . When the body-side side plate 30 bends toward the rotor 2, the distance (axial distance) between the rotor 2 and the body-side side plate 30 becomes smaller. On the other hand, when the total opening area of the plurality of first back pressure grooves 34 is made larger than the total opening area of the plurality of second back pressure grooves 44 and the communication groove 45, the rotor 2 is moved to the body by the pressure of the hydraulic oil. The load received from the side side plate 30 side becomes larger than the load received from the cover side side plate 40 side. Thereby, the rotor 2 is in a position closer to the cover side plate 40, and the distance between the rotor 2 and the body side plate 30 can be secured. Therefore, even in the vane pump 100 in which the body-side side plate 30 is bent toward the rotor 2, the rotor 2 is prevented from coming into contact with the body-side side plate 30 and the cover-side side plate 40.

<Modification 2>
In the embodiment described above, the plurality of first back pressure grooves 34 are provided with a larger opening area to the first sliding surface 30a than each of the plurality of second back pressure grooves 44, so that the rotor 2 is The load received from the body side side plate 30 side and the load received from the cover side side plate 40 side are balanced. In addition, as shown in FIG. 6, the communication groove 45 may be configured to communicate with the second suction port 43. The second back pressure groove 44 is provided with a groove 48 that communicates with the second suction port 43 , and the communication groove 45 communicates with the second suction port 43 via the groove 48 and the second back pressure groove 44 . The groove 48 is provided so as to be offset from the radial direction of the rotor 2 so as not to obstruct the sliding movement of the vane 3 within the slit 2s. By communicating the groove 48 with the second suction port 43, the pressure of the hydraulic oil in the communication groove 45 is reduced. Therefore, the load that the rotor 2 receives from the hydraulic oil guided to the communication groove 45 becomes smaller, and the difference between the load that the rotor 2 receives from the body-side side plate 30 side and the load that the rotor 2 receives from the cover-side side plate 40 side due to the pressure of the hydraulic oil is reduced. can be made smaller. This prevents the rotor 2 from coming into contact with the body-side side plate 30.

Note that the groove 48 may be provided in the communication groove 45 to communicate the communication groove 45 and the second suction port 43. Moreover, in this modification, the difference between the load that the rotor 2 receives from the body side side plate 30 side and the load that the rotor 2 receives from the cover side side plate 40 side due to the pressure of the hydraulic oil can be reduced, so the first back pressure groove 34 may be provided so that the opening area facing the rotor 2 is the same as each of the plurality of second back pressure grooves 44 . Further, the second back pressure groove 44 and the communication groove 45 may have the same width and may be provided as one annular groove.

Hereinafter, the configuration, operation, and effects of the embodiments of the present invention will be collectively described.

The vane pump 100 includes a rotor 2 that is rotationally driven, a plurality of slits 2s that open on the outer peripheral surface of the rotor 2, a plurality of vanes 3 that are slidably housed in the slits 2s, and a rotor 2 that is driven to rotate. A cam ring 4 having an inner circumferential cam surface 4a with which the tip end 3a of the vane 3 slides, a body side side plate 30 as a first side member provided in contact with one side of the cam ring 4, and a side plate 30 on the other side of the cam ring 4. A cover-side side plate 40 as a second side member provided in contact with the side surface, a pump chamber 6 defined by the rotor 2, the cam ring 4, and a pair of adjacent vanes 3, and a base of the vane 3 in the slit 2s. A back pressure chamber 5 defined by the end portion 3b, and each of the body side side plates 30 opens at a first sliding surface 30a on which the rotor 2 slides and communicates with the back pressure chamber 5. The cover-side side plate 40 has a plurality of first back pressure grooves 34 provided at intervals in the circumferential direction, and the cover side plate 40 is opened to a second sliding surface 40a on which the rotor 2 slides, and the back pressure chamber 5 is opened. a plurality of second back pressure grooves 44 that are in communication with each other and are provided in the same number as the plurality of first back pressure grooves 34; and a plurality of second back pressure grooves that are open to the second sliding surface 40a and that are adjacent to each other in the circumferential direction. 44, and an opening to each of the first sliding surfaces 30a of each of the plurality of first back pressure grooves 34 is a communication groove 45 that communicates with each other of the plurality of second back pressure grooves 44. The opening area is larger than the opening to the surface 40a.

In this configuration, the openings of the plurality of first back pressure grooves 34 to the first sliding surface 30a have a larger opening area than the openings of the plurality of second back pressure grooves 44 to the second sliding surface 40a. . Therefore, even if the cover-side side plate 40 has the communication groove 45 in addition to the second back pressure groove 44, the load that the rotor 2 receives from the body-side side plate 30 due to the pressure of the working fluid and the cover-side side plate The load received from the 40 side is balanced. Thereby, the rotor 2 is prevented from being pressed toward the body-side side plate 30 and comes into contact with it, and the operation of the vane pump 100 is stabilized.

Furthermore, in the vane pump 100, the radial dimension of the rotor 2 at the opening to the first sliding surface 30a is larger than the opening of the second back pressure groove 44 to the second sliding surface 40a.

In the vane pump 100, the plurality of first back pressure grooves 34 include discharge side first back pressure grooves 34b, 34d provided in the discharge areas 50b, 50d where the volume of the pump chamber 6 contracts, The two back pressure grooves 44 include discharge side second back pressure grooves 44b and 44d provided in the discharge areas 50b and 50d, and include discharge side first back pressure grooves 34b and 34d and discharge side second back pressure grooves 44b, 44d are provided so as to overlap each other in the axial direction of the rotor 2, and the body side side plate 30 has a first through hole 32 through which the drive shaft 1 that rotationally drives the rotor 2 is inserted, and a first discharge side back pressure. The cover-side side plate 40 has a first discharge port 31 provided so that the grooves 34b and 34d are located between the first through-hole 32 and the second through-hole 42 through which the drive shaft 1 is inserted. and a second discharge port 41 provided such that the discharge side second back pressure grooves 44b, 44d are located between the second through hole 42, and the cover side side plate 40 has The inner dimension A is the radial dimension between the back pressure grooves 44b, 44d and the second through hole 42, and the radial dimension A is the radial dimension between the discharge side second back pressure grooves 44b, 44d and the second discharge port 41. One of the outer dimensions B and B is larger than the other, and when the inner dimension A is larger than the outer dimension B, the discharge side first back pressure grooves 34b and 34d are connected to the first through hole 32. If the radial dimension between the two is smaller than the inner dimension A, and the outer dimension B is larger than the inner dimension A, the radial dimension between the first discharge port 31 and the first discharge port 31 is smaller than the outer dimension B. It is set so that it is also small.

In these configurations, the first back pressure groove 34 is provided so as to widen toward the larger of the inner dimension A and the outer dimension B with respect to the second back pressure groove 44 . Therefore, even if the opening area of the first back pressure groove 34 is increased, the radial dimension between the first back pressure groove 34 and the first through hole 32 and the first back pressure groove 34 and the first discharge port 31 It is possible to secure a large radial dimension between the two. Thereby, the sliding contact surface between the first back pressure groove 34 and the first through hole 32 and the rotor 2, and the sliding contact between the first back pressure groove 34 and the first discharge port 31 and the rotor 2. Working fluid is prevented from leaking from the surface.

Furthermore, in the vane pump 100, the total opening area of the plurality of first back pressure grooves 34 is the same as the total opening area of the plurality of second back pressure grooves 44 and the communication groove 45. be.

With this configuration, the load that the rotor 2 receives from the body-side side plate 30 side due to the pressure of the working fluid and the load that the rotor 2 receives from the cover-side side plate 40 side can be balanced.

Further, the vane pump 100 includes a pump body 10 having an accommodation recess 10A that accommodates the rotor 2, a cam ring 4, a body-side side plate 30, and a cover-side side plate 40, and a pump that covers the accommodation recess 10A and is fixed to the pump body 10. The high pressure chamber 14 is provided on the bottom side of the housing recess 10A, is defined by the pump body 10 and the body side side plate 30, and stores the high pressure working fluid discharged from the pump chamber 6. Furthermore, the body side side plate 30 is provided between the rotor 2 and the high pressure chamber 14, and the first back pressure groove 34 has a total opening area that is equal to or larger than the plurality of second back pressure grooves 44 and the communication groove 45. , is larger than the total aperture area of .

In this configuration, the body-side side plate 30 receives a load from the bottom side of the accommodation recess 10A of the pump body 10 toward the rotor 2 due to the pressure of the working fluid in the high-pressure chamber 14, and is bent toward the rotor 2. Therefore, the distance between the rotor 2 and the body-side side plate 30 becomes smaller. However, by making the total opening area of the plurality of first back pressure grooves 34 larger than the total opening area of the plurality of second back pressure grooves 44 and the communication groove 45, the rotor 2 is moved toward the body side by the pressure of the working fluid. The load received from the side plate 30 side becomes larger than the load received from the cover side side plate 40 side. As a result, the rotor 2 is in a position close to the cover-side side plate 40, so even if the vane pump 100 is such that the body-side side plate 30 is bent toward the rotor 2, the rotor 2 is close to the body-side side plate 30 and the cover side. Contact with the side plate 40 is prevented.

In the vane pump 100, the cover side plate 40 further includes a suction port 43 that guides the working fluid into the pump chamber 6, and the communication groove 45 communicates with the suction port 43.

In this configuration, the communication groove 45 communicates with the suction port 43, thereby reducing the pressure of the working fluid within the communication groove 45. Therefore, the load that the rotor 2 receives from the working fluid guided to the communication groove 45 becomes smaller, and the difference between the load that the rotor 2 receives from the body-side side plate 30 side and the load that the rotor 2 receives from the cover-side side plate 40 side due to the pressure of the working fluid decreases. can be made smaller. This prevents the rotor 2 from coming into contact with the body-side side plate 30.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. do not have.

DESCRIPTION OF SYMBOLS 1... Drive shaft, 2... Rotor, 2s... Slit, 3... Vane, 3a... Tip part, 3b... Base end part, 4... Cam ring, 4a... Inner cam surface, 5... Back pressure chamber, 6... Pump chamber, 10... Pump body, 10A... Housing recess, 14... High pressure chamber, 20... Pump cover, 30... ... Body side side plate (first side member), 30a... First sliding surface, 31... First discharge port, 32... First through hole, 34... First back pressure groove , 34b, 34d...Discharge side first back pressure groove, 40...Cover side side plate (second side member), 40a...Second sliding surface, 41...Second discharge port, 42 ...Second through hole, 43...Second suction port (suction port), 44...Second back pressure groove, 44b, 44d...Second back pressure groove on discharge side, 45...Communication Groove, 50a, 50c... Suction area, 100... Vane pump, A... Inner dimension, B... Outer dimension

Claims (6)

a rotor that is rotationally driven;
a plurality of slits opening on the outer peripheral surface of the rotor;
a plurality of vanes slidably housed in the slit;
a cam ring having an inner circumferential cam surface with which the tip of the vane slides in contact as the rotor rotates;
a first side member provided in contact with one side of the cam ring;
a second side member provided in contact with the other side of the cam ring;
a pump chamber defined by the rotor, the cam ring, and a pair of adjacent vanes;
a back pressure chamber defined within the slit by a proximal end of the vane;
Each of the first side members has a plurality of first back pressure grooves that are open to a first sliding surface on which the rotor slides, communicate with the back pressure chamber, and are spaced apart from each other in the circumferential direction of the rotor. has
The second side member is
a plurality of second back pressure grooves each opening in a second sliding contact surface on which the rotor slides and communicating with the back pressure chamber, and provided in the same number as the plurality of first back pressure grooves;
a communication groove that is open to the second sliding contact surface and communicates the plurality of circumferentially adjacent second back pressure grooves;
The opening of each of the plurality of first back pressure grooves to the first sliding contact surface has a larger opening area than the opening of each of the plurality of second back pressure grooves to the second sliding contact surface. Features a vane pump. The vane pump according to claim 1,
The first back pressure groove is characterized in that a dimension in the radial direction of the rotor at the opening to the first sliding surface is larger than the opening of the second back pressure groove to the second sliding surface. vane pump. The vane pump according to claim 2,
The plurality of first back pressure grooves include a discharge side first back pressure groove provided in a discharge region where the volume of the pump chamber contracts,
The plurality of second back pressure grooves include a discharge side second back pressure groove provided in the discharge area,
The discharge side first back pressure groove and the discharge side second back pressure groove are provided so as to overlap each other in the axial direction of the rotor,
The first side member is provided with a first through hole through which a drive shaft for rotationally driving the rotor is inserted, and a first through hole in which the discharge side first back pressure groove is located between the first through hole and the first through hole. one discharge port;
The second side member includes a second through hole through which the drive shaft is inserted, and a second discharge port provided such that the discharge side second back pressure groove is located between the second through hole. have,
The second side member has an inner dimension that is the radial dimension between the discharge side second back pressure groove and the second through hole, and the discharge side second back pressure groove and the second discharge port. and an outer dimension that is the radial dimension between the two is provided larger than the other,
When the inner dimension is larger than the outer dimension, the discharge side first back pressure groove is provided such that the radial dimension between the first through hole and the first through hole is smaller than the inner dimension, When the outer dimension is larger than the inner dimension, the vane pump is provided so that the radial dimension between the vane pump and the first discharge port is smaller than the outer dimension. The vane pump according to any one of claims 1 to 3,
The plurality of first back pressure grooves are characterized in that a total opening area of the respective opening areas is the same as a total opening area of the plurality of second back pressure grooves and the communication groove. vane pump. The vane pump according to claim 1,
a pump body having an accommodation recess that accommodates the rotor, the cam ring, the first side member, and the second side member;
a pump cover that covers the housing recess and is fixed to the pump body;
further comprising a high-pressure chamber provided on the bottom side of the housing recess, defined by the pump body and the first side member, and storing high-pressure working fluid discharged from the pump chamber,
the first side member is provided between the rotor and the high pressure chamber,
The plurality of first back pressure grooves are characterized in that a total opening area of the respective opening areas is larger than a total opening area of the plurality of second back pressure grooves and the communication groove. vane pump. The vane pump according to claim 1,
The second side member further includes a suction port that guides working fluid into the pump chamber,
The vane pump, wherein the communication groove communicates with the suction port.

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