JP5783826B2 - Vane pump - Google Patents

Description

  The present invention relates to a vane pump used as a fluid pressure supply source.

  In this type of vane pump, a plurality of vanes are housed in radial slits of the rotor. Each vane is urged in the direction protruding from the slit by the pressure of the vane back pressure chamber that presses the base end portion and the centrifugal force that works as the rotor rotates, and the tip portion of the vane is an inner circumferential cam of the cam ring. Touch the surface. As the rotor rotates, the vane slidingly contacting the inner peripheral cam surface reciprocates, the pump chamber expands and contracts, and hydraulic oil pressurized in the pump chamber is discharged from the discharge port that opens in the side plate into the vane pump. It is discharged into the pressure chamber and supplied from the discharge pressure chamber to the hydraulic equipment.

  In such a vane pump, when the stopped state continues, the vane arranged at the top falls into the slit due to gravity, so if the operation of the vane that had fallen into the slit at the start-up protrudes from the slit is delayed, the pump discharge pressure A problem arises in that the rise of is delayed.

  As a countermeasure against this, in the one disclosed in Patent Document 1, a plate member (15) urged toward the side plate is interposed in the discharge pressure chamber (8), and the plate member (15) serves as a discharge port and a slit. A sealed oil chamber (17) communicating with the inner vane back pressure chamber (33) is formed.

  At startup, the entire amount of hydraulic oil discharged from the discharge port to the discharge pressure chamber (8) is supplied to the vane back pressure chamber (33), and the vane that has fallen into the slit due to gravity at the time of stop is prompted to protrude from the slit. .

  After startup, as the discharge pressure in the discharge pressure chamber (8) increases, the biased plate member (15) moves to open the discharge pressure chamber (8) and the discharge passage (discharge oil passage 9). The hydraulic oil discharged from the discharge port to the discharge pressure chamber (8) is supplied to the outside.

Japanese Patent Laid-Open No. 10-196557 (Patent No. 3759659)

  However, the vane pump has a problem in that the performance of the vane pump is impaired because the plate member (15) biased during operation imparts resistance to the hydraulic oil flowing through the discharge pressure chamber.

  The present invention has been made in view of the above problems, and provides a vane pump in which the pump discharge pressure rises quickly without using a plate member that provides resistance to the hydraulic fluid flowing through the discharge pressure chamber during operation. With the goal.

The present invention is a vane pump used as a fluid pressure supply source, a rotor that is rotationally driven, a plurality of slits that are radially formed in the rotor, and a plurality of vanes that slidably protrude from the slit, The vane back pressure chamber defined between the base end portion of the vane and the slit, the back pressure port communicating with the vane back pressure chamber, and the tip end portion of the vane are in sliding contact with the rotation of the rotor. Suction that guides the working fluid to the inner circumferential cam surface, a pump chamber defined between the inner circumferential cam surface and the outer circumferential surface of the rotor and adjacent vanes, and a pump chamber that expands as the rotor rotates. A pressure chamber, a discharge pressure chamber that guides a working fluid discharged from a pump chamber that contracts as the rotor rotates through a high-pressure port, to a fluid pressure supply destination, and a pump chamber that contracts as the rotor rotates. The resulting working flow It includes a back pressure passage leading to the vane back pressure chamber shorting the discharge chamber the pressure, and the backpressure passage includes a high pressure port in the discharge region where the pump chamber is contracted located in the lower part of the vane pump, the upper part of the vane pump And a back pressure port in the suction area where the pump chamber expands .

  According to the present invention, the working fluid pressure generated in the pump chamber at the time of startup is guided to the vane back pressure chamber via the back pressure passage, and the vane that has fallen into the slit protrudes from the slit by the pressure of the vane back pressure chamber. The pump discharge pressure rises promptly.

  The back pressure passage does not include the discharge pressure chamber, and the discharge pressure chamber is short-circuited so that the high pressure port and the back pressure port communicate with each other, so that resistance is given to the working fluid flowing through the discharge pressure chamber during operation. The vane pump performance is not impaired.

It is sectional drawing of the vane pump which shows embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is a front view of a cover side plate. It is sectional drawing of the vane pump which shows other embodiment. It is sectional drawing of the vane pump which shows other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  The vane pump 1 shown in FIGS. 1 to 4 is used as a hydraulic supply source for a hydraulic device mounted on a vehicle, for example, a power steering device or a transmission.

  The vane pump 1 uses a working oil (oil) as a working fluid, but a working fluid such as a water-soluble alternative liquid may be used instead of the working oil.

  In the vane pump 1, the power of an engine (not shown) is transmitted to the end of the drive shaft 9, and the rotor 2 connected to the drive shaft 9 rotates. The rotor 2 rotates in the direction indicated by the arrow in FIG.

  The drive shaft 9 is rotatably supported by the pump body 10 and the pump cover 50. The pump body 10 is formed with a pump housing recess 10a for housing the rotor 2, the cam ring 4, the body side plate 30, the cover side plate 40, and the like. A pump cover 50 is fastened to the pump body 10, and the pump housing recess 10 a is sealed by the pump cover 50.

  A discharge pressure chamber 18 is defined between the bottom of the pump housing recess 10 a of the pump body 10 and the body side plate 30. The body side plate 30 is pressed against the rear end surface of the cam ring 4 by the pump discharge pressure guided to the discharge pressure chamber 18, the front end surface of the cam ring 4 is pressed against the cover side plate 40, and the cover side plate The front end face of 40 is pressed against the pump cover 50 via a partition plate 55 described later.

  The vane pump 1 includes a plurality of vanes 3 provided so as to freely reciprocate in the rotational radial direction of the rotor 2, and a cam ring 4 in which the rotor 2 and the vanes 3 are accommodated and the tip of the vane 3 slides as the rotor 2 rotates. With.

  In the rotor 2, a plurality of slits 5 are formed radially at a predetermined interval. The slit 5 has an opening on the outer peripheral surface of the rotor 2. The vane 3 has a rectangular plate shape and is slidably inserted into the slit 5.

  Inside the cam ring 4, a plurality of pump chambers 7 are defined by the outer peripheral surface of the rotor 2, the inner peripheral cam surface 4 a of the cam ring 4, the outer peripheral surface of the rotor 2 and the adjacent vanes 3.

  The cam ring 4 is an annular member whose inner circumferential cam surface 4a has a substantially oval shape. As the rotor 2 makes one revolution, each vane 3 following the inner peripheral cam surface 4a reciprocates twice.

  As shown in FIG. 2, the vane pump 1 is divided into a first suction / discharge region in which the vane 3 reciprocates for the first time, and a second suction / discharge region in which the vane 3 reciprocates for the second time. It is done. The pump chamber 7 expands in the first suction region, contracts in the first discharge region, expands in the second suction region, and contracts in the second discharge region.

  As described above, the vane pump 1 has two suction regions and two discharge regions, but is not limited thereto, and may be configured to have one or three or more suction regions and one or three or more discharge regions. Good.

  The first suction ports 31 and 41 are opened in the first suction area, and the second suction area is opened in each end surface of the body side plate 30 and the cover side plate 40 where the rotor 2 is in sliding contact. The two suction ports 32 and 42 are opened. A suction pressure chamber 51 is defined by the pump cover 50. The suction pressure chamber 51 communicates with the first suction ports 31 and 41 and the second suction ports 32 and 42. The suction pressure chamber 51 is communicated with the tank 12 through the suction passage 11.

  When the vane pump 1 is operated, the hydraulic oil in the tank 12 passes through the suction passage 11, the suction pressure chamber 51, the first suction ports 31 and 41, and the second suction ports 32 and 42 as indicated by arrows in FIG. 1. The pump chamber 7 is supplied in order.

  A first discharge port (not shown) is opened in the first discharge region on the end surface of the body side plate 30 where the rotor 2 is slidably contacted, and a second discharge port (see FIG. (Not shown) are opened.

  A discharge pressure chamber 18 is defined between the pump body 10 and the body side plate 30. A first discharge port and a second discharge port are opened in the discharge pressure chamber 18, respectively. The discharge pressure chamber 18 communicates with a hydraulic device (fluid pressure supply destination) 14 via the discharge passage 13.

  When the vane pump 1 is operated, the pressurized hydraulic oil discharged from the pump chamber 7 is supplied to the hydraulic device 14 through the first discharge port, the second discharge port, the discharge pressure chamber 18, and the discharge passage 13 in this order. . The hydraulic oil discharged from the hydraulic device 14 is returned to the tank 12 through the return passage 15.

  A vane back pressure chamber 6 is defined between the rear end of the slit 5 and the base end of the vane 3. The vane 3 is urged in the direction protruding from the slit 5 by the pressure of the vane back pressure chamber 6 that presses the base end portion thereof and the centrifugal force that works as the rotor 2 rotates, and the tip end portion of the vane 3 is cam ring 4. Is in sliding contact with the inner circumferential cam surface 4a.

  Four back pressure ports 33 are formed on the end surface of the body side plate 30 where the rotor 2 is in sliding contact. Each back pressure port 33 extends side by side in an arc shape centering on the rotation axis of the rotor 2, and the vane back pressure in the first suction region, the first discharge region, the second suction region, and the second discharge region. Each communicates with the chamber 6.

  The body-side side plate 30 is formed with a plurality of discharge pressure introduction through holes 34 that allow the discharge pressure chamber 18 and the back pressure ports 33 to communicate with each other. During the operation of the vane pump 1, the pump discharge pressure generated in the discharge pressure chamber 18 is guided to each vane back pressure chamber 6 from each discharge pressure introduction through hole 34, and the vane 3 is attached in a direction in which the vane 3 protrudes from the slit 5 by this pump discharge pressure. Be forced.

  The vane pump 1 is mounted such that the second suction region and the second discharge region are upward (see the arrow in FIG. 2), and the first suction region and the first discharge region are downward.

  If the stop state of the vane pump 1 continues, as shown in FIG. 2, the second suction region located in the upper portion of the vane pump 1 and the vane 3 in the second discharge region fall into the interior of each slit 5 by gravity. On the other hand, the vane 3 in the first suction region and the first discharge region located in the lower portion of the vane pump 1 is maintained in a state where it protrudes from each slit 5 by gravity and is in contact with the inner peripheral cam surface 4a.

  When the vane pump 1 is started, the pump discharge pressure generated in the discharge pressure chamber 18 is guided to the vane back pressure chamber 6 from the discharge pressure introduction through hole 34, and the vane 3 tries to protrude from the slit 5 by this pump discharge pressure. Since it takes time for the pump discharge pressure of the discharge pressure chamber 18 having a volume to rise, it takes time for each vane 3 that has fallen into each slit 5 to protrude from each slit 5, and the pump discharge pressure rises. The problem of being delayed arises.

  In response to this, the vane pump 1 is provided with first and second back pressure passages 20 and 25 that connect the pump chamber 7 and the vane back pressure chamber 6 to the pump cover 50 and the cover side plate 40 side. . The first and second back pressure passages 20, 25 do not include the discharge pressure chamber 18, but short-circuit the discharge pressure chamber 18 to connect the pump chamber 7 and the vane back pressure chamber 6. In other words, the first and second back pressure passages 20 and 25 bypass the discharge pressure chamber 18 and connect the pump chamber 7 and the vane back pressure chamber 6.

  Thus, when the vane pump 1 is started, the high pressure generated in the pump chamber 7 is guided to the vane back pressure chamber 6 from the first and second back pressure passages 20 and 25 that short-circuit the discharge pressure chamber 18. The pressure of the pressure chamber 6 rises quickly, and the vanes 3 that have fallen into the slits 5 in the second suction region quickly protrude.

  Hereinafter, a specific configuration relating to the first and second back pressure passages 20 and 25 will be described.

  As shown in FIG. 4, four back pressure ports 45 to 48 are formed on the end surface of the cover side plate 40 where the rotor 2 is in sliding contact. Each of the back pressure ports 45 to 48 is formed in a groove shape extending in an arc shape around the rotation axis of the rotor 2, and includes a first suction region, a first discharge region, a second suction region, and a second discharge. Each area opens to face the vane back pressure chamber 6.

  Two high-pressure ports 43 and 44 are formed on the end surface of the cover side plate 40 where the rotor 2 is in sliding contact. Each of the high-pressure ports 43 and 44 is formed in a groove shape extending in an arc shape around the rotation axis of the rotor 2, and opens to face the pump chamber 7 in the first discharge region and the second discharge region.

  The first back pressure passage 20 includes a through hole 21 that opens to the high pressure port 43 in the first discharge region, a groove 22 that opens to the end surface 49 of the cover side plate 40 on the pump cover 50 side, and a second suction port. It is comprised by the through-hole 23 opened to the back pressure port 46 of an area | region, and connects the high pressure port 43 of a 1st discharge area | region, and the back pressure port 46 of a 2nd suction area | region.

  The second back pressure passage 25 includes a through hole 26 opened to the high pressure port 44 in the second discharge region, a groove 27 opened to the end surface 49 on the pump cover 50 side in the cover side plate 40, and a first suction. It is constituted by a through hole 28 opened to the back pressure port 48 in the region, and communicates the high pressure port 44 in the second discharge region and the back pressure port 48 in the first suction region.

  As shown in FIG. 3, a partition plate 55 is interposed between the cover side plate 40 and the pump cover 50. A partition plate 55 partitions the second back pressure passage 25 and the suction pressure chamber 51.

  The suction pressure chamber 51 extends in an inverted V shape in FIG. 2, and the hydraulic oil guided through the suction passage 11 is divided and guided to the first suction port 41 and the second suction port 42. . For this reason, the suction pressure chamber 51 is provided at a position overlapping with a part of the second back pressure passage 25 in FIG. However, by partitioning the second back pressure passage 25 and the suction pressure chamber 51 by the partition plate 55, it is possible to prevent the hydraulic oil in the second back pressure passage 25 from leaking into the suction pressure chamber 51.

  As described above, in order to provide the second back pressure passage 25, it is necessary to provide the partition plate 55.

  The vane pump 1 is configured as described above. When the vane pump 1 is started, the vanes 3 protruding from the slits 5 in the first discharge region are pushed into the slits 5 following the inner peripheral cam surface 4a, and the pump chamber 7 contracts. 7 hydraulic pressure rises. In this way, the high pressure generated in the pump chamber 7 is guided from the first back pressure passage 20 to the back pressure port 46 in the second suction region, so that the pressure in the vane back pressure chamber 6 in the second suction region quickly rises. In the second suction region, each vane 3 that has fallen into each slit 5 protrudes, and the tip of each vane 3 slides into contact with the inner circumferential cam surface 4a so that the pump chamber 7 is quickly defined. Done.

  That is, the operating oil pressure generated in the pump chamber 7 in the first discharge region urges the vanes 3 that have fallen into the slits 5 in the second suction region to protrude, and the pump discharge guided to the discharge pressure chamber 18. The time taken for the pressure to rise can be shortened.

  When the vane pump 1 is activated, the operation of contracting the pump chamber 7 cannot be obtained in a state where each vane 3 falls into the slit 5 due to gravity in the second discharge region. Therefore, in order to improve the startability of the vane pump 1, only the first back pressure passage 20 may be provided, and the second back pressure passage 25 may not be provided.

  As described above, when only the first back pressure passage 20 is provided and the second back pressure passage 25 is not provided, a partition is formed between the cover side plate 40 and the pump cover 50 as shown in FIG. There is no need to provide a plate. As described above, the partition plate 55 shown in FIGS. 1 and 4 stops the hydraulic oil in the second back pressure passage 25 from leaking into the suction pressure chamber 51. When it is not provided, the partition plate 55 can be eliminated. As shown in FIG. 5, when the partition plate is abolished, the first back pressure passage 20 is defined by the groove 22 and the like opened in the end surface 49 of the cover side plate 40 and the end surface of the pump cover 50. The As a result, the hydraulic oil in the first back pressure passage 20 is prevented from leaking into the suction pressure chamber 51.

  Next, another embodiment shown in FIG. 6 will be described. This has basically the same configuration as the embodiment of FIGS. 1-4, and only the differences will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  In the vane pump 1 shown in FIG. 6, the vane back pressure chamber 6 communicates with the pump chambers 7 in the first and second discharge regions only through the first and second back pressure passages 20 and 25, and the body side plate The 30 side is configured not to communicate with the discharge pressure chamber 18. That is, the body-side side plate 30 is not formed with the discharge pressure introduction through hole 34 in the embodiment. In other words, the vane back pressure chamber 6 communicates with the discharge pressure chamber 18 only through the first and second back pressure passages 20 and 25, the pump chamber 7, and the discharge port (not shown).

  In this case, when the vane pump 1 is started, the hydraulic oil in each vane back pressure chamber 6 is suppressed from flowing into the discharge pressure chamber 18, and the time taken for the pressure in the vane back pressure chamber 6 to rise can be further shortened. .

  During operation, high pressure is guided from the high pressure ports 43 and 44 to the back pressure ports 45 to 48. Each vane 3 is urged in a direction protruding from the slit 5 by a pressure guided from each back pressure port 45 to 48 to each vane back pressure chamber 6 and a centrifugal force acting as the rotor 2 rotates.

  Hereinafter, the gist, action, and effect of the present invention will be described.

  (A) The present invention is a vane pump 1 used as a fluid pressure supply source, which is a rotor 2 that is rotationally driven, a plurality of slits 5 that are radially formed in the rotor 2, and that can be slid from the slits 5. A plurality of vanes 3 projecting from the vane 3, the vane back pressure chamber 6 defined between the base end of the vane 3 and the slit 5, and the tip of the vane 3 sliding as the rotor 2 rotates. The inner circumferential cam surface 4a in contact, the pump chamber 7 defined between the inner circumferential cam surface 4a and the outer circumferential surface of the rotor 2 and the adjacent vane 3, and a pump that expands as the rotor 2 rotates. A suction pressure chamber 51 that guides the working fluid to the chamber 7; a discharge pressure chamber 18 that guides the working fluid discharged from the pump chamber 7 that contracts as the rotor 2 rotates to the fluid pressure supply destination (hydraulic device 14); The pon that contracts as the rotor 2 rotates A back pressure passage 20, 25 leading to the vane back-pressure chamber 6 by shorting discharge chamber 18 the hydraulic fluid pressure generated in the chamber 7, and a structure comprising a.

  Based on the above configuration, the working fluid pressure generated in the pump chamber 7 at the time of startup is guided to the vane back pressure chamber 6 via the back pressure passages 20 and 25, and the vane 3 that has fallen into the slit 5 is the pressure in the vane back pressure chamber 6. Thus, it is urged to protrude from the slit 5, the pump discharge pressure rises quickly, and the startability is improved.

  The back pressure passages 20 and 25 do not include the discharge pressure chamber 18 and are configured to communicate with the high pressure ports 43 and 44 and the back pressure ports 46 and 48 by short-circuiting the discharge pressure chamber 18. No resistance is given to the working fluid flowing through the vane pump 1, and the performance of the vane pump 1 is not impaired.

  (A) The present invention includes high-pressure ports 43 and 44 that communicate with the pump chamber 7 that contracts as the rotor 2 rotates, and back-pressure ports 46 and 48 that communicate with the vane back-pressure chamber 6. The back pressure passages 20 and 25 are configured to communicate the high pressure ports 43 and 44 with the back pressure ports 46 and 48.

  Based on the above configuration, the working fluid pressure generated in the pump chamber 7 is guided to the vane back pressure chamber 6 through the high pressure ports 43 and 44, the back pressure passages 20 and 25, and the back pressure ports 46 and 48.

  (C) The present invention includes two side plates 30 and 40 provided so as to sandwich the rotor 2 and the vane 3, the discharge pressure chamber 18 is defined by one side plate 30, and the back plate 40 is defined by the other side plate 40. The pressure passages 20 and 25 are defined.

  Based on the above configuration, the discharge pressure chamber 18 and the back pressure passages 20 and 25 can be provided across the rotor 2 and the vane 3 in a limited space in the vane pump 1, and the passage of the back pressure passages 20 and 25 is interrupted. A sufficient area is ensured and the enlargement of the vane pump 1 can be avoided.

  (D) The present invention accommodates the body side plate 30 and the cover side plate 40 provided so as to sandwich the rotor 2 and the vane 3, and the rotor 2, the cam ring 4, the body side plate 30 and the cover side plate 40. A pump body 10 having a pump housing recess 10a and a pump cover 50 for sealing the pump housing recess 10a, and a discharge pressure chamber 18 is defined between the body side plate 30 and the pump body 10. The back side passages 20 and 25 are defined by the cover side plate 40.

  Based on the above configuration, the discharge pressure chamber 18 and the back pressure passages 20 and 25 can be provided across the rotor 2 and the vane 3 in a limited space in the vane pump 1, and the passage of the back pressure passages 20 and 25 is interrupted. A sufficient area is ensured and the enlargement of the vane pump 1 can be avoided.

  (E) In the present invention, a suction pressure chamber 51 is defined between the cover side plate 40 and the pump cover 50, and the partition plate 55 interposed between the cover side plate 40 and the pump cover 50 is provided. The back pressure passages 20 and 25 and the suction pressure chamber 51 are partitioned by the partition plate 55.

  Based on the above configuration, the back pressure passages 20 and 25 and the suction pressure chamber 51 can be provided in a limited space in the vane pump 1 without communicating with each other, and the back pressure passages 20 and 25 and the suction pressure chamber 51 can be provided. Enough passage cross-sectional areas are ensured, respectively, and enlargement of the vane pump 1 can be avoided.

(F) In the present invention, the back pressure passage 20 is located at the lower portion of the vane pump 1 and the high pressure port 43 in the discharge region where the pump chamber 7 contracts, and the suction at which the pump chamber 7 extends at the upper portion of the vane pump 1 The region is configured to communicate with the back pressure port 46 in the region.

  Based on the above configuration, the hydraulic pressure generated in the pump chamber 7 that is located below the vane pump 1 and contracts via each vane 3 that protrudes from each slit 5 falls into each slit 5 located above the vane pump 1. Each vane 3 that has come out is urged to protrude, the pump discharge pressure rises quickly, and the startability is improved.

  (G) In the present invention, the vane back pressure chamber 6 communicates with the pump chamber 7 only through the back pressure passages 20 and 25.

  Based on the above configuration, it is possible to suppress the working fluid in the vane back pressure chamber 6 from flowing out to the discharge pressure chamber 18 at the time of activation, and to further reduce the time required for the pressure in the vane back pressure chamber 6 to rise.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  In the present embodiment, a part of the back pressure passage 20 is defined by the groove 22 of the cover-side side plate 40 and the end face of the partition plate 55 or the pump cover 50. The back pressure passage 20 may be defined only by the through holes formed in the side plate 40.

  In the above-described embodiment, the back pressure ports 46 and 48, the high pressure ports 43 and 44, and the back pressure passage 20 are each formed in the cover side plate 40. It is good also as a structure which abolishes and forms these in the pump cover 50. FIG.

  In the embodiment, the discharge port (not shown) is formed in the body side plate 30, and the back pressure ports 46 and 48, the high pressure ports 43 and 44, and the back pressure passage 20 are formed in the cover side plate 40. However, the present invention is not limited to this, and the back pressure ports 46 and 48, the high pressure ports 43 and 44, and the back pressure passage 20 may be formed in the body side plate 30 together with the discharge port (not shown).

  The vane pump of the present invention is not limited to a hydraulic device mounted on a vehicle, and can be used as a fluid pressure supply source for driving a load of, for example, a construction machine, a work machine, another machine, or a facility.

DESCRIPTION OF SYMBOLS 1 Vane pump 2 Rotor 3 Vane 4a Inner peripheral cam surface 5 Slit 6 Vane back pressure chamber 7 Pump chamber 10 Pump body 10a Pump accommodation recessed part 11 Suction passage 12 Tank 13 Discharge passage 14 Hydraulic equipment (fluid pressure supply destination)
18 Discharge pressure chamber 20, 25 Back pressure passage 30 Body side plate 33 Back pressure port 34 Discharge pressure introduction hole 40 Cover side side plate 41 Suction port 42 Suction port 43, 44 High pressure port 45-48 Back pressure port 50 Pump cover 51 Suction pressure chamber

Claims (5)

A vane pump used as a fluid pressure supply source,
A rotor that is driven to rotate;
A plurality of slits formed radially in the rotor;
A plurality of vanes protruding slidably from the slit;
A vane back pressure chamber defined between the base end of the vane and the slit;
A back pressure port communicating with the vane back pressure chamber;
An inner peripheral cam surface with which the tip of the vane slides as the rotor rotates,
A pump chamber defined between the inner circumferential cam surface and the outer circumferential surface of the rotor and the adjacent vanes;
A suction pressure chamber that guides the working fluid to the pump chamber that expands as the rotor rotates;
A discharge pressure chamber for guiding a working fluid discharged from the pump chamber through the high pressure port to contract as the rotor rotates to a fluid pressure supply destination;
A back pressure passage that shorts the discharge pressure chamber and guides the working fluid pressure generated in the pump chamber that contracts as the rotor rotates to the vane back pressure chamber ,
The back pressure passage is located at the lower part of the vane pump and the high pressure port in the discharge region where the pump chamber contracts, and the back pressure port in the suction region which is located above the vane pump and expands the pump chamber. A vane pump characterized by communicating with each other. Comprising two side plates provided so as to sandwich the rotor and the vane;
The discharge pressure chamber is defined by one of the side plates,
The vane pump according to claim 1, wherein the back pressure passage is defined by the other side plate . A body-side side plate and a cover-side side plate provided so as to sandwich the rotor and the vane;
A pump body having a pump housing recess in which the rotor, the cam ring having the inner circumferential cam surface, the body side plate and the cover side plate are housed;
A pump cover for sealing the pump housing recess,
The discharge pressure chamber is defined between the body side plate and the pump body,
The vane pump according to claim 1 or 2, wherein the back pressure passage is defined by the cover side plate . The suction pressure chamber is defined between the cover side plate and the pump cover,
A partition plate interposed between the cover side plate and the pump cover;
The vane pump according to claim 3, wherein the back pressure passage and the suction pressure chamber are partitioned by the partition plate . The vane pump according to any one of claims 1 to 4, wherein the vane back pressure chamber communicates with the pump chamber only through the back pressure passage .

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