CN113950580A

CN113950580A - Vane pump device

Info

Publication number: CN113950580A
Application number: CN202080042993.2A
Authority: CN
Inventors: 多贺直哉
Original assignee: Hitachi Astemo Ltd
Current assignee: Hitachi Astemo Ltd
Priority date: 2018-07-31
Filing date: 2020-06-16
Publication date: 2022-01-18
Also published as: US20220106957A1; WO2021019938A1; WO2020026338A1; JPWO2020026338A1

Abstract

The vane pump device comprises: a rotor which rotatably supports 10 blades so as to be movable in a rotation radius direction; and a cam ring having an inner circumferential surface facing the outer circumferential surface of the rotor, wherein the cam ring is configured to change a volume of the pump chamber according to a rotation angle by changing a distance from a rotation center of the rotor to the inner circumferential surface of the cam ring according to the rotation angle of the rotor, and thereby to shift to at least a suction step of sucking the working fluid into the pump chamber and a discharge step of discharging the working fluid from the pump chamber, and when an angle obtained by equally dividing a rotation angle of a downstream-side end portion forming the discharge port and a rotation angle of an upstream-side end portion forming the suction port is set as a central angle, a rotation angle difference between a start angle, which is a rotation angle at which the distance starts to increase, and the central angle is 2.5 degrees or less after a predetermined rotation angle passes through a section having the same distance.

Description

Vane pump device

Technical Field

The present invention relates to a vane pump device.

Background

The vane pump described in patent document 1 includes: a rotor coupled to a rotating shaft pivotally supported inside the housing to rotate; a cam ring disposed so as to surround the rotor inside the housing; a plurality of vanes slidably disposed in vane grooves provided in a radial direction of the rotor; a plurality of pump chambers divided by adjacent vanes around the rotor; and a plurality of discharge ports provided to face each other in a radial direction of the rotor, corresponding to the pump chambers that perform the compression stroke. In the vane pump described in patent document 1, a recess is formed in the rotor so as to be recessed from the outer peripheral surface toward the rotation center.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-50067

Disclosure of Invention

Problems to be solved by the invention

In the discharge step, if the discharge step is completed without completely discharging the high-pressure working fluid, the pressure of the pump chamber remains high despite the completion of the discharge step. When the suction process is started, if the pressure of the pump chamber is higher than the pressure of the suction port, the working fluid in the pump chamber flows backward to the suction port. When the reverse flow occurs, the suction port communicates with the pump chamber, and the working fluid is not immediately sucked into the pump chamber from the suction port, and there is a possibility that the start of suction into the pump chamber is delayed. Therefore, the pressure of the pump chamber at the start of the suction process is desirably low.

The invention aims to provide a vane pump device capable of reducing the pressure of a pump chamber at the beginning of a suction process.

Means for solving the problems

The present invention accomplished in view of the above object is a vane pump device including: a rotor which rotatably supports 10 blades so as to be movable in a rotation radius direction; and a cam ring having an inner circumferential surface facing the outer circumferential surface of the rotor, wherein a distance from a rotation center of the rotor to the inner circumferential surface of the cam ring is changed according to a rotation angle of the rotor, whereby a volume of a pump chamber defined by the outer circumferential surface of the rotor, the inner circumferential surface of the cam ring, and adjacent 2 vanes of the plurality of vanes is changed according to the rotation angle, whereby at least a suction step of sucking a working fluid into the pump chamber and a discharge step of discharging the working fluid from the pump chamber are shifted, and when an angle at which the rotation angle forming a downstream end of a discharge port and the rotation angle forming an upstream end of the suction port are equally divided is set as a central angle, after a section having the same distance passes a predetermined rotation angle, the rotation angle at which the distance starts to increase, that is a start angle relative to the central angle The degree difference is less than 2.5 degrees.

Effects of the invention

According to the present invention, it is possible to provide a vane pump device capable of reducing the pressure of a pump chamber at the start of a suction process.

Drawings

Fig. 1 is a perspective view of a part of components of the vane pump viewed from the cover side.

Fig. 2 is a perspective view of a part of the components of the vane pump viewed from the casing side.

Fig. 3 is a sectional view showing a flow path of high-pressure oil of the vane pump.

Fig. 4 is a sectional view showing a flow path of low-pressure oil of the vane pump.

Fig. 5 is a view of the rotor, the vanes, and the cam ring viewed in one direction of the rotation axis direction and a view of the rotor, the vanes, and the cam ring viewed in the other direction of the rotation axis direction.

Fig. 6 is a diagram showing the distance of the cam ring inner peripheral surface of the cam ring from the rotation center for each rotation angle.

Fig. 7 is a view of the inner plate viewed in one direction and the other direction of the rotation axis direction.

Fig. 8 is a view of the outer plate viewed in the other direction and one direction of the rotation axis direction.

Fig. 9 is a view of the housing viewed in one direction of the rotation axis direction.

Fig. 10 is a view of the cam ring and the inner plate viewed in one direction.

Fig. 11 is a view of the cam ring and the outer plate viewed in another direction.

Fig. 12 is a view showing a part of the inner peripheral surface of the cam ring having a different starting point angle.

Fig. 13 is a simulation result showing the discharge flow rate in the case where the starting point angle is changed.

Fig. 14 is a diagram showing a part of the change in the volume of the pump chamber at different starting point angles.

Fig. 15 is a graph showing a correlation between the starting point angle and the pump capacity.

Fig. 16 is a view showing a part of the cam ring inner peripheral surface of modification 2.

Detailed Description

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

Fig. 1 is a perspective view of a part of the components of a vane pump device 1 (hereinafter referred to as a "vane pump 1") according to an embodiment, as viewed from a cover 120 side.

Fig. 2 is a perspective view of a part of the components of the vane pump 1 viewed from the casing 110 side.

Fig. 3 is a sectional view showing a flow path of high-pressure oil in the vane pump 1. Fig. 3 is also a sectional view of the section III-III of fig. 5.

Fig. 4 is a sectional view showing a low-pressure oil flow path of the vane pump 1. Fig. 4 is also a cross-sectional view of section IV-IV of fig. 5.

The vane pump 1 is driven by power from an engine of a vehicle, for example, and is a pump for supplying oil, which is an example of a working fluid, to a device such as a hydraulic continuously variable transmission or a hydraulic power steering apparatus.

Further, the vane pump 1 discharges oil sucked from the 1 suction port 116 from the 1 st discharge port 117 and the 2 nd discharge port 118, which are different from each other, from the 2 nd discharge port. The pressures of the oil discharged from the 1 st drain 117 and the 2 nd drain 118 may be the same or different. More specifically, the vane pump 1 increases the pressure of oil sucked from the suction port 116 and sucked into the pump chamber from the 1 st suction port 2 (see fig. 3) in the pump chamber, discharges the oil from the 1 st discharge port 4 (see fig. 3), and discharges the oil from the 1 st discharge port 117 to the outside. The vane pump 1 increases the pressure of the oil sucked from the suction port 116 and sucked into the pump chamber from the 2 nd suction port 3 (see fig. 4), discharges the oil from the 2 nd discharge port 5 (see fig. 4), and discharges the oil from the 2 nd discharge port 118 to the outside. In addition, the 1 st suction port 2, the 2 nd suction port 3, the 1 st discharge port 4, and the 2 nd discharge port 5 are portions facing (facing) the pump chamber.

The vane pump 1 includes: a rotary shaft 10 that rotates upon receiving a driving force from an engine, a motor, or the like of a vehicle; a rotor 20 that rotates together with the rotary shaft 10; a plurality of blades 30 assembled in a groove formed in the rotor 20; and a cam ring 40 surrounding the outer circumferences of the rotor 20 and the vanes 30.

Further, the vane pump 1 includes: an inner plate 50, which is an example of a one-side member, disposed on one end portion side of the cam ring 40 with respect to the rotary shaft 10; and an outer plate 60 as an example of the other side member, which is disposed on the other end portion side of the rotary shaft 10 with respect to the cam ring 40.

Further, the vane pump 1 has a casing 100 that houses the rotor 20, the plurality of vanes 30, the cam ring 40, the inner plate 50, and the outer plate 60. The case 100 has a bottomed cylindrical case 110 and a cover 120 covering an opening of the case 110.

< Structure of rotating shaft 10 >

The rotary shaft 10 is rotatably supported by a housing-side bearing 111, described later, provided in the housing 110 and a cover-side bearing 121, described later, provided in the cover 120. A spline 11 is formed on the outer peripheral surface of the rotary shaft 10, and the rotary shaft 10 is coupled to the rotor 20 via the spline 11. In the present embodiment, the rotary shaft 10 is rotated by receiving power from a drive source disposed outside the vane pump 1 such as an engine of a vehicle, for example, and the rotor 20 is rotationally driven via the spline 11.

In the vane pump 1 according to embodiment 1, the rotary shaft 10 (the rotor 20) is configured to rotate clockwise in fig. 1.

< Structure of rotor 20 >

Fig. 5 is a view of the rotor 20, the vanes 30, and the cam ring 40 viewed in one direction and the other direction of the rotation axis direction.

The rotor 20 is a member having a substantially cylindrical shape. A spline 21 into which a spline 11 (see fig. 1) of the rotary shaft 10 is fitted is formed on the inner circumferential surface of the rotor 20. The rotor 20 has an arc-shaped curved surface portion 22 around the rotation center C of the rotary shaft 10 on the outer peripheral portion. Further, a plurality of (10 in the present embodiment) vane grooves 23 that are recessed from the outer circumferential surface of the rotor 20 in the direction of the rotation center C and that house the vanes 30 are formed at equal intervals (radially) in the circumferential direction on the outer circumferential portion of the rotor 20. Further, a rotor recess 24, which is an example of a 1 st recess recessed from the curved surface portion 22 toward the rotation center C side, is formed in the outer peripheral portion of the rotor 20.

The curved surface portion 22 is formed between the adjacent 2 vane grooves 23.

The vane grooves 23 are grooves that open on the outer peripheral surface of the rotor 20 and on both end surfaces of the rotating shaft 10 in the rotating shaft direction. When viewed in the direction of the rotation axis, as shown in fig. 5, the outer peripheral portion side of the vane groove 23 is a rectangle whose rotation radius direction is the longitudinal direction, and the rotation center C side is a circle having a diameter larger than the length of the rectangle in the short side direction. That is, the vane groove 23 includes a rectangular parallelepiped groove 231 formed in a rectangular parallelepiped shape on the outer peripheral portion side and a cylindrical groove 232 as an example of a center side space formed in a cylindrical shape on the rotation center C side.

The rotor recesses 24 are formed at both ends in the rotation axis direction, respectively. The rotor recess 24 is formed in the circumferential center of the curved surface 22. The rotor recess 24 has a chamfered shape gradually toward the rotation center C from the center toward the end in the rotation axis direction.

< Structure of vane 30 >

The blades 30 are rectangular parallelepiped members, and 1 blade is assembled in each of the blade grooves 23 of the rotor 20. The length of the vane 30 in the rotation radial direction is smaller than the length of the vane groove 23 in the rotation radial direction, and the width is smaller than the width of the vane groove 23. The vane 30 is held in the vane groove 23 so as to be movable in the radial direction of rotation.

< Structure of cam ring 40 >

The cam ring 40 is a substantially cylindrical member, and has a cam ring outer peripheral surface 41, a cam ring inner peripheral surface 42, an inner end surface 43 that is an end surface on the inner plate 50 side in the rotation axis direction, and an outer end surface 44 that is an end surface on the outer plate 60 side in the rotation axis direction.

When viewed in the rotation axis direction, as shown in fig. 5, the cam ring outer peripheral surface 41 has a substantially circular shape whose distance from the rotation center C is substantially equal over the entire circumference (excluding a part thereof).

In addition, the vane pump 1 has 10

vanes

30, and 10 pump chambers are formed by the adjacent 2 vanes 30, the outer peripheral surface of the rotor 20 between these adjacent 2 vanes 30, the cam ring inner peripheral surface 42 between these adjacent 2 vanes 30, the inner plate 50, and the outer plate 60 by the contact of the 10 vanes 30 with the cam ring inner peripheral surface 42 of the cam ring 40. In the following description, the vane 30 on the upstream side in the rotation direction among the 2 vanes 30 constituting the pump chamber is referred to as an upstream-side vane, and the vane 30 on the downstream side in the rotation direction is referred to as a downstream-side vane. For example, in fig. 5, the upstream vane of the 2 vanes 30 constituting the pump chamber positioned on the vertical axis is denoted by the reference numeral "31", and the downstream vane is denoted by the reference numeral "32".

Fig. 6 is a diagram showing a distance L of the cam ring inner peripheral surface 42 of the cam ring 40 from the rotation center C for each rotation angle.

As shown in fig. 6, the cam ring inner peripheral surface 42 of the cam ring 40 is formed so that 2 convex portions exist at a distance L (in other words, a projecting amount of the vane 30 from the vane groove 23) from a rotation center C (see fig. 5) of each rotation angle when viewed in the rotation axis direction. That is, the distance L from the rotation center C is set such that, in the case where the positive vertical axis in the drawing viewed in one direction shown in fig. 5 is set to zero degrees, the 1 st convex portion 42a is formed by gradually becoming larger from about 20 degrees to about 90 degrees and gradually becoming smaller from about 90 degrees to about 160 degrees in the counterclockwise rotation direction, and the 2 nd convex portion 42b is formed by gradually becoming larger from about 200 degrees to about 270 degrees and gradually becoming smaller from about 270 degrees to about 340 degrees. In the cam ring 40 of the present embodiment, the 2 projections 42a and the projections 42b are the same in shape.

In the following description, the rotation angle of the end portion on the downstream side forming the 1 st discharge port 4 and the rotation angle of the end portion on the upstream side forming the 2 nd suction port 3 at the center, and the rotation angle of the end portion on the downstream side forming the 2 nd discharge port 5 and the rotation angle of the end portion on the upstream side forming the 1 st suction port 2 at the center may be referred to as "center angles".

As shown in fig. 5, a plurality of concave portions, i.e., inner concave portions 430, which are concave from the inner end surface 43, and a plurality of concave portions, i.e., outer concave portions 440, which are concave from the outer end surface 44 are formed on the cam ring 40.

As shown in fig. 5, the inner concave portion 430 has a 1 st suction concave portion 431 constituting a 1 st suction port 2, a 2 nd suction concave portion 432 constituting a 2 nd suction port 3, a 1 st discharge concave portion 433 constituting a 1 st discharge port 4, and a 2 nd discharge concave portion 434 constituting a 2 nd discharge port 5. The 1 st suction recess 431 and the 2 nd suction recess 432 are formed to be point-symmetrical with respect to the rotation center C, and the 1 st discharge recess 433 and the 2 nd discharge recess 434 are formed to be point-symmetrical with respect to the rotation center C, as viewed in the rotation axis direction. In addition, the 1 st suction recess 431 and the 2 nd suction recess 432 are recessed in the entire region of the inner end surface 43 in the rotational radius direction, and are recessed from the inner end surface 43 by a predetermined angle in the circumferential direction. The 1 st and 2 nd discharge recesses 433 and 434 are recessed from the inner end surface 43 by a predetermined range from the cam ring inner peripheral surface 42 to the cam ring outer peripheral surface 41 in the rotational radius direction, and are recessed from the inner end surface 43 by a predetermined angle in the circumferential direction.

As shown in the drawing viewed in the other direction shown in fig. 5, the outer recess 440 has a 1 st suction recess 441 constituting a 1 st suction port 2, a 2 nd suction recess 442 constituting a 2 nd suction port 3, a 1 st discharge recess 443 constituting a 1 st discharge port 4, and a 2 nd discharge recess 444 constituting a 2 nd discharge port 5. The 1 st suction recess 441 and the 2 nd suction recess 442 are formed to be point-symmetrical with respect to the rotation center C, and the 1 st discharge recess 443 and the 2 nd discharge recess 444 are formed to be point-symmetrical with respect to the rotation center C, when viewed in the rotation axis direction. In addition, the 1 st suction recess 441 and the 2 nd suction recess 442 are recessed in the entire region of the outer end surface 44 in the rotational radius direction, and are recessed from the outer end surface 44 by a prescribed angle in the circumferential direction. The 1 st and 2 nd discharge recesses 443, 444 are recessed from the outer end surface 44 in the rotational radius direction by a prescribed range from the cam ring inner peripheral surface 42 to the cam ring outer peripheral surface 41, and are recessed from the outer end surface 44 in the circumferential direction by a prescribed angle.

In addition, when viewed in the rotation axis direction, the 1 st suction recess 431 and the 1 st suction recess 441 are provided at the same position, and the 2 nd suction recess 432 and the 2 nd suction recess 442 are provided at the same position. In the case where the positive vertical axis in the drawing viewed in one direction shown in fig. 5 is set to zero degrees, the 2 nd suction recess 432 and the 2 nd suction recess 442 are disposed in the range of about 20 degrees to about 90 degrees in the counterclockwise rotation direction, and the 1 st suction recess 431 and the 1 st suction recess 441 are disposed in the range of about 200 degrees to about 270 degrees.

In addition, when viewed in the rotation axis direction, the 1 st discharge recess 433 and the 1 st discharge recess 443 are provided at the same position, and the 2 nd discharge recess 434 and the 2 nd discharge recess 444 are provided at the same position. In the case where the positive vertical axis in the drawing viewed in one direction shown in fig. 5 is set to zero degrees, the 2 nd discharge recess 434 and the 2 nd discharge recess 444 are provided in the range of about 130 degrees to about 175 degrees in the counterclockwise rotation direction, and the 1 st discharge recess 433 and the 1 st discharge recess 443 are provided in the range of about 310 degrees to about 355 degrees.

Further, the cam ring 40 is formed with 21 st discharge through holes 45, which are holes penetrating in the rotation axis direction so as to communicate the 1 st discharge recess 433 with the 1 st discharge recess 443. Further, 2 discharge through holes 46, which are holes penetrating in the rotation axis direction so as to communicate the 2 nd discharge recess 434 and the 2 nd discharge recess 444, are formed in the cam ring 40.

Further, the cam ring 40 is formed with a 1 st through hole 47 that penetrates in the rotation axis direction so as to communicate the inner end surface 43 between the 1 st suction recess 431 and the 2 nd discharge recess 434 with the outer end surface 44 between the 1 st suction recess 441 and the 2 nd discharge recess 444. Further, the cam ring 40 is formed with a 2 nd through hole 48 that is a hole penetrating in the rotational axis direction so as to communicate the inner end surface 43 between the 2 nd suction recess portion 432 and the 1 st discharge recess portion 433 with the outer end surface 44 between the 2 nd suction recess portion 442 and the 1 st discharge recess portion 443.

< Structure of inner plate 50 >

Fig. 7 is a view of the inner plate 50 viewed in one direction and the other direction of the rotation axis direction.

The inner plate 50 is a disk-shaped member having a through hole formed in the center thereof, and the inner plate 50 has an inner outer peripheral surface 51, an inner peripheral surface 52, an inner cam ring side end surface 53 as an end surface on the cam ring 40 side in the rotation axis direction, and an inner non-cam ring side end surface 54 as an end surface on the opposite side to the cam ring 40 side in the rotation axis direction.

As shown in fig. 7, the inner peripheral surface 51 has a circular shape when viewed in the rotation axis direction, and the distance from the inner peripheral surface 51 to the rotation center C is substantially the same as the distance from the cam ring peripheral surface 41 of the cam ring 40 to the rotation center C.

As shown in fig. 7, the inner peripheral surface 52 has a circular shape when viewed in the direction of the rotation axis, and the distance from the rotation center C to the inner peripheral surface 52 is substantially the same as the distance to the groove bottom of the spline 21 (see fig. 5) formed on the inner peripheral surface of the rotor 20.

An inner cam ring-side recess 530 formed of a plurality of recesses recessed from the inner cam ring-side end surface 53 and an inner non-cam ring-side recess 540 formed of a plurality of recesses recessed from the inner non-cam ring-side end surface 54 are formed in the inner plate 50.

The inner cam ring side concave part 530 has: a 1 st suction recess 531 formed at a position opposed to the 1 st suction recess 431 of the cam ring 40, and constituting a 1 st suction port 2; and a 2 nd suction recess 532 which is formed at a position opposed to the 2 nd suction recess 432 of the cam ring 40 and constitutes the 2 nd suction port 3. The 1 st suction recess 531 and the 2 nd suction recess 532 are formed point-symmetrically with respect to the rotation center C.

The 1 st suction recess 531 has a 1 st suction inner side portion 538 constituting a portion on the rotation center C side of the 1 st suction port 2. The 2 nd suction recess 532 has a 2 nd suction inner side portion 539 that constitutes a portion on the rotation center C side of the 2 nd suction port 3. These 1 st suction-inner side portion 538 and 2 nd suction-inner side portion 539 will be described in detail later.

In addition, the inner cam ring-side concave portion 530 has a 2 nd discharge concave portion 533 formed at a position opposed to the 2 nd discharge concave portion 434 of the cam ring 40.

The inner cam ring-side concave portion 530 has an inner 2 nd concave portion 534 at a position corresponding to the 2 nd suction concave portion 532 to the 2 nd discharge concave portion 533 in the circumferential direction and facing the cylindrical groove 232 of the vane groove 23 of the rotor 20 in the rotational radius direction.

The inner cam ring-side concave portion 530 has an inner 1 st concave portion 535 at a position corresponding to the 1 st discharge concave portion 433 in the circumferential direction and facing the cylindrical groove 232 of the vane groove 23 of the rotor 20 in the rotational radius direction.

The inner cam ring-side concave portion 530 includes a 1 st concave portion 536 formed at a position facing the 1 st through hole 47 of the cam ring 40 and a 2 nd concave portion 537 formed at a position facing the 2 nd through hole 48.

The inner non-cam ring side concave portion 540 includes an outer peripheral side groove 541 formed in the outer peripheral portion and serving as a groove into which the outer peripheral side O-ring 57 (see fig. 3) is fitted, and an inner peripheral side groove 542 formed in the inner peripheral portion and serving as a groove into which the inner peripheral side O-ring 58 (see fig. 3) is fitted. The outer peripheral side O-ring 57 and the inner peripheral side O-ring 58 seal a gap between the inner plate 50 and the housing 110.

Further, the inner plate 50 is formed with a 1 st discharge through hole 55, which is a hole penetrating in the rotation axis direction, at a position facing the 1 st discharge recess 443 of the cam ring 40. The opening portion of the 1 st discharge through hole 55 on the cam ring 40 side and the opening portion of the 2 nd discharge recess 533 are formed point-symmetrically with respect to the rotation center C.

Further, the inner plate 50 is formed with an inner 1 st through hole 56, which is a hole penetrating in the rotation axis direction, at a position corresponding to the 1 st suction recess 531 in the circumferential direction and facing the cylindrical groove 232 of the vane groove 23 of the rotor 20 in the rotation radius direction.

< Structure of outer plate 60 >

Fig. 8 is a view of the outer plate 60 viewed in the other direction and one direction of the rotation axis direction.

The outer plate 60 is a plate-like member having a substantially plate-like shape with a through hole formed in a central portion thereof, and the outer plate 60 has an outer peripheral surface 61, an outer inner peripheral surface 62, an outer cam ring side end surface 63 which is an end surface on the cam ring 40 side in the rotation axis direction, and an outer non-cam ring side end surface 64 which is an end surface on the opposite side to the cam ring 40 side in the rotation axis direction.

When viewed in the direction of the rotation axis, the outer peripheral surface 61 is shaped by cutting 2 portions from the circular shape of the base as shown in fig. 8. The distance of the circular shape of the base from the rotation center C is substantially the same as the distance of the cam ring outer peripheral surface 41 of the cam ring 40 from the rotation center C. The incisions at 2 sites had: a 1 st suction notch portion 611 formed at a position facing the 1 st suction recess portion 441 and constituting a 1 st suction port 2; and a 2 nd suction notch portion 612 formed at a position facing the 2 nd suction recess portion 442 and constituting the 2 nd suction port 3. The outer peripheral surface 61 is formed to be point-symmetrical with respect to the rotation center C, and the 1 st suction notch portion 611 and the 2 nd suction notch portion 612 are formed to be point-symmetrical with respect to the rotation center C.

As shown in fig. 8, the outer inner peripheral surface 62 has a circular shape when viewed in the direction of the rotation axis, and the distance from the outer inner peripheral surface 62 to the rotation center C is substantially the same as the distance to the groove bottom of the spline 21 formed in the inner peripheral surface of the rotor 20.

An outer cam ring side concave portion 630 made up of a plurality of concave portions recessed from the outer cam ring side end surface 63 is formed on the outer plate 60.

The outer cam ring-side recess 630 has a 1 st discharge recess 631, and the 1 st discharge recess 631 is formed at a position opposed to the 1 st discharge recess 443 of the cam ring 40.

The outer-cam-ring-side concave portion 630 has an outer-1 st concave portion 632 at a position corresponding to the 1 st suction notch portion 611 to the 1 st discharge concave portion 631 in the circumferential direction and facing the cylindrical groove 232 of the vane groove 23 of the rotor 20 in the rotational radius direction.

The outer-cam-ring-side concave portion 630 has an outer 2 nd concave portion 633 at a position corresponding to the 2 nd discharge concave portion 444 of the cam ring 40 in the circumferential direction and at a position facing the cylindrical groove 232 of the vane groove 23 of the rotor 20 in the rotational radius direction.

The cross section of the outer cam ring side concave portion 630 cut off by a plane parallel to the rotation axis direction and perpendicular to the outer peripheral surface 61 is V-shaped, and the outer cam ring side concave portion 630 has a first V groove 634 whose concave depth increases from the upstream side to the downstream side in the rotation direction. The downstream end of the first V groove 634 is connected to the upstream end of the 1 st discharge recess 631.

The cross section of the outer cam ring-side concave portion 630 cut off by a plane parallel to the rotation axis direction and perpendicular to the outer peripheral surface 61 is V-shaped, and the outer cam ring-side concave portion 630 has a second V groove 635 whose concave depth increases from the upstream side to the downstream side in the rotation direction. The downstream end of the second V-groove 635 is connected to the upstream end of the 2 nd discharge through hole 65.

Further, a 2 nd discharge through hole 65, which is a hole penetrating in the rotation axis direction, is formed in the outer plate 60 at a position facing the 2 nd discharge recess 444 of the cam ring 40. The opening portion of the 2 nd discharge through hole 65 on the cam ring 40 side and the opening portion of the 1 st discharge recess 631 are formed point-symmetrically with respect to the rotation center C.

Further, the outer plate 60 has an outer 2 nd through hole 66 formed therein at a position corresponding to the 2 nd suction notch portion 612 in the circumferential direction and facing the cylindrical groove 232 of the vane groove 23 of the rotor 20 in the rotational radial direction.

Further, in the outer plate 60, a 1 st through hole 67, which is a hole penetrating in the rotation axis direction, is formed at a position facing the 1 st through hole 47 of the cam ring 40, and a 2 nd through hole 68, which is a hole penetrating in the rotation axis direction, is formed at a position facing the 2 nd through hole 48 of the cam ring 40.

< Structure of housing 100 >

The housing 100 houses the rotor 20, the vanes 30, the cam ring 40, the inner plate 50, and the outer plate 60. The housing 100 accommodates one end of the rotary shaft 10 therein and projects the other end.

The housing 110 and the cover 120 are fastened by bolts.

(Structure of case 110)

Fig. 9 is a view of the housing 110 viewed in one direction of the rotation axis direction.

The housing 110 is a bottomed cylindrical member, and has a housing-side bearing 111 rotatably supporting one end of the rotary shaft 10 at the center of the bottom.

The housing 110 has an inner plate fitting portion 112 into which the inner plate 50 is fitted. The inner plate fitting portion 112 has an inner diameter side fitting portion 113 located at a position (inner diameter side) close to the rotation center C and an outer diameter side fitting portion 114 located at a position (outer diameter side) far from the rotation center C.

As shown in fig. 3, the inner diameter side fitting portion 113 is provided on the outer diameter side of the housing side bearing 111, and the inner diameter side fitting portion 113 includes: an inner diameter side cover portion 113a that covers a part of the inner peripheral surface 52 of the inner panel 50; and an inner diameter side restraining portion 113b that restrains the inner plate 50 from moving toward the bottom side. When viewed in the rotation axis direction, the inner diameter side cover portion 113a has a circular shape with a smaller distance from the rotation center C than the inner peripheral surface 52. The inner diameter-side restraining portion 113b is a ring-shaped surface perpendicular to the rotation axis direction, and has an inner circle having the same distance from the rotation center C as the inner diameter-side cover portion 113a, and an outer circle having a smaller distance from the rotation center C than the inner circumferential surface 52.

As shown in fig. 3, the outer diameter side fitting portion 114 includes: an outer diameter side cover portion 114a that covers a part of the inner outer peripheral surface 51 of the inner panel 50; and an outer diameter side restraining portion 114b that restrains the inner plate 50 from moving toward the bottom side. When viewed in the rotation axis direction, the outer diameter side shroud portion 114a has a circular shape having a distance from the rotation center C larger than a distance from the rotation center C of the inner outer peripheral surface 51. The outer diameter side suppression portion 114b is an annular surface perpendicular to the rotation axis direction, the distance from the rotation center C of the outer circle is the same as the distance from the rotation center C of the outer diameter side cover portion 114a, and the distance from the rotation center C of the inner circle is smaller than the distance from the rotation center C of the inner outer peripheral surface 51.

The inner plate 50 is inserted to the bottom side until the inner peripheral side O-ring 58 fitted in the inner peripheral side groove 542 of the inner plate 50 abuts against the inner diameter side restraining portion 113b, and the outer peripheral side O-ring 57 fitted in the outer peripheral side groove 541 abuts against the outer diameter side restraining portion 114 b. The inner peripheral side O-ring 58 contacts the inner peripheral side groove 542 of the inner plate 50, the inner peripheral side cover portion 113a and the inner peripheral side restraining portion 113b of the housing 110, and the outer peripheral side O-ring 57 contacts the outer peripheral side groove 541 of the inner plate 50, the outer peripheral side cover portion 114a and the outer peripheral side restraining portion 114b of the housing 110, whereby the housing 110 and the inner plate 50 are sealed. This defines a space S1 on the opening side of the inner panel fitting 112 and a space S2 on the bottom side of the inner panel fitting 112 in the case 110. The space S1 on the opening side of the inner plate fitting portion 112 constitutes an intake flow path R1 through which oil sucked from the 1 st intake port 2 and the 2 nd intake port 3 flows. The space S2 on the bottom side of the inner plate fitting portion 112 constitutes a 1 st discharge flow path R2 through which oil discharged from the 1 st discharge port 4 flows.

In addition, in the housing 110, in addition to a housing space for housing the rotor 20, the vane 30, the cam ring 40, the inner plate 50, and the outer plate 60, a housing outer side recess 115 recessed from the opening side in the rotation axis direction is formed at a position on the outer side in the rotation radius direction than the housing space. The casing outer concave portion 115 faces a cover outer concave portion 123 formed in the cover 120, which will be described later, and constitutes a casing 2 nd discharge flow path R3 through which oil discharged from the 2 nd discharge port 5 flows.

As shown in fig. 1, the casing 110 has a suction port 116 formed therein, and the suction port 116 communicates with the outside of the casing 110 through a space S1 on the opening side of the inner panel fitting portion 112. The suction port 116 is a cylindrical hole formed in the side wall of the housing 110, and includes a hole whose column direction is a direction perpendicular to the rotation axis direction. The suction port 116 constitutes a suction flow path R1 through which oil sucked from the 1 st suction port 2 and the 2 nd suction port 3 flows.

As shown in fig. 1, case 110 has first discharge port 117 formed therein, and first discharge port 117 communicates space S2 on the bottom side of inner plate fitting portion 112 with the outside of case 110. The 1 st discharge port 117 is a cylindrical hole formed in a side wall of the housing 110, and includes a hole whose column direction is a direction perpendicular to the rotation axis direction. The 1 st discharge port 117 constitutes a 1 st discharge flow path R2 through which oil discharged from the 1 st discharge port 4 flows.

As shown in fig. 1, a 2 nd discharge port 118 is formed in the housing 110, and the 2 nd discharge port 118 communicates the housing outside recess 115 with the outside of the housing 110. The 2 nd discharge port 118 is a cylindrical hole formed in the side wall of the housing outside recess 115 in the housing 110, and includes a hole having a columnar direction perpendicular to the rotation axis direction. The 2 nd discharge port 118 constitutes a casing 2 nd discharge flow path R3 through which oil discharged from the 2 nd discharge port 5 flows.

(Structure of cover 120)

As shown in fig. 2, the cover 120 has a cover-side bearing 121 that rotatably supports the rotary shaft 10 at a central portion.

The cover 120 has a cover 2 nd discharge recess 122 recessed in the rotation axis direction from the end surface on the case 110 side, formed at a position facing the 2 nd discharge through hole 65 and the outer 2 nd through hole 66 of the outer panel 60.

Further, the cover 120 is formed with a cover outer concave portion 123 and a cover concave portion connecting portion 124, the cover outer concave portion 123 being recessed in the rotation axis direction from the end surface on the housing 110 side at a position radially outward of the cover 2 nd discharge concave portion 122 in the rotation axis direction, and the cover concave portion connecting portion 124 connecting the cover 2 nd discharge concave portion 122 and the cover outer concave portion 123 at a position in the other direction in the rotation axis direction from the end surface on the housing 110 side. The cover outer concave portion 123 is formed to open at a position not facing the housing space formed in the housing 110, and the cover outer concave portion 123 faces the housing outer concave portion 115. The cover 2 nd discharge recess 122, the cover recess connecting portion 124, and the cover outer recess 123 constitute a cover 2 nd discharge flow path R4 (see fig. 4) through which the oil discharged from the 2 nd discharge port 5 flows. The oil discharged from the 2 nd discharge port 5 flows into the case 2 nd discharge flow path R3 through the cover concave portion connecting portion 124, and flows into the outer 2 nd through holes 66 through the cover 2 nd discharge concave portion 122.

Further, in the cover 120, a cover suction recess 125 recessed in the rotation axis direction from the end surface on the side of the housing 110 is formed at a portion facing the 1 st suction notch portion 611 and the 2 nd suction notch portion 612 of the outer panel 60 and a portion facing the space S1 on the opening side of the inner panel fitting portion 112 of the housing 110 and the space outside the cam ring outer peripheral surface 41 of the cam ring 40 in the rotation radius direction.

The cover suction recess 125 constitutes a suction flow path R1 through which oil sucked from the suction port 116 and sucked into the pump chamber from the 1 st suction port 2 and the 2 nd suction port 3 flows.

Further, the cover 120 is formed with a 1 st cover recess 127 and a 2 nd cover recess 128 recessed from the end surface on the side of the housing 110 in the rotation axis direction at positions facing the 1 st through hole 67 and the 2 nd through hole 68 of the outer panel 60, respectively.

< Effect of vane Pump 1 >

The vane pump 1 of the present embodiment has 10

vanes

30, and 10 vanes 30 are in contact with the cam ring inner circumferential surface 42 of the cam ring 40, thereby having 10 pump chambers, and the 10 pump chambers are formed by adjacent 2 vanes 30, the outer circumferential surface of the rotor 20 between these adjacent 2 vanes 30, the cam ring inner circumferential surface 42 between these adjacent 2 vanes 30, the inner cam ring side end surface 53 of the inner plate 50, and the outer cam ring side end surface 63 of the outer plate 60. When 1 pump chamber is looked at, the rotary shaft 10 rotates 1 rotation and the rotor 20 rotates 1 rotation, whereby the pump chamber rotates 1 rotation around the rotary shaft 10. During 1 rotation of the pump chamber, oil sucked from the 1 st suction port 2 is compressed to increase pressure and discharged from the 1 st discharge port 4, and oil sucked from the 2 nd suction port 3 is compressed to increase pressure and discharged from the 2 nd discharge port 5.

< about the starting point Angle >

Hereinafter, a rotational angle (hereinafter, referred to as a "starting point angle") at which the distance L from the rotation center C of the cam ring inner peripheral surface 42 of the cam ring 40 starts to increase will be described. The starting point angle is a rotation angle at which the distance L starts to increase after a predetermined rotation angle has elapsed in the section in which the distance L is the smallest. The predetermined rotation angle is, for example, 9 degrees. When the predetermined rotation angle is 9 degrees, the ratio of the predetermined rotation angle to the rotation angle between 2 vanes 30 constituting the pump chamber (inter-vane rotation angle) is 9/(360/10) to 0.25. Further, the ratio of the predetermined rotation angle to the inter-blade rotation angle may be 0.11 or more. The interval of the predetermined rotation angle at which the distance L is the smallest and the starting point angle are provided between the discharge port and the suction port.

Here, the 1 st suction port 2 is constituted by the 1 st suction recess 431 and the 1 st suction recess 441 formed in the cam ring 40, the 1 st suction recess 531 formed in the inner plate 50, and the 1 st suction notch 611 formed in the outer plate 60.

The 2 nd suction port 3 is constituted by the 2 nd suction recess 432 and the 2 nd suction recess 442 formed in the cam ring 40, the 2 nd suction recess 532 formed in the inner plate 50, and the 2 nd suction notch portion 612 formed in the outer plate 60.

The 1 st discharge port 4 is constituted by the 1 st discharge recess 433 and the 1 st discharge recess 443 formed in the cam ring 40, the 1 st discharge through hole 55 formed in the inner plate 50, and the 1 st discharge recess 631 formed in the outer plate 60.

The 2 nd discharge port 5 is constituted by the 2 nd discharge recess 434 and the 2 nd discharge recess 444 formed in the cam ring 40, the 2 nd discharge recess 533 formed in the inner plate 50, and the 2 nd discharge through hole 65 formed in the outer plate 60.

In the following description, when there is no need to distinguish between the 1 st suction port 2 and the 2 nd suction port 3, the 1 st suction port 2 and the 2 nd suction port 3 may be collectively referred to as "suction ports". In addition, when it is not necessary to distinguish between the 1 st discharge port 4 and the 2 nd discharge port 5, the 1 st discharge port 4 and the 2 nd discharge port 5 may be collectively referred to as "discharge ports".

The vane pump 1 of the above embodiment includes: a rotor 20 that rotatably supports 10 blades 30 so as to be movable in a rotation radius direction; and a cam ring 40 having an inner circumferential surface facing the outer circumferential surface of the rotor 20, the capacity of the pump chamber changing in accordance with the rotation of the rotor 20. The volume of the pump chamber changes, and the pump chamber moves at least to the suction step and the discharge step.

The suction step is a step of sucking oil through the suction port. The suction process section is a section in which oil is sucked through the suction port. The discharge step is a step of discharging the oil through the discharge port. The discharge step section is a section in which oil is discharged through the discharge port.

Hereinafter, the rotation angle at which the discharge step ends and the rotation angle at which the suction step starts will be described.

In the following description, the upstream vane 30 among the 2 vanes 30 constituting the pump chamber is referred to as an upstream vane, and the downstream vane 30 is referred to as a downstream vane.

The rotation angle at which the discharge process is completed is the rotation angle at which the upstream blade passes through the downstream end of the discharge port (hereinafter, also referred to as "downstream end"). The upstream vane passes through the downstream end of the discharge port, and discharges oil into the pump chamber without passing through the discharge port.

The rotation angle at which the suction process starts is the rotation angle at which the downstream vane passes through the upstream end of the suction port (hereinafter, also referred to as "upstream end"). The downstream-side vane passes through an upstream end of the suction port, thereby sucking oil from the pump chamber via the suction port.

Fig. 10 is a view of the cam ring 40 and the inner plate 50 viewed in one direction.

Fig. 11 is a view of the cam ring 40 and the outer plate 60 viewed in another direction.

Hereinafter, the rotation angle at which the discharge step ends and the rotation angle at which the suction step starts will be described. Since the 1 st side and the 2 nd side are point-symmetric, the 1 st side will be described in detail below, and the 2 nd side will not be described in detail.

Since the rotation angles of the downstream ends of the 1 st discharge recess 433 and the 1 st discharge recess 443 formed in the cam ring 40, the 1 st discharge through hole 55 formed in the inner plate 50, and the 1 st discharge recess 631 formed in the outer plate 60, which constitute the 1 st discharge port 4, are all the same, the rotation angle of the end portion (downstream end) on the downstream side of the 1 st discharge port 4 becomes the rotation angle of the downstream end of these portions. For example, as the downstream end of the cam ring 40, there is a downstream end formed in the 1 st exhaust recess 433(443) of the cam ring 40 shown in fig. 10 and 11, that is, a 1 st exhaust recess downstream end 433f (443 f). The downstream end of the inner plate 50 is, for example, a 1 st discharge through hole downstream end 55f which is a downstream end of the 1 st discharge through hole 55 formed in the inner plate 50 shown in fig. 10. The downstream end of the outer plate 60 is a 1 st discharge recess downstream end 631f which is a downstream end of the 1 st discharge recess 631 formed in the outer plate 60 shown in fig. 11.

Since the rotation angles of the downstream ends of the 2 nd discharge recess 434 and the 2 nd discharge recess 444 formed in the cam ring 40, the 2 nd discharge recess 533 formed in the inner plate 50, and the 2 nd discharge through hole 65 formed in the outer plate 60, which constitute the 2 nd discharge port 5, are all the same, the rotation angle of the end portion (downstream end) on the downstream side of the 2 nd discharge port 5 becomes the rotation angle of the downstream end of these portions. For example, as the downstream end of the cam ring 40, a downstream end formed in the 2 nd exhaust recess 434(444) of the cam ring 40 as shown in fig. 10 and 11, that is, the 2 nd exhaust recess downstream end 434f (444 f). The downstream end of the inner plate 50 is, for example, a 2 nd discharge recess upstream end 533f which is a downstream end formed in the 2 nd discharge recess 533 of the inner plate 50 shown in fig. 10. The downstream end of the outer plate 60 is a 2 nd discharge through hole 65f which is a downstream end of the 2 nd discharge through holes 65 formed in the outer plate 60 shown in fig. 11.

Since the rotation angles of the upstream ends of the 1 st suction recess 431 and the 1 st suction recess 441 formed in the cam ring 40, the 1 st suction recess 531 formed in the inner plate 50, and the 1 st suction notch 611 formed in the outer plate 60, which constitute the 1 st suction port 2, are all the same, the rotation angle of the upstream end of the 1 st suction port 2 becomes the rotation angle of the upstream end of these portions. For example, as the upstream end of the cam ring 40, there is a 1 st suction recess upstream end 431e (441e) which is an upstream end formed in a 1 st suction recess 431(441) of the cam ring 40 shown in fig. 10 and 11. The upstream end of the inner plate 50 is, for example, a 1 st suction recess upstream end 531e which is an upstream end formed in the 1 st suction recess 531 of the inner plate 50 shown in fig. 10. The upstream end of the outer panel 60 is a 1 st suction-notch upstream end 611e which is an upstream end of the 1 st suction-notch portion 611 formed in the outer panel 60 shown in fig. 11.

Since the rotation angles of the upstream ends of the 2 nd suction recess 432 and the 2 nd suction recess 442 formed in the cam ring 40, the 2 nd suction recess 532 formed in the inner plate 50, and the 2 nd suction notch portion 612 formed in the outer plate 60 constituting the 2 nd suction port 3 are all the same, the rotation angle of the upstream end of the 2 nd suction port 3 becomes the rotation angle of the upstream end of these portions. For example, as the upstream end of the cam ring 40, for example, an upstream end formed in the 2 nd suction recess 432(442) of the cam ring 40 shown in fig. 10 and 11, that is, a 2 nd suction recess upstream end 432e (442e) is exemplified. The upstream end of the inner plate 50 is, for example, a 2 nd suction recess upstream end 532e which is an upstream end formed in the 2 nd suction recess 532 of the inner plate 50 shown in fig. 10. The upstream end of the outer plate 60 is a 2 nd suction slit portion downstream end 612e which is an upstream end of the 2 nd suction slit portion 612 formed in the outer plate 60 shown in fig. 11.

Here, the rotation angle between the suction port and the discharge port is generally substantially the same as the rotation angle of the adjacent 2 vanes, and for example, in the case of a vane pump device of 10-vane specification, the rotation angle of the adjacent 2 vanes 30 is 36 degrees (360 degrees/10 degrees is 36 degrees), and the angle between the suction port and the discharge port is also substantially 36 degrees.

Further, the vane pump device of the 10-vane specification will be described in detail.

Generally, a vane pump device has: a rotor that rotatably supports a plurality of blades so as to be movable in a rotation radius direction; and a cam ring having an inner circumferential surface facing the outer circumferential surface of the rotor, wherein a distance from a rotation center of the rotor to the inner circumferential surface of the cam ring changes according to a rotation angle of the rotor, and a volume of a pump chamber defined by the outer circumferential surface of the rotor, the inner circumferential surface of the cam ring, and adjacent 2 vanes of the plurality of vanes changes according to the rotation angle.

Further, the capacity of the pump chamber is minimized when 2 adjacent vanes are overlapped between the suction port and the discharge port, which are the smallest distance from the inner peripheral surface of the cam ring (for example, fig. 5 shows a state where 2 adjacent vanes are overlapped between the suction port and the discharge port, the upstream side vane 31 is located at the end portion on the downstream side in the discharge port, and the downstream side vane 32 is located at the end portion on the upstream side in the suction port).

After the predetermined rotation angle has passed in the section with the smallest distance, the start angle, which is the rotation angle at which the distance starts to increase, coincides with the suction port start point (rotation angle at which the suction process starts), and from the rotation angle with the largest distance, the rotation angle with the smallest distance coincides with the discharge port end point (rotation angle at which the discharge process ends).

In the vane pump device, the volume of the pump chamber at the start of suction is the smallest, and the volume of the pump chamber increases by rotating from this position. When the upstream vanes of the 2 vanes are aligned with the downstream side of the suction port, the distance from the pump chamber to the inner peripheral surface of the cam ring becomes maximum, and the capacity also becomes maximum. Thereafter, the distance to the inner peripheral surface of the cam ring is decreased, and when 2 adjacent vanes are overlapped between the suction port and the discharge port having the smallest distance to the inner peripheral surface of the cam ring, the process of minimizing the volume is repeated.

In the vane pump device, the discharge flow rate is reduced, whereby the apparent performance of the pump is degraded. In order to avoid a decrease in pump performance, the starting point angle has not been shifted upstream in the rotation direction. However, the inventors have conducted studies and found that a vane pump device capable of reducing the pressure in the pump chamber at the start of the suction process can be provided by offsetting the starting point angle upstream in the rotation direction from the conventional one. The present invention has been completed based on such findings.

In the vane pump 1 of the present embodiment, the starting point angle is set to a range from a position on the upstream side in the rotation direction and having a rotation angle difference of 2.5 degrees from the center angle (see fig. 13) to a position on the downstream side in the rotation direction and having a rotation angle difference of 2.5 degrees from the center angle between the rotation angle of the downstream end (downstream end) forming the discharge port and the rotation angle of the center of the upstream end (upstream end) forming the suction port. In other words, when an angle obtained by equally dividing the rotation angle of the downstream-side end portion forming the discharge port and the rotation angle of the upstream-side end portion forming the suction port is set as the center angle, the start point angle is set so that the rotation angle difference from the center angle is 2.5 degrees or less. This is based on the following reason.

Fig. 12 is a view showing a part of the cam ring inner peripheral surface 42 having a different starting point angle. Fig. 12 is an enlarged view of the XII portion of fig. 6.

Fig. 13 is a simulation result showing the discharge flow rate ratio at different starting point angles.

The configuration in which the rotation angle difference between the starting point angle and the center angle was 12.5 degrees on the downstream side in the rotation direction was set as a comparative configuration, and the discharge flow rates of the 4 types of configurations a to D having different starting point angles were compared with the discharge flow rate of the comparative configuration. In configuration a, the rotation angle difference between the start angle and the center angle is 2.5 degrees on the upstream side in the rotation direction. In configuration B, the rotation angle difference between the start angle and the center angle is 1.25 degrees on the upstream side in the rotation direction. In configuration C, the rotation angle difference between the start angle and the center angle is zero degrees (0 degrees), that is, the start angle and the center angle are the same. In configuration D, the rotation angle difference between the starting point angle and the center angle is 2.5 degrees on the downstream side in the rotation direction. If the rotation angle of the center angle is set to 0 degrees, the direction on the downstream side of the rotation direction is set to positive, and the direction on the upstream side of the rotation direction is set to negative, the starting point angles of the structure A, B, C, D and the comparative structure are-2.5 degrees, -1.25 degrees, 0 degrees, 2.5 degrees, and 12.5 degrees, respectively. In the configurations a to D and the comparative configuration, the highest point of the convex portion drawn by the distance L for each rotation angle and the rotation angle that becomes the highest point are made the same, and the starting point angles are made different. Therefore, in the process from the starting point angle to the rotation angle at the highest point, the amount of change in the distance L per unit rotation angle (the inclination angle of the distance L in fig. 6) becomes smaller in the order of the structure A, B, C, D and the comparative structure.

The discharge flow rate is the volume of oil discharged from the 1 st drain 117 and the 2 nd drain 118 in 1 minute, and is expressed in L/min.

As shown in fig. 13, the discharge flow rate of structure a was 1.17 times the discharge flow rate of the comparative structure, the discharge flow rate of structure B was 1.18 times the discharge flow rate of the comparative structure, the discharge flow rate of structure C was 1.19 times the discharge flow rate of the comparative structure, and the discharge flow rate of structure D was 1.15 times the discharge flow rate of the comparative structure.

As shown in fig. 13, by setting the starting point angle to the upstream side in the rotation direction from the starting point angle of the comparison structure, the discharge flow rate becomes larger than that of the comparison structure. This is based on the following reason.

In the discharge step, if the high-pressure oil is not completely discharged and the discharge step is completed, the pressure in the pump chamber is maintained high even though the discharge step is completed. At the start of the suction process, if the pressure of the pump chamber is higher than the pressure of the suction port, the oil in the pump chamber flows backward to the suction port. Even if the first V groove 634 or the second V groove 635 is formed, a reverse flow may be generated. When the reverse flow occurs, the suction port communicates with the pump chamber, and the oil is not immediately sucked into the pump chamber from the suction port, and there is a possibility that the start of suction into the pump chamber is delayed. If the start of oil suction into the pump chamber is delayed, the volume of oil sucked into the pump chamber in the suction process is reduced. As the volume of the sucked oil decreases, the discharge flow rate also decreases. As a result, the pump efficiency is reduced. When the reverse flow occurs, there is a possibility that a sound generated at the time of the reverse flow or a sound of bubbles (air) contained in the oil being broken along with the reverse flow is generated.

Fig. 14 is a diagram showing a part of the change in the volume V of the pump chamber at different starting point angles.

Here, the rotation angle of the upstream vane among the 2 vanes 30 constituting the pump chamber is defined as the rotation angle of the pump chamber, and the volume V of the pump chamber including the upstream vane is defined as the volume V at the rotation angle. That is, when the rotation angle of the upstream vane is zero degrees (when the center of the upstream vane in the rotation direction is located on the positive vertical axis in the figure viewed in one direction shown in fig. 5), the volume V of the pump chamber configured to include the upstream vane is set to the volume V at the rotation angle of zero degrees. Since the blade 30 has a thickness in the rotational direction, the rotational angle of the blade 30 is based on the center in the rotational direction.

As shown in fig. 14, in the comparative structure, the volume V is the smallest when the difference in rotation angle from the center angle is approximately 19 degrees on the upstream side in the rotation direction. In the configuration a, the volume V is the smallest when the difference in rotation angle from the center angle is approximately 30 degrees on the upstream side in the rotation direction. In the configuration B, the volume V is the smallest when the difference in rotation angle from the center angle is approximately 29 degrees on the upstream side in the rotation direction. In the configuration C, the volume V is the smallest when the difference in rotation angle from the center angle is approximately 27.5 degrees on the upstream side in the rotation direction. In the configuration D, the volume V is the smallest when the difference in rotation angle from the center angle is approximately 25 degrees on the upstream side in the rotation direction.

That is, in the configurations a to D and the comparative configuration, the distance L gradually decreases from the upstream side toward the downstream side in the rotational direction at the section where the distance L is smallest, and gradually increases from the upstream side toward the downstream side in the rotational direction at the section where the angle is smaller. In addition, when the downstream-side vane is present in a section where the distance L is the smallest and the upstream-side vane is present in a section where the distance L is gradually smaller, the volume V of the pump chamber becomes smaller as it goes from the upstream side toward the downstream side in the rotational direction, and then the downstream-side vane is moved to a section where the distance L is gradually larger, whereby the volume V of the pump chamber becomes larger even when the upstream-side vane is in a section where the distance L is gradually smaller.

The starting point angle of the vane pump 1 of the present embodiment is located on the upstream side in the rotation direction from the starting point angle of the comparative structure, and the distance L of the present embodiment is larger than the distance L of the comparative structure when the rotation angles are the same between the rotation angle of the downstream end of the discharge port and the rotation angle of the upstream end of the suction port. Therefore, between the rotation angle of the downstream end of the discharge port and the rotation angle of the upstream end of the suction port, the volume V of the pump chamber of the present embodiment is larger than the volume V of the pump chamber of the comparative structure in the case where the rotation angles are the same. Therefore, the vane pump 1 of the present embodiment is lower in pressure of the pump chamber at the rotation angle at which the suction process starts than the vane pump of the comparative structure. As a result, at the rotation angle at which the suction process starts, the oil does not easily flow backward from the pump chamber to the suction port, and the start of oil suction into the pump chamber is not easily delayed. Therefore, the volume of the oil sucked into the pump chamber in the suction process is not easily reduced. That is, the volume of the oil sucked into the pump chamber in the suction process of the vane pump 1 of the present embodiment is larger than the volume of the oil sucked into the pump chamber in the suction process of the vane pump of the comparative structure. Further, when the volume of the oil sucked in increases, the discharge flow rate also increases. As a result, the pump efficiency is increased.

As shown in fig. 13, the discharge flow rate is the largest in the configuration C in which the rotation angle difference between the starting point angle and the center angle is zero degrees, that is, the starting point angle is the same as the center angle, and the discharge flow rate gradually decreases as the starting point angle moves away from the center angle. Therefore, it is most preferable that the starting point angle is the same as the central angle.

However, as shown in fig. 13, even if the starting point angle is separated from the center angle by 2.5 degrees, for example, the discharge flow rate of the structure a on the upstream side in the rotation direction from the center angle is 1.17 times the discharge flow rate of the comparative structure, and the discharge flow rate of the structure D on the downstream side in the rotation direction from the center angle is 1.15 times the discharge flow rate of the comparative structure. Therefore, when the starting point angle is in the range from the position on the upstream side of the center angle in the rotation direction and at which the rotation angle difference is 2.5 degrees to the position on the downstream side of the center angle in the rotation direction and at which the rotation angle difference is 2.5 degrees, the discharge flow rate becomes 1.15 times or more the discharge flow rate of the comparative structure. Thus, the starting point angle may also be 2.5 degrees apart from the central angle.

On the other hand, if the starting point angle is too far from the center angle at a position on the upstream side in the rotation direction than the center angle, in other words, if the starting point angle is too close to the rotation angle of the downstream end of the discharge port, the pump capacity decreases. The pump capacity is a capacity of oil that can be sucked and discharged during 1 rotation in 1 pump chamber, and is represented by cc/rev.

As shown in fig. 15, the pump capacity of configuration a was 1.00 times the pump capacity of the comparative configuration, and the pump capacity of configuration B was 1.005 times the pump capacity of the comparative configuration. The pump capacity of structure C is 1.006 times the pump capacity of the comparative structure, and the pump capacity of structure D is 1.009 times the pump capacity of the comparative structure. Therefore, if the starting point angle is further away from the center angle by 2.5 degrees on the upstream side in the rotation direction (configuration a), the pump capacity is considered to be smaller than that of the comparative configuration. This is for the following reason.

The discharge process ends at the rotation angle at which the upstream vane passes the downstream end of the discharge port, but the volume V of the pump chamber starts to increase at the rotation angle earlier before the discharge process ends, the more the starting point angle is located on the upstream side in the rotation direction. Therefore, the rotation angle of the pump chamber becomes smaller as the starting point angle is located on the upstream side in the rotation direction before the end of the discharge process, and therefore, the oil to be discharged in the discharge process is difficult to be discharged from the discharge port. As a result, the pump capacity decreases as the starting point angle is located on the upstream side in the rotation direction. Therefore, it is considered that if the rotation angle difference between the start angle and the center angle is greater than 2.5 degrees at the upstream side in the rotation direction from the center angle, the discharge flow rate becomes smaller than that of the comparative structure.

From the above, when the starting angle is located upstream in the rotation direction from the center angle, the rotation angle difference is preferably 2.5 degrees or less.

The vane pump 1 of the present embodiment is a pump having 10 vanes 30. The ratio of the difference in rotation angle of 2.5 degrees to the rotation angle between 2 vanes 30 constituting the pump chamber (hereinafter, also referred to as "inter-vane rotation angle") was 2.5/(360/10) which was 0.07.

Therefore, the vane pump 1 of the present embodiment is characterized in that the rotation angle difference is set to 0.07 × (360/10 (number of vanes)) degrees or less when the starting point angle is on the upstream side in the rotation direction from the center angle.

< modification example 1 >

The vane pump 1 according to modification 1 is characterized in that the discharge-side rotational angle difference between the starting angle and the rotational angle of the downstream end of the discharge port is equal to or less than the suction-side rotational angle difference between the starting angle and the rotational angle of the downstream end of the suction port. In other words, the vane pump 1 according to modification 1 is characterized in that the starting point angle is equal to or more upstream in the rotation direction than the center angle that is the center of the rotation angle of the downstream end of the discharge port and the rotation angle of the downstream end of the suction port.

However, the starting point angle may be located upstream of the center angle in the rotation direction and downstream of the center angle by a difference of 2.5 degrees in rotation angle. Since the ratio of the rotation angle difference 2.5 degrees to the inter-blade rotation angle is 0.07, the starting point angle may be located on the upstream side in the rotation direction from the center angle and on the downstream side in the rotation direction from the position where the ratio to the inter-blade rotation angle is 0.07.

As shown in fig. 13, if the rotation angle of the center angle is 0 degrees and the direction on the upstream side in the rotation direction is negative, the discharge flow rate of the structure A, B, C having the starting point angles of-2.5 degrees, -1.25 degrees, and 0 degrees is 1.17 times or more the discharge flow rate of the comparative structure. Therefore, by setting the discharge-side rotation angle difference between the starting angle and the rotation angle of the downstream end of the discharge port to be equal to or smaller than the suction-side rotation angle difference between the starting angle and the rotation angle of the downstream end of the suction port, the pump efficiency can be improved as compared with the comparative structure. In addition, the sound generated by the reverse flow can be suppressed.

< 2 nd modification example >

In the above embodiment, the maximum point of the convex portion drawn by the distance L for each rotation angle and the rotation angle at the maximum point are made the same, the starting point angle is made different, and the amount of change in the distance L per unit rotation angle in the process from the starting point angle to the rotation angle at the maximum point is made different. For example, the amount of change in the distance L per unit rotation angle (the inclination angle of the distance L in fig. 6) from the start angle to the rotation angle at the highest point is reduced in the order of the configuration A, B, C, D and the comparative configuration (see fig. 12). However, the vane pump 1 of the embodiment is not particularly limited to this embodiment as long as the capacity of the pump chamber starts to increase earlier than the capacity of the pump chamber of the comparative structure.

Fig. 16 is a view showing a part of the cam ring inner peripheral surface 42 of the 2 nd modification.

As shown in fig. 16, the radius of curvature R of the base end portion may be increased so that, of the rotation angles between the highest point of the convex portion described by the distance L and the starting point angle, the rotation angle side at the highest point is, for example, about 8, which is the same as the comparative structure, and the distance L of the cam ring inner peripheral surface 42 of the 2 nd modification may be larger than the distance L of the comparative structure at a rotation angle of about 2 on the starting point angle side. In this configuration, the volume of the pump chamber can be started to be increased earlier than in the comparative configuration, and the pump efficiency can be improved and the noise caused by the reverse flow can be suppressed as compared with the comparative configuration.

Fig. 16 illustrates a case where the starting point angle is the same as the center angle. The radius of curvature R may be increased as the starting point angle is located on the upstream side in the rotation direction.

Description of the reference symbols

1: a vane pump; 2: 1 st suction port; 3: a 2 nd suction port; 4: 1 st discharge port; 5: a 2 nd discharge port; 10: a rotating shaft; 20: a rotor; 30: a blade; 40: a cam ring; 50: an inner plate; 60: an outer plate; 100: a housing; 110: a housing; 120: and (4) a cover.

Claims

1. A vane pump device having:

a rotor which rotatably supports 10 blades so as to be movable in a rotation radius direction; and

a cam ring having an inner circumferential surface opposed to the outer circumferential surface of the rotor,

by changing the distance from the rotation center of the rotor to the inner peripheral surface of the cam ring in accordance with the rotation angle of the rotor, so that the volumes of pump chambers divided by the outer peripheral surface of the rotor, the inner peripheral surface of the cam ring, and adjacent 2 vanes of the plurality of vanes are changed according to the rotation angle, thereby, at least to the suction process of sucking the working fluid into the pump chamber and the discharge process of discharging the working fluid from the pump chamber, when an angle at which the rotation angle forming the downstream-side end portion in the discharge port and the rotation angle forming the upstream-side end portion in the suction port are equally divided is set as a central angle, after a predetermined rotation angle has elapsed in the interval in which the distance is the same, the rotation angle difference between the start angle, which is the rotation angle at which the distance starts to increase, and the center angle is 2.5 degrees or less.

2. The vane pump device according to claim 1,

the starting point angle is located upstream of the center angle, and the rotation angle difference is 0 degrees or more and 2.5 degrees or less.

3. The vane pump device according to claim 2,

the rotation angle difference is 0 degree.