WO2005005837A1

WO2005005837A1 - Vane pump

Info

Publication number: WO2005005837A1
Application number: PCT/JP2003/008724
Authority: WO
Inventors: Tetsuya Ishii; Masaaki Busujima; Takaki Habiro; Shigeji Kunimoto
Original assignee: Unisia Jkc Steering Systems Co., Ltd.
Priority date: 2003-07-09
Filing date: 2003-07-09
Publication date: 2005-01-20
Also published as: CN100425837C; JPWO2005005837A1; CN1764783A

Abstract

A vane pump has a side plate provided at the side of a cam ring and having discharge ports (21, 34) opened in it; a rotor rotatably received in the cam ring and rotated by a drive shaft; and vanes projectably held, in a circumferential direction of the cam ring, in slots formed in radial directions in the outer periphery of the rotor. Fine grooves (40, 40) communicating with the discharge ports are formed in the inside face sliding on the rotor of the side plate, and the fine grooves are formed so as to start from the discharge ports and to be gradually reduced in width in a opposite direction to the rotational direction of the rotor. Tip portions (40b, 40b) of the fine grooves are formed so that they are directed toward more inward than a rotational locus line (X) of each of the vanes which locus line passes through base end portions (40a, 40a) of the fine grooves.

Description

Vane pump

Technical field

The present invention relates to a vane pump used as a hydraulic power supply of power steering of a vehicle or the like. Background art

Various types of vane pumps used in vehicles of this type have been conventionally provided, and one of them is known from Japanese Patent Application Laid-Open No. 10-8626 issued by the Japan Patent Office. It is done.

In this vane pump, a pump rotor includes a force mulling, a side plate is accommodated on the side of the cam ring, and a vane rotor forming a pressure chamber between the cam ring and the cam ring. It is provided rotatably.

On the outer periphery of the vane rotor, a plurality of slots are formed along the radial direction at substantially equally spaced positions in the circumferential direction, and in each of the slots, the vanes are respectively at the inner periphery of the cam ring. It is held freely in the surface direction.

Further, the side plate has a discharge port formed on one end face on the side of the vane loop, and a whisker groove whose base end opens to the hole edge of the discharge port is in the direction opposite to the rotation direction of the vane rotor. The whisker-like groove is formed to have a curve whose opening area changes smoothly as it goes to the discharge port.

The vane loop is connected to one end of a drive shaft threaded into the pump housing. The drive shaft is adapted to transmit rotational force from the crankshaft of the engine via a driven pulley mounted on the other end side by a timing belt. ' Then, when the vane rotor rotates with the rotational drive of the drive shaft, each vane is protruded from the slot due to the pressure of the back pressure chamber, and the tip end of each vane rotates while being in sliding contact with the inner circumferential surface of the cam ring. . As a result, the working fluid flowing into the pump chamber between the vanes from the suction port formed in the pump housing is compressed by the vanes and discharged to the discharge port for pumping action. Is to be implemented.

Also, when the pump chamber communicates with the discharge port, a so-called whisker-like groove is formed to prevent the high pressure of the discharge port from rapidly flowing into the pump chamber, and the whisker-like groove smoothly rises to operate. Control is performed so that fluid pressure does not change rapidly at the discharge port, and hydraulic pressure pulsations are reduced.

However, in the above-described conventional vane pump, although each whisker groove formed in the side plate is formed by a curve which smoothly changes toward the discharge port, It is directed radially outward of the side.

Therefore, when one vane is rotationally moved to the tip of the whisker groove with the rotation of the vane rotor and the pressure in the discharge port becomes high, the high pressure working fluid flows back in the whisker groove. Then, it abuts from the tip to the vicinity of the radial outer end of the next side of the adjacent vane. Therefore, a load in the direction opposite to the rotational direction acts on this vane, and a resistance load in the reverse direction is applied to the vane rotor. As a result, the pump efficiency may be reduced.

In addition, due to the load in the direction opposite to the direction of rotation of the vane, an excessive stress is applied to the slot of the vane rotor, and the slot may be deformed.

Disclosure of the invention

The present invention has been made in view of the above-mentioned conventional technical problems, and the invention according to claim 1 comprises: a cam ring housed and disposed in a pump housing; and a cam ring disposed on a side of the cam ring A side plate having a discharge port formed therein; and the cam ring A rotor rotatably accommodated in the interior and rotationally driven by the drive shaft, and a plurality of slots formed along the radial direction at the outer peripheral portion of the rotor are retractable in the direction of the inner peripheral surface of the cam ring A vane pump comprising: a vane held; and a whisker groove cut out substantially along a circumferential direction on an inner surface of the side plate on the rotor side, the whisker groove communicating with the discharge port. From the discharge port, along the direction opposite to the direction of rotation of the rotor, it is formed to be gradually tapered, and the end of the whisker is a rotation locus passing through the base of the whisker of each vane. It is characterized in that it is formed to be more inward than it is.

According to the present invention, when one vane passes through the end of the beard groove with the rotation of the vane loop, the high-pressure working fluid, which flows back from the discharge port into the inside of the beard groove, is a part of the beard groove. The tip end, that is, from the tip directed inward, abuts on the radially inner end side of the side face of the next vane adjacent to the tip end. For this reason, the load (moment) force in the direction opposite to the rotational direction with respect to the vane is sufficiently reduced, and the force in the reverse direction to the vane rotor is also significantly reduced. As a result, it is possible to suppress a decrease in pump efficiency. According to the invention of claim 2, the extension line of the tip of the whisker groove is oriented substantially toward the base of the radial length of the side surface of the vane which is rotationally moved near the whisker groove as the rotor rotates. It is characterized by

According to the present invention, as described above, since the working flow backflowing the whisker from the discharge port is made to abut the base side of the inner end of the side of the adjacent vane, the opposite direction to the vane It is possible to further reduce the load on

The invention according to claim 3 is characterized in that the tip end portion of the whisker groove is formed to extend in the direction of the vane rotationally moved in the vicinity of the whisker groove along with the rotation of the spout. Therefore, according to the present invention, by forming the tip end of the whisker groove, the directivity of the side surface of the adjacent vane in the radial direction toward the inner end becomes stronger, and a high pressure working fluid can be obtained. It becomes possible to guide more reliably toward the inner end of one side.

Also, due to the extension of the whiskers, for example, especially when driving straight ahead of the vehicle

-Reduce the change in discharge hydraulic pressure when not rotating Can be That is, when the steering wheel is not largely rotated, the differential pressure between the discharge port and the pump chamber between the pair of vanes rotationally moved in the vicinity is small. The start point of communication with the discharge port is quickened by the whisker groove in which the pump chamber which is rotationally moved near the discharge port with the rotation of the rotor is extended, and the pump chamber and the pump chamber are rotated. The communication time with the discharge port becomes longer. Therefore, since the transfer time of the working fluid in the discharge port to the pump chamber becomes longer, the change in pressure (hydraulic pressure) of the working fluid in the discharge port becomes smaller.

As a result, even when the steering wheel is slightly rotated, it is possible to reduce the pulsation of the hydraulic pressure in the discharge port. Brief description of the drawings

FIG. 1 is a longitudinal sectional view showing a vane pump according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1 of FIG.

FIG. 3 is a front view of a belt loop and a cam ring provided in the present embodiment. FIG. 4 is a cross-sectional view taken along the line B-B in FIG.

FIG. 5 is a front view of the side plate viewed from the direction of arrows C and C in FIG.

FIG. 6 is a longitudinal sectional view of a whisker groove.

FIG. 7 is a D arrow view of FIG. 6 showing a whisker groove.

FIG. 8 is a rear view of the side plate.

FIG. 9 is a cross-sectional view taken along line E-E of FIG.

FIG. 10 is a longitudinal sectional view of a vane pump showing another example.

FIG. 11 is a front view of the rear plate viewed from the arrow F-F direction of FIG. FIG. 12 is a cross-sectional view taken along line G-G of FIG.

FIG. 13 is an enlarged view of arrow H in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a vane pump concerning the present invention is explained in full detail based on a drawing. This vane pump is applied to a pump as a supply source for supplying hydraulic pressure to hydraulic equipment such as a power steering device of a vehicle, as in the prior art, and as shown in FIG. It is mainly composed of a fixed pump housing 1, a pump body 2 disposed in the pump housing 1, and a drive shaft 3 having one end portion passing through the inside of the pump housing 1. The pump housing 1, as shown in FIGS. 1 and 2, comprises a block-shaped pump body 6 having a suction passage 4 and a discharge passage 5, and a pump cover 7 connected to the pump body 6. A space for accommodating the pump body 2 is provided between the pump body 6 and the pump cover 7.

As shown in FIGS. 1 to 4, the pump body 2 includes a cam ring 8 housed and disposed inside the pump cover 7, a vane rotor 9 rotatably provided inside the cam ring 8, and the cam ring 8. And a pair of side plates 1 0 and 1 1 arranged on both sides of

The drive shaft 3 has a driven pulley 19 for driving transmission attached to the other end projecting from the pump body 6, and the power of the engine is transmitted through a belt (not shown) wound around the driven pulley 19. It is supposed to be

As shown in FIG. 3, the cam ring 8 is provided with pump housings by locating pins 1 3 and 1 3 fitted in a pair of small semicircular pin receiving grooves 8b and 8c formed at approximately 180 positions on the outer peripheral surface. Positioning in the circumferential direction is made at 1, and the inner peripheral surface 8a is formed in a substantially elliptical shape.

The vane rotor 9 is integrally formed of a sintered alloy into a substantially disc shape, and a substantially annular pump chamber 14 is separated between the outer circumferential surface and the inner circumferential surface 8 a of the cam ring 8. . At the center of the vane rotor 9, a serration hole 9a through which the tip 3a of the drive shaft 3 penetrating the side plates 10, 11 is serrated is formed, and an outer peripheral portion is formed. , 1: 0 Slots 15 are radially formed at equally spaced positions in the circumferential direction. :

In addition, each slot 15 is provided with a thin plate-like vane 16 inside. A back pressure chamber 15a is formed at the bottom, in which the vanes 16 are made to slide toward the inner peripheral surface 8a of the cam ring 8 from the open end of the slot 15 while being held slidably in the direction. It is done.

In addition, as shown in FIG. 1, FIG. 3 and FIG. 5, this vane opening 9 is cut out at a portion other than the slot forming portion 17 where the respective slots 15 on the outer peripheral surface are formed. An arc-shaped lightening portion 18 is formed.

The respective slot forming portions 17 are respectively formed in a convex shape by the presence of the respective thin portions 18 and the slots 15 are respectively formed at substantially central positions in the circumferential direction.

The side plate 10 on one side is in pressure contact with the end face of the pump body 6, and as shown in FIG. 1, FIG. 2, FIG. 5 and FIG. A pair of radial left and right suction boats 20, 20 connected to the suction passage 4 provided in the pump body 6 is formed on the side, and the suction boats 20, 20,

A pair of first and second discharge ports 21 and 34 are formed at positions in a direction crossing with 20.

Further, third discharge ports 35 are formed at symmetrical positions sandwiching the cam ring 8 with respect to the first discharge port 21 in the side break 11 on the other side, and the first discharge port 35 is formed. 21 and the third discharge boat 35 communicate with each other in a pressure chamber 22 described later. In addition, an opening 21a having a small opening area of the first discharge port 21 is formed on the side of the side plate 10 opposite to the cam ring 8.

Furthermore, as shown in FIG. 1, FIG. 8 and FIG. 9, the second discharge port 34 has an opening area larger than that of the discharge port on the side opposite to the arc-shaped discharge port on the cam ring 8 side. The small opening 3 4 a is formed in a substantially fan shape from the fluid inlet to the outlet, and the opening area thereof is the opening 2 1 a of the first discharge port 21 and the third discharge point

The opening area is smaller than the opening area of 35, but larger than that of the conventional opening.

Also, at the maximum widening position of the opening 3 4 a of the second discharge port 34, the bridge 3 6 is erected, and on the outlet side of the bridge 36, a notch 37 for guiding the flow of the working fluid is formed over the entire length of the bridge 36.

In addition, the side plate 10 may have a pair of whiskers 21 b and 34 b in the direction opposite to the rotational direction of the respective ones of the discharge ports 21 and 34 on the same side. Grooves 40, 40 are formed.

As shown in FIG. 3 and FIG. 5, the respective whisker grooves 40, 40 are reverse to the rotating direction of the vane rotor 9 from the holes 21b, 34b of the respective discharge ports 21 and 34. It extends in a substantially arc shape in the direction, and is formed to be tapered from the proximal end 40 a to the distal end 40 b, and has a depth as shown in the vertical cross section of FIG. It is gradually shallower from the deepest proximal end 40 a to the distal end 40 b and is formed so as to rise slightly at the distal end 40 b. In addition, as shown in the cross section of FIG. 7, the bottom portion 40 c is formed in an acute angle shape and formed substantially in a V shape.

In addition, the distal end portion 40b is formed to be directed inward relative to the rotation locus line (shown by an alternate long and short dash line X) of each vane 16 passing substantially the center of the proximal end portion 40a. There is. That is, the tip portion 4 O b has a substantially central position of the radial length of the vane 16 whose extension line (P line) is rotationally moved to the vicinity of the winding groove 40 with the rotation of the vane rotor 9. It is formed more towards the base than it is.

Further, the tip 4 O b is longer than the conventional whiskers and is formed to extend, and the length thereof is at most the circumferential length between a pair of adjacent vanes 1 6 and 16. While being set to less than half of, it is further formed in a gradually tapered shape.

In addition, a pressure chamber 22 into which the hydraulic fluid discharged from the first to third discharge ports 21, 3 4 and 35 flows between the outer peripheral surface of the pump body 2 and the inner peripheral surface of the pump cover 7. Is provided. The pressure chamber 22 is connected in parallel to the discharge passage 5 provided in the pump body 6 and the drain passage 24 formed on the opposite side of the discharge passage 5 in the radial direction.

A variable throttling mechanism 25 is provided in the discharge passage 5, while a drain valve 26 responsive to the pressure difference across the variable throttling mechanism 25 is provided at the upstream end of the drain passage 24. It is broken.

The variable throttling mechanism 25 is housed in a spool housing hole 27 formed on the end face of the pump body 6 on the pressure chamber 22 side, and is accommodated in the spool housing hole 27 so as to be able to move back and forth. A spool 28 for changing the opening area of the discharge passage 5 and a spring 29 for biasing the spool 28 toward the pressure chamber 22 are provided.

The variable throttling mechanism 25 is operated by the balance between the hydraulic pressure of the pressure chamber 2 2 acting on one end of the spool 2 8 and the spring force of the spring 2 9. The opening area of the discharge passage 5 is set to be the largest at the initial position in which it abuts. The second discharge port 34 opens at a position facing the end face of the spool 28 in the side plate 10. On the other hand, the drain valve 26 has a spool housing hole 30 formed in the end face of the pump body 6 on the pressure chamber 22 side, a spool 31 housed in the spool housing hole 30 so as to be able to advance and retract, A spring 32 that biases the spool 3 1 to the pressure chamber 2 2 side, and a slip. When the groove 31 retracts, it is opened to the pressure chamber 22 according to the amount of retraction, and a drain port 33 constituting the open end of the drain passage 24 is provided.

The pressure on the downstream side of the variable throttling mechanism 25 is introduced via the pressure introducing passage 23 to the bottom portion 3 0 a side of the spool accommodation hole 30. Since one end of the spool 31 faces the pressure chamber 22 side, the pressure before and after the variable throttle mechanism 25 acts on the front of the spool 31 so that the drain valve 26 has its front and rear sides. In accordance with the differential pressure of the valve, the discharge flow rate from the drain port 33 to the drain passage 24 is controlled to be increased or decreased. .

Therefore, according to this embodiment, while the rotational speed of the drive shaft 3 (vane rotor 9) is low, the force of the spring 32 of the drain valve 26 with the variable throttle mechanism 25 opening the discharge passage 5 at maximum. Since the drain port 33 is closed by this, the supply flow rate of the discharge passage 5 also increases according to the increase of the rotation speed.

Then, when the rotational speed of the drive shaft 3 is increased to some extent and the differential pressure across the variable throttle mechanism 25 exceeds the set value, the spool 31 of the drain valve 26 responds to the differential pressure before and after that. Since the drain port 33 is opened and the hydraulic fluid is drained from the drain passage 24, the increase in the supply flow rate of the discharge passage 5 is suppressed. .

Furthermore, when the rotational speed of the drive shaft 3 increases from this state, the spool 2 8 of the variable throttle mechanism 2 5 retracts against the spring force of the spring 2 9 by the hydraulic pressure of the hydraulic fluid on the pressure chamber 2 2 side. The opening area of the passage 5 is gradually reduced. As a result, the supply flow rate of the discharge passage 5 gradually decreases, and so-called flow down characteristics can be obtained.

Further, according to this embodiment, when one vane 1 6 passes the tip portions 40 b and 40 b of the whisker grooves 40 and 40 with the rotation of the vane rotor 9, each discharge port is The high-pressure working fluid flowing back from the inside of the whiskers from the toe 2 1, 3 4 is the tip 4 0 b, 4 0 b of the whisker 4 0, 40, that is, the tip 4 0 b, 4 directed inward. It abuts on the radially inner end 16 a side of one side of the next side of the next adjacent 1 s 1 from 0 b or on the base side of the inner end 16 a. As a result, the load in the direction opposite to the rotational direction, ie, the moment, on the vane 16 is sufficiently reduced, and the force in the reverse direction to the vane rotor 9 is also significantly reduced. As a result, it is possible to suppress a decrease in pump efficiency.

In addition, by extending the tip portions 4 0 13 4 0 b of the respective whisker grooves 4 0 4 0, the radially inner end portion 1 6 a of one side surface of the adjacent vane 1 6 can be obtained. The directivity becomes stronger, and it becomes possible to more reliably formulate a high pressure working fluid in the direction of the inner end 16 a of one side.

In addition, the extension of the whisker grooves 40 can reduce the change in the discharge hydraulic pressure when the steering wheel is not largely rotated, for example, when the vehicle is traveling straight. That is, when the steering wheel is not largely rotated, the pressure difference between the discharge ports 21 and 34 and the pump chamber between the pair of vanes 16 and 16 rotationally moved in the vicinity is small. . And, the first and second discharge ports 21 and 34 are formed by the whisker grooves 40 and 40 into which the pump chamber which has been rotationally moved near the discharge ports 21 and 32 along with the rotation of the vane rotor 9 is extended. Of the pump chamber and the first and second discharge ports with respect to the rotational speed of the vane 16 The communication time with the ports 2 and 3 4 becomes long. Therefore, since the movement time of the hydraulic pressure in the discharge ports 21 and 32 to the pump chamber becomes long, the change in hydraulic pressure of the working fluid in the discharge ports 21 and 32 becomes small.

As a result, even when the steering wheel is slightly rotated, it is possible to reduce the pulsation of the hydraulic pressure in the discharge ports 21 and.

Further, in this embodiment, the opening 3 4 a of the second discharge port 34 is formed relatively large, and the opening area is set larger than that of the conventional one. The eccentric movement to the upper side (the first discharge point 21 side) in Fig. 1 of the course 9 is prevented.

That is, the first discharge port 21 side has a large opening area together with the third discharge port 35, while the second discharge port 34 side has a single point. The hydraulic pressure passing through the second discharge port 34 is greater than the hydraulic pressure passing through the first and third discharge ports 21 and 35. For this reason, the vane rotor 9 is pushed upward to the first and third discharge ports 21 and 35, that is, in FIG. 1, by the oil pressure on the high pressure second discharge port 34 side during operation of the pump. And it moves eccentrically. Therefore, since the tip of each vane 16 in the vicinity thereof is in sliding contact with the inner peripheral surface of the cam ring 8 with a strong force, the frictional resistance may be increased and the pump efficiency may be reduced. However, since the opening area of the opening 3 4 a of the second discharge port 34 is set large as in the present embodiment, the discharge pressure on the side of the first discharge port 21 is almost uniformly balanced. Thus, the occurrence of the eccentric motion of the vane rotor 9 can be suppressed. As a result, it is possible to reduce the occurrence of a large local sliding friction resistance of each vane 16 on the inner circumferential surface 8 a of the cam ring 8. Therefore, it is possible to prevent a decrease in pump efficiency.

In addition, it is a matter of course that the rigidity around the second discharge port 34 can be secured by bridging the bridge 36 at the maximum widening position of the opening 3 4 a of the second discharge port 34. The diaphragm effect is exhibited by the bridge 36, and the control accuracy of the pie mouth pressure by the variable diaphragm mechanism 25 can be increased. · Furthermore, since a notch 3 7 for guiding the flow of the working fluid is formed on the outlet side of the bridge 36 over the entire length of the bridge 36, the working fluid to the discharge passage 5 is cut by the notch 3 7. It is possible to properly control the flow direction (arrow in FIG. 1) of the valve, and as a result, high control accuracy of the variable throttle mechanism 25 can be obtained.

FIGS. 10 to 13 show another embodiment, in which the structure of the pump housing is different from that of the previous one in the structure of the vane pump, but the other basic structure is the same. That is, the pump housing 50 is closed by a rear plate 51 which is a plate member whose rear end opening is fixed to the pump housing 50 by a pole, and the inside of the pump housing 50 has the cam ring 52. And a vane rotor 53 formed of a sintered alloy material rotatably provided at an inner portion of the cam ring 52 is accommodated and disposed, and a side plate 54 at one side is disposed at one side of the cam ring 52. ing. Further, the drive shaft 55 passing through the pump housing 50 has a tip end portion 5 5 a bearing in a bearing hole 5 1 b formed substantially at the center of the rear plate 51, and the tip end portion 5 5 A portion closer to a is serration-bonded to the center hole 53a in the center of the vane rotor 53, while the proximal end is rotatably supported by a pole bearing 56.

Further, vanes (not shown) are radially provided in a plurality of slots of the vane rotor 53, and the pump chamber formed between the vanes is rotated by the vane rotor 53. The suction section is formed in the portion where the volume is changed and the volume is increased by this change, and the discharge section is formed in the portion where the volume is decreased.

The pump chamber is in communication with the high pressure chamber 58 formed in the internal recess of the pump housing 50 by the communication hole 57 of the side plate. Also, as shown in FIG. 11, the suction port 59 provided in the pump housing 50 has a pair of left and right suction ports 60, 60 formed in the rear plate 51, and an internal low pressure passage 61. It communicates with the pump chamber via

A flow rate control valve 62 is provided between a high pressure passage (not shown) in communication with the high pressure chamber 58 and the low pressure passage 61. The high pressure chamber 58 is provided with the flow control valve 62. Led to The surplus of the discharged oil is returned to the low pressure passage 61 to control the working fluid discharged from the discharge hole outside the figure to a constant amount.

The rear plate 51 is integrally formed of an aluminum alloy material, and as shown in FIGS. 10 to 12, the inner end surface 51 a is moved along with the rotation of the vane rotor 53. As shown in FIG. 1, the inner end face 5 1 a is in sliding contact with at least one side face 5 3 b of the inner rotor 5 3. As also shown in 3, the minute oil reservoirs 63 are formed innumerably.

The oil reservoir portion 63 is innumerably formed by intersection grooves of linear notches 64 formed in random directions on the surface of the inner end surface 51a by so-called lapping. The size is very small, about 0.3 a, or slightly smaller.

Therefore, an oil film is formed between the inner end surface 5 1 a and the side surface 5 3 b of the vane rotor 5 3 by the lubricating oil accumulated in the innumerable oil reservoirs 63, The lubricating performance between both members 5 1 a and 5 3 b is enhanced, and the occurrence of the wear of the inner end surface 5 1 a of the rear plate 51 having hardness lower than that of the vane rod 53 can be sufficiently prevented. In addition, since the oil reservoir 63 is formed by lapping, the forming operation is simple and micro-processing is possible.

Furthermore, since oil reservoir 63 is extremely small as described above, the sealability with pump housing 50 is reduced even if it is formed on the entire surface of inner end face 51a. There is nothing to do.

It is also possible to form the minute oil reservoir portion 6 3 on only one side 5 3 b of the vane 5 3, and further, inside of the side 3 5 b and the rear plate 5 1 It is also possible to form on both the end face 5 1 a.

The technical ideas other than the claims that can be grasped from the embodiment are described below. :

(1) The pump has a cam ring housed in a housing.

A side plate disposed on the side of the cam ring; A pair of discharge ports that are formed at target positions in the substantially radial direction of the side plate;

A rotor rotatably accommodated in the cam ring and rotationally driven by a drive shaft;

A vane pump comprising: a vane rotatably held in the direction of the inner circumferential surface of the cam ring in a plurality of slots formed along the radial direction on the outer circumferential portion of the rotor.

A third discharge port is formed on the opposite side of the one first discharge port across the cam ring, and the first and third discharge ports are formed between the pump housing and the cam ring. The opening area of the other second discharge port is formed large so as to be close to the total opening area of the first and third discharge ports, while being formed in two systems communicating with the pressure chamber. Vane pump.

According to the present invention, since the opening area of the opening of the second discharge port is set large, the discharge pressure on the side of the first discharge port is almost evenly balanced, so that the eccentricity of the low temperature can be reduced. The occurrence can be suppressed. As a result, it is possible to reduce the occurrence of a large local sliding friction resistance of each vane on the inner circumferential surface of the cam ring. Therefore, it is possible to prevent a decrease in pump efficiency.

(2) The vane pump according to (1), wherein the opening of the second discharge port is formed in a fan-like shape from the inlet to the outlet of the fluid.

According to the present invention, since the opening shape of the opening of the second discharge port is expanded in a substantially fan-like shape, good flowability of the working fluid in the direction of the variable throttle mechanism can be obtained, and the discharge pressure Can be effectively reduced.

(3) The bridge is installed at the maximum widening position of the opening of the second discharge port, and a notch for guiding the flow of the working fluid is formed on the outlet side of the bridge over the entire length of the bridge. The pump according to claim 1 or 2, which is characterized by the present invention. .

According to the present invention, the bridge is installed at the widest position of the opening of the second discharge port. As a result of the provision, it is possible to secure the rigidity around the second discharge port, and of course, the throttling effect is exhibited by this ridge, so that the control accuracy of the pilot pressure by the variable throttling mechanism can be increased.

Furthermore, since the notch for guiding the flow of the working fluid is formed over the entire length of the ridge, the notch enables the flow direction of the working fluid to the discharge passage to be properly controlled, and as a result, High control accuracy of the variable aperture mechanism can be obtained.

(4) With a cam ring housed in the pump housing,

A plate member closing an end opening of the pump holder and abutting on a side surface of the force mulling;

A rotor rotatably accommodated in the cam ring and having one side in sliding contact with the inner end face of the plate member when rotated by a drive shaft;

A vane pump held in a plurality of slots formed in a radial direction on an outer peripheral portion of the rotor in a manner such that the vanes can be retracted toward the inner peripheral surface of the cam ring;

A minute oil reservoir is formed on at least one of the inner end surface of the plate member and one side surface of the rotor.

According to the present invention, the lubricating oil accumulated in the minute oil reservoir portion always forms an oil film between the inner end surface and the side surface of the mouth, so that the lubricating performance between the both is high. As a result, the occurrence of sliding wear between the rotor and the rear plate can be sufficiently prevented.

(5) The vane pump according to (4), characterized in that the oil reservoir portion is formed by intersection grooves of linear notches formed in random directions.

(6) The vane pump according to (5), characterized in that the intersection concave grooves of the linear notches formed in the random direction are formed by lapping. According to the present invention, since the oil reservoir is formed by lapping, the forming operation is simple and minute processing is possible.

The present invention is not limited to the configuration of each of the above embodiments, and, for example, the oil reservoir It is also possible to apply the ridge portion to the first embodiment, and in this case, it is formed on the opposing surface of both side plates 10 1 and 11, that is, the opposing surface in sliding contact with both sides of the vane rotor Alternatively, it may be formed on both sides of the vane rotor.

Claims

The scope of the claims

1. The cam ring housed in the pump housing.

A side braze disposed at a side of the cam ring and having an outlet port formed therein;

A vane rotatably held in the direction of the inner peripheral surface of the cam ring in a plurality of slots formed radially along the outer periphery of the rotor;

A vane groove formed in an inner surface in sliding contact with the rotor of the side plate and communicating with the discharge point;

The whiskers are formed to be gradually tapered from the discharge port along the direction opposite to the rotational direction of the rotor, and the tip of the whiskers passes through the base of the whiskers of each vane. A vane pump characterized in that it is formed to be directed inward of the rotation locus line.

2. The extension line of the tip of the whisker is characterized in that it is directed to the base rather than the substantially central position of the radial length of the vane rotated in the vicinity of the whisker as the rotor rotates. The vane pump according to claim 1.

3. The vane pump according to claim 1 or 2, wherein the tip of the whisker groove is formed to extend in the vane direction in which it is rotationally moved near the whisker groove as the rotor rotates.