JP2007120436A - Vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve lubricity of an inner peripheral surface of a cam ring by stably staying and holding oil by uniformly distributing the oil to respective places of the inner peripheral surface of the cam ring by easily machining the inner peripheral surface of the cam ring. <P>SOLUTION: This vane pump P slidingly contacts the outer end 12a of respective vanes 12 with a cam surface 8b of the cam ring 8 by rotation of a rotor 11 by fitting the vanes 12 to a plurality of respective grooves arranged in a plurality of positions in the peripheral direction of the rotor 11 by pointing in the radial direction by arranging the rotor 11 inside the cam ring 8. A twill line-shaped grinding pattern 30 is attached to the cam surface 8b of the cam ring 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vane pump.

  In general, a vane pump has a rotor disposed inside a cam ring, and a vane is fitted into each of a plurality of grooves provided in a plurality of positions in the circumferential direction of the rotor in a radial direction, and the outer end of each vane is rotated by rotation of the rotor. Is in sliding contact with the inner peripheral surface of the cam ring.

In the vane pump of Patent Document 1, random streaks are provided on the inner peripheral surface of the cam ring in order to prevent wear and seizure of the inner peripheral surface of the cam ring and the sliding contact portion of the vane, and lubricity of the inner peripheral surface of the cam ring. The thing which is going to improve is disclosed.
Real fairness 4-17834

  In the vane pump of Patent Document 1, it is difficult to provide random streaks on the inner peripheral surface of the cam ring by machining with a grindstone or the like, and oil is evenly distributed to various locations on the inner peripheral surface of the cam ring and is stable. It is difficult to retain and hold the film.

  In addition, when machining a large number of parallel fine grooves that are perpendicular or oblique to the axial direction of the cam ring, such as by oscillating the inner peripheral surface of the cam ring, each part of the groove along the circumferential direction of the initial cam ring The oil present in the gas moves as the vane slides, and the oil cannot be stably retained and held in these places, which may cause the oil film to break.

  The problem of the present invention is that the inner peripheral surface of the cam ring is simply machined so that oil is evenly distributed and stably retained and held at various locations on the inner peripheral surface of the cam ring. It is to improve lubricity.

  According to the first aspect of the present invention, a rotor is disposed inside the cam ring, a vane is fitted into each of a plurality of grooves provided in a plurality of positions in the circumferential direction of the rotor in a radial direction, and each vane is rotated by rotation of the rotor. In the vane pump in which the outer end is slidably contacted with the inner peripheral surface of the cam ring, the inner peripheral surface of the cam ring is provided with a twill-like grinding pattern.

  According to a second aspect of the present invention, there is provided the vane pump manufacturing method according to the first aspect, wherein the cam ring is supported by a grindstone that moves along the axial direction of the cam ring while rotating and supporting the cam ring once. The first peripheral step of oscillating the cam ring and the inner peripheral surface of the cam ring by a grindstone that moves in the opposite phase to the first step along the axial direction of the cam ring during the next one rotation of the cam ring following the first step. And a second step of oscillating grinding.

(Claim 1)
(a) By attaching a twill-shaped grinding pattern to the inner peripheral surface of the cam ring, oil can be evenly distributed to the various locations of the twill that are evenly distributed on the inner peripheral surface of the cam ring, and The distributed oil can be stably retained and held without moving as the vane slides. Accordingly, the wear and seizure of the cam ring at the sliding contact portion between the inner peripheral surface of the cam ring and the vane can be prevented without causing an oil film breakage on the inner peripheral surface of the cam ring.

(Claim 2)
(b) The first step of oscillating the inner peripheral surface of the one-turn cam ring and the second step of oscillating the inner peripheral surface of the next one-turn cam ring in the opposite phase to the first step are simplified. By machining, the inner peripheral surface of the cam ring can be provided with a twill-like grinding pattern.

  1 is a partially cutaway front view of the vane pump, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a front view showing the cam ring in FIG. 1, and FIG. FIG. 5A is a front view, FIG. 5B is a cross-sectional view, FIG. 5 is a view taken along the line V-V in FIG. 4A, and FIG. 5A is an arrow showing the processing result of the first step. FIG. 5B is an arrow view showing the processing result of the second step.

  A constant capacity type vane pump P according to an embodiment of the present invention is driven by power of a driving source, for example, an internal combustion engine, and hydraulic fluid as fluid is used as a fluid pressure utilization device, for example, hydraulic power steering or hydraulic type for a vehicle. Used as an oil pump for supplying to a continuously variable transmission.

  As shown in FIGS. 1 and 2, the vane pump P is sandwiched between the pump unit U, the housing 1, a cover 2 in which a housing chamber 3 including a recess for housing the pump unit U is formed, and the housing 1 and the cover 2. The seal plate which covers the opening of the storage chamber 3 and forms the passage of hydraulic oil by covering the openings of the plurality of grooves formed in the housing 1 and the openings of the plurality of grooves formed in the cover 2. 4. The seal plate 4 is fastened and fixed to the housing 1 together with the cover 2 by a plurality of bolts 1A.

  A drive shaft 5 of a vane pump P that is rotationally driven by the power of the internal combustion engine is rotatably supported by the housing 1 via a slide bearing 6 that is press-fitted into a shaft hole provided in the housing 1. The cover 2 is rotatably supported by a slide bearing 7 that is press-fitted into a shaft hole provided in the side wall of the cover 2 that becomes the bottom wall 3a of the storage chamber 3.

  The pump unit U includes an annular cam ring 8 having a circular outer peripheral surface 8a and a cam surface 8b formed by an inner peripheral surface having an approximate shape of an ellipse, and a first side plate 9 that covers the side surface of the cam ring 8 on the housing 1 side. And a pump body having a second side plate 10 that covers the side surface of the cam ring 8 on the cover 2 side, a rotor 11 disposed in the cam ring 8 in a space formed in the pump body, and the rotor 11 Are fixed to the first side plate 9 and a plurality of vanes 12 that are slidably fitted in a radial direction in a plurality of vane grooves 11a provided at equal intervals in the circumferential direction. And a vane guide 13 housed in an annular housing groove 11 c formed on the first side plate 9 side of the rotor 11.

  The cam ring 8 and the first side plate 9 are each provided with a pair of through holes 14 and 15 provided in the diametrical direction, and a pair of positioning pins (not shown) penetrating the through holes 14 and 15 are provided. One end is press-fitted into a pair of blind holes provided in the second side plate 10 so that the pump unit U is integrated. Then, the other end portions of the pair of positioning pins in a state of protruding from the first side plate 9 are respectively press-fitted into a pair of blind holes provided in the housing 1 through the holes of the seal plate 4. Thus, after the pump unit U is assembled to the housing 1, the drive shaft 5 is inserted from the slide bearing 6 side, the journal portion 5a is supported by the slide bearing 6, and the coupling portion 5b is connected to the rotor 11 and the spline. After the coupling and the drive shaft 5 and the rotor 11 are rotated together, the retaining ring 16 is mounted, and then the cover 2 is mounted on the housing 1 so that the slide bearing 7 is fitted to the journal portion 5c on the distal end side. Assembled to.

  The outer end 12a in the radial direction of each vane 12 is configured to come into contact with the cam surface 8b of the cam ring 8, and is between the cam surface 8b and the outer peripheral surface of the rotor 11, and includes the first and second side plates 9. A plurality of pump chambers 17 are formed by dividing the space between the plurality of vanes 12 by the spaces between the plurality of vanes 12.

  Further, the rotor 11 is formed with a vane back pressure chamber 11 b communicating with the bottom of each vane groove 11 a, and is discharged from the pump chamber 17 between the bottom wall 3 a of the storage chamber 3 and the second side plate 10. A high pressure chamber 19 into which a part of the hydraulic oil is introduced through a communication path 18 formed in the second side plate 10 is formed. Further, the second side plate 10 has each side surface on the rotor 11 side. An annular supply groove 21 communicating with the vane back pressure chamber 11b and a plurality of supply paths 20 communicating the high pressure chamber 19 and the supply groove 21 are formed. Then, when the vane pump P discharges hydraulic oil having a discharge pressure equal to or higher than a predetermined value, the hydraulic oil in the high pressure chamber 19 is supplied to each vane back pressure chamber 11b through the supply path 20 and the supply groove 21. Each vane 12 receives a force pushed radially outward in the vane groove 11a, whereby the outer end 12a of each vane 12 is pressed against the cam surface 8b, and the outer end 12a of each vane 12 and the cam surface 8b Sealing is performed.

  As shown in FIGS. 1 and 3, the cam ring 8 has four suction ports 22 each having a pair of grooves provided on the outer peripheral surface 8a and the cam surface 8b on each side surface, and on both side surfaces thereof. In addition, two discharge ports 23 each including a pair of grooves 23a provided to be opened only on the cam surface 8b and through holes 23b communicating with the grooves 23a are provided at positions opposed to each other in the diameter direction. The suction port 22 and the discharge port 23 communicate with the pump chamber 17.

  As shown in FIG. 3, the first side plate 9 through which the drive shaft 5 is inserted is formed with a radial notch and a pump chamber at a position aligned with the suction port 22 on the first side plate 9 side of the cam ring 8. A pair of suction ports 24 communicating with the discharge port 23 is formed, and a pair of discharge ports 25 including a through hole and communicating with the pump chamber 17 are formed at a position aligned with the discharge port 23.

  As shown in FIG. 2, the cover 2 is provided with an inlet passage 26 extending in the axial direction. An inlet 26a of the inlet passage 26 communicates with a reservoir storing hydraulic oil via an oil pipe, and an outlet 26b of the inlet passage 26 is formed between the peripheral wall surface of the storage chamber 3 and the outer peripheral surface of the pump unit U. Communicated with the annular passage 27. Therefore, the annular passage 27 communicates with the suction port 22 of the cam ring 8 and the suction port 24 of the first side plate 9.

  On the other hand, the housing 1 is provided with a discharge passage 28 formed of a groove covered with the seal plate 4. The inlet of the discharge passage 28 communicates with the discharge port 23 of the cam ring 8 and the discharge port 25 of the first side plate 9 through an opening provided in the seal plate 4, and the outlet of the discharge passage 28 is connected to the fluid pressure utilization device. It communicates with the hydraulic oil passage.

  When the vane pump P configured as described above is operated and the rotor 11 starts to rotate integrally with the drive shaft 5 in the rotation direction A, the outer end 12a of each vane 12 comes into sliding contact with the cam surface 8b. The hydraulic oil passing through the annular passage 27 is efficiently sucked and discharged. That is, hydraulic oil sucked from the reservoir through the inlet passage 26 to the pump chamber 17 whose volume is increasing with the rotation of the rotor 11 passes through the annular passage 27 and is in communication with the pump chamber 17. The air is sucked from a certain suction port 22 and suction port 24. Then, after the volume of the pump chamber 17 reaches the maximum, the hydraulic oil in the pump chamber 17 is discharged from the pump chamber 17 whose volume is decreasing to the discharge port 23 and the discharge port 25 that are in communication with each other. The oil is supplied to the hydraulic oil passage of the fluid pressure utilization device through the discharge passage 28.

  However, in the vane pump P, in order to improve the lubricity of the inner peripheral surface (cam surface 8b) of the cam ring 8 in which the outer end 12a of each vane 12 is in sliding contact with the rotation of the rotor 11, the cam surface 8b of the cam ring 8 is improved. A twill-shaped grinding pattern 30 was applied.

  As shown in FIG. 5, the cross-shaped grinding pattern 30 includes a large number of first fine grooves 31 that are oblique to the axial direction of the cam ring 8 and are parallel to each other at a certain depth, and the width of the cam surface 8 b of the cam ring 8. A large number of second microgrooves that are oblique to the axial direction of the cam ring 8 and are parallel to each other at a constant depth so as to be symmetrical with the first microgroove 31 with respect to a circumferential line L that passes through the center of the direction. 32. On the cam surface 8 b of the cam ring 8, the hydraulic oil stays and is held at various locations in the cross of the first fine groove 31 and the second fine groove 32 that intersect with each other. Lubricity with the outer end 12a of the vane 12 is improved.

The cross-shaped grinding pattern 30 of the cam ring 8 is machined as follows (FIGS. 4 and 5).
(1) The cam ring 8 is gripped by the chuck at the tip of the spindle head of the grinding machine.

  (2) As a first step, the cam surface 8b of the cam ring 8 is oscillated by the grindstone 40 that reciprocates (oscillates) along the axial direction of the cam ring 8 while the cam ring 8 is rotated and supported. While rotating the grindstone 40, a predetermined amount is cut in the radial direction of the cam surface 8b and reciprocated along the axial direction of the cam ring 8 to form the aforementioned first fine groove 31 on the cam surface 8b.

  (3) The cam surface 8b of the cam ring 8 is moved by the grindstone 40 that reciprocates (oscillates) in the opposite phase to the first step along the axial direction of the cam ring 8 during the next one rotation of the cam ring 8 as the second step. Oscillate grinding. The reverse phase means that at each point on the cam surface 8b of the cam ring 8, the moving speed and direction of the grindstone 40 passing through the point in the first step and the moving speed and direction passing through the point in the second step are reversed. If the point passes upward in the first step, the second step means passing the point downward at the same speed. While rotating the grindstone 40, a predetermined amount is cut in the radial direction of the cam surface 8b and reciprocated along the axial direction of the cam ring 8 to form the aforementioned second fine groove 32 on the cam surface 8b.

  In the vane pump P, the cam surface 8b of the cam ring 8 has an elliptical shape, and the grindstone 40 has a predetermined amount along the radial direction of the cam surface 8b at each rotational angle position of the cam ring 8 described in (2) and (3) above. Is moved by the amount of movement obtained by combining the notch amount and the change amount of the ellipse radius at the rotational angle position of the cam surface 8b.

According to the present embodiment, the following operational effects can be obtained.
(a) By providing the cross-shaped grinding pattern 30 on the cam surface 8b of the cam ring 8, the oil can be evenly distributed to the various portions of the cross-hatched evenly distributed on the cam surface 8b of the cam ring 8. The oil distributed to each of these locations can be stably retained and held without moving as the vane 12 slides. Thus, the wear and seizure of the sliding surface between the cam surface 8b of the cam ring 8 and the vane 12 can be prevented without causing the oil film to be cut off on the cam surface 8b of the cam ring 8.

  (b) A first step of oscillating the cam surface 8b of the rotating cam ring 8 and a second step of oscillating the cam surface 8b of the next rotating cam ring 8 in the opposite phase to the first step, By a simple machining process, a twill-like grinding pattern 30 can be applied to the cam surface 8b of the cam ring 8.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, the hole provided in the cam ring may be a non-through hole, or may be opened only on one of the inner peripheral surface or the outer peripheral surface of the cam ring.

FIG. 1 is a front view showing a vane pump partially cut away. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a front view showing the cam ring of FIG. 4A and 4B show the oscillating grinding state of the cam ring, where FIG. 4A is a front view and FIG. 4B is a cross-sectional view. 5A and 5B are arrow views along the line VV in FIG. 4A, where FIG. 5A is an arrow view showing the processing result of the first step, and FIG. 5B is an arrow showing the processing result of the second step. FIG.

Explanation of symbols

P Vane pump 8 Cam ring 8b Cam surface (inner peripheral surface)
11 Rotor 12 Vane 12a Outer end 30 Twill-shaped grinding pattern 40 Grinding wheel

Claims (2)

A rotor is arranged inside the cam ring, vanes are fitted into a plurality of grooves provided in a radial direction at a plurality of circumferential positions of the rotor, and the outer end of each vane is connected to the inner periphery of the cam ring by the rotation of the rotor. In a vane pump that is in sliding contact with the surface,
A vane pump characterized in that the inner peripheral surface of the cam ring is provided with a twill-like grinding pattern. It is a manufacturing method of the vane pump according to claim 1,
A first step of oscillating the inner peripheral surface of the cam ring with a grindstone that moves along the axial direction of the cam ring while rotating and supporting the cam ring once;
Following the first step, a second step of oscillating the inner peripheral surface of the cam ring with a grindstone that moves in the opposite phase to the first step along the axial direction of the cam ring during the next rotation of the cam ring. The manufacturing method of the vane pump which has.

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