JP2006307756A - Vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance volume efficiency of a vane pump, by reducing clearance between a cover and a cam ring. <P>SOLUTION: This vane pump has a pressure loading mechanism for pressing a side plate to the cover via a rotor and the cam ring 4 by working fluid pressure. A projection part 41 extending along a side surface of the cover when stopping operation and a recessed part 42 extending along the cover deformed in the operation, are formed on a side surface opposed to the cover of the cam ring 4, to reduce the clearance between the cover and the cam ring 4 deformed by receiving driving force and the working fluid pressure of the pressure loading mechanism in the operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of a vane pump used as a fluid pressure source of, for example, a vehicle power steering apparatus.

  Conventionally, as this kind of vane pump, the one disclosed in Patent Document 1 includes a rotor that is rotatably accommodated in a body, a plurality of vanes that slidably protrude from the rotor, and a tip end portion of each vane. The cam ring that defines the vane chamber, the side plate that defines the vane chamber by sliding one side end portion of each vane, and the vane chamber by sliding the other side end portion of each vane. A cover to be defined, a suction passage through which the working fluid flows into the vane chamber in a suction stroke in which the vane chamber expands as the rotor rotates, and a working fluid from the vane chamber in a discharge stroke in which the vane chamber contracts in accordance with the rotation of the rotor And a pressure loading mechanism that presses the side plate against the cover via the rotor and the cam ring by the working fluid pressure guided to the discharge passage.

By this pressure loading mechanism, the side surface of the side plate is pressed against one side surface of the rotor, and the other side surface of the rotor is pressed against the cover, thereby reducing the gap between the side plate and the cover with respect to the rotor and cam ring that define the vane chamber. The working fluid is prevented from leaking from the vane chamber through these gaps into the body.
JP 2001-020871 A

  However, in such a conventional vane pump, the pressure loading mechanism drives the side plate in the direction of the rotation axis of the rotor by the pump discharge pressure, the side plate presses the rotor and cam ring against the cover, and the pressure is increased in the vane chamber. Since the side surface of the cover is deformed into a concave shape by applying a working fluid pressure, the gap between the cover and the cam ring is partially increased, and the gap between the cover and the rotor is increased, resulting in a high pressure in the vane chamber. The working fluid leaked into the body through these gaps, causing the volumetric efficiency of the vane pump to decrease.

  The present invention has been made in view of the above problems, and an object of the present invention is to increase the volumetric efficiency of the vane pump by reducing the gap between the cover and the cam ring.

  The present invention includes a rotor that is rotatably housed in a body, a plurality of vanes that slidably protrude from the rotating rotor, a cam ring that defines a vane chamber by slidingly contacting the tip of each vane, A side plate that slidably contacts one side end of the vane to define the vane chamber, a cover that slidably contacts the other side end of each vane to define the vane chamber, and the rotation of the rotor A suction passage through which the working fluid flows into the vane chamber during the suction stroke in which the vane chamber expands, a discharge passage through which the working fluid flows out from the vane chamber during the discharge stroke in which the vane chamber contracts as the rotor rotates, and the discharge passage. A vane pump including a pressure loading mechanism that presses a side plate against a cover via a rotor and a cam ring by a working fluid pressure is assumed.

  According to the present invention, a cover and a cam ring that form a convex portion that bulges on at least one of a side surface of the cam ring and a side surface of the cover that are opposed to each other, and are deformed by the driving force and the working fluid pressure of the pressure loading mechanism during operation. It was set as the structure which reduces the clearance gap between these through this convex part.

  Further, according to the present invention, a groove surrounding the contact surface that contacts the cam ring is formed in the cover, and the deformation of the contact surface due to the driving force of the pressure loading mechanism and the working fluid pressure is suppressed via the groove.

  According to the present invention, the convex portion formed on at least one of the side surface of the cam ring and the side surface of the cover bulges corresponding to the cover that is deformed by the driving force and the working fluid pressure of the pressure loading mechanism. By making the surface pressure distribution between the cover and the cam ring uniform, the gap between the cover and the cam ring is reduced. And since a cam ring follows according to a deformation | transformation of a cover, the clearance gap between a cover and a rotor is reduced. As a result, it is possible to prevent the working fluid having a high pressure in the vane chamber from leaking into the body through the gap between the cover and the cam ring and between the cover and the rotor, thereby increasing the volumetric efficiency of the vane pump.

  Further, according to the present invention, since the cover is formed with a groove surrounding the contact surface that contacts the cam ring, the cover has a portion where the groove is opened by receiving the driving force of the pressure loading mechanism and the working fluid pressure when the vane pump is operated. By deform | transforming, it suppresses that the site | part which has a contact surface with respect to a cam ring deform | transforms. As a result, there is no region where the surface pressure is locally increased between the side surface of the cam ring and the side surface of the cover when the vane pump is operated, and the gap between the cover and the cam ring is reduced. And the clearance gap between a cover and a rotor can be reduced by suppressing a deformation | transformation to the center part of a cover. As a result, it is possible to prevent the working fluid having a high pressure in the vane chamber from leaking into the body through the gap between the cover and the cam ring and between the cover and the rotor, thereby increasing the volumetric efficiency of the vane pump.

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

  First, FIG. 1 and FIG. 2 show an example of a vane pump to which the present invention can be applied.

  As shown in FIGS. 1 and 2, the vane pump includes a rotor 6 that is rotatably accommodated in a body 1, a plurality of vanes 7 that slidably protrude from the rotor 6, and a tip portion of each vane 7 in sliding contact. The cam ring 4 defining the vane chamber (pump chamber), the side plate 3 defining the vane chamber by slidingly contacting one side end of each vane 7, and the other side end of each vane 7 The cover 10 that defines the vane chamber by sliding contact with each other, the suction passage 12 that allows the working fluid to flow into the vane chamber in the suction stroke in which the vane chamber expands as the rotor 6 rotates, and the vane as the rotor 6 rotates. It is mainly composed of a discharge passage 14 through which the working fluid flows out from the vane chamber in the discharge stroke in which the chamber contracts.

  The suction passage 12 communicates with a tank (not shown), and the discharge passage 14 communicates with a fluid pressure actuator (not shown).

  A shaft 9 passes through and is connected to the rotor 6 at the center thereof. The shaft 9 is supported by the body 1 via a bearing 8 so that the shaft 9 is rotatable, and its tip is rotatably supported by a cover 10 via a bearing 11.

  The cam ring 4 has an inner peripheral surface 4a that slides the vanes 7 to displace them in the radial direction. When the shaft 9 is rotated by a drive source (not shown), the rotor 6 is rotated together with the shaft 9, and each vane 7 slides in and out of the rotor 6 in the radial direction while sliding the outer peripheral end portion on the inner peripheral surface 4 a of the cam ring 4. Expand and contract the vane chamber.

  The rotor 6 rotates counterclockwise as indicated by an arrow K in FIG. 2, and working fluid is discharged from the vane chamber contracting in the two discharge regions T to the discharge passage 14, while in the two suction regions S. The working fluid is sucked into the vane chamber from the expanding suction passage 12.

  The suction passage 12 branches into a bifurcated shape in the cover 10 and opens into two suction regions S. A communication hole 13 is formed in the cam ring 4 so as to pass through in the direction of the rotation axis of the rotor 6. The communication hole 13 communicates with the suction passage 12, so that the working fluid enters not only the cover 10 side but also the vane chamber from the body 1 side. Inhaled.

  The discharge passage 14 defined between the back surface of the side plate 3 and the body 1 serves as a pressure chamber that applies driving pressure to the side plate 3, and presses the side plate 3 against the cover 10 via the rotor 6 and the cam ring 4. Configures the pressure loading mechanism. The side surface of the side plate 3 is pressed against one side surface of the rotor 6 by the pressure loading mechanism, and the other side surface of the rotor 6 is pressed against the side surface of the cover 10, and the side plate 3 against the cam ring 4 defining the vane chamber It is possible to reduce the gap between the covers 10 and prevent the working fluid from leaking into the body 1 through the gaps from the vane chamber.

  The side plate 3 and the cam ring 4 are accommodated so as to be slidable in the rotational axis direction of the rotor 6 with respect to the inner wall portion 2 of the body 1. Two positioning pins penetrating the side plate 3, the cam ring 4 and the cover 10 are provided. Two holes 5 extending in the direction of the rotation axis of the rotor 6 are formed in the cam ring 4, and the positioning pins are fitted into the holes 5.

  The body 1 is formed with four bolt holes 16 and the cover 10 is also formed with four bolt holes (not shown). The four bolts are inserted into the bolt holes of the cover 10 and screwed into the bolt holes 16 of the body 1, whereby the cover 10 is fastened to the body 1 at four locations.

  By the way, the pressure loading mechanism drives the side plate 3 in the direction of the rotational axis of the rotor 6 by the working fluid pressure guided to the discharge passage 14, and the side plate 3 presses the cover 10 against the rotor 6 and the cam ring 4, and the bolts are fastened at four locations. The side surface of the cover 10 is deformed into a concave shape with respect to the portion. For this reason, the gap between the cover 10 and the cam ring 4 is partially increased, and the working fluid having a high pressure in the vane chamber may leak into the body 1 through this gap.

  Hereinafter, the problem of the above vane pump will be described in detail with reference to FIGS.

  FIG. 3 shows the result of analyzing the deformation distribution of the cover 10 by the driving force of the pressure loading mechanism and the working fluid pressure by the finite element method.

  FIG. 4 is a diagram schematically showing the deformation distribution of the cover 10 based on the analysis result of FIG. The deformation amount of the cover 10 increases in the order of the hatching area 101, the hatching area 102, and the hatching area 103 shown in FIG.

  3 and 4, the deformation amount of the cover 10 is the largest at the center portion facing the rotor 6, and decreases as the distance from the center portion increases, and the portion near the bolt hole 16 in the circumferential direction of the cam ring 4 is the bolt hole. As can be seen from FIG.

  FIG. 5 is a cam ring layout diagram showing a region where the cam ring 4 faces the cover 10 as a cam ring joint 104.

  FIG. 6 is a diagram illustrating the deformation distribution diagram of FIG. 4 and the cam ring arrangement diagram of FIG. The cross-hatching portion 105 is a region that overlaps the hatching region 102 where the deformation amount of the cover 10 is medium in the cam ring joint portion 104. The cross-hatching portion 106 is a region that overlaps the hatching region 102 where the deformation amount of the cover 10 is relatively small in the cam ring joint portion 104.

  Since the cross hatching portion 106 has a smaller deformation amount than the cross hatching portion 105, the cam ring 4 and the cover 10 are mainly joined by the cross hatching portion 106, while the cross hatching portion 105 may have a gap. When a gap is generated in the cross hatching portion 105, the working fluid having a high pressure in the vane chamber leaks into the body 1 through the gap, and the volumetric efficiency of the vane pump is lowered.

  Therefore, the present invention forms a bulging convex portion on at least one of the side surface of the cam ring 4 and the side surface of the cover 10 facing each other, and deforms upon receiving the driving force and working fluid pressure of the pressure loading mechanism when the vane pump is operated. The gist is that the gap between the cover 10 and the cam ring 4 is reduced.

  Hereinafter, the embodiment shown in FIG. 7 will be described with respect to a specific example of the vane pump.

  In the present embodiment, as shown in FIGS. 7A and 7B, the cam ring 4 has a side surface facing the cover 10 along the cover 10 that is deformed by the driving force and the working fluid pressure of the pressure loading mechanism. The bulging convex part 41 is formed, and the surface pressure distribution between the cam ring 4 and the cover 10 is made uniform.

  The convex portion 41 is formed in an annular shape along the edge of the inner peripheral surface 4 a of the cam ring 4. A concave portion 42 is formed around the convex portion 41 in an annular shape. The concave portion 42 extends along the cover 10 which is deformed by receiving the driving force of the pressure loading mechanism and the working fluid pressure, and makes the surface pressure distribution between the cam ring 4 and the cover 10 uniform.

  As shown in FIG. 7A, the convex portion 41 is formed in a region facing the cross hatching portion 105 shown in FIG. 6 where the deformation amount of the cover 10 is relatively large, and the concave portion 42 is formed on the cover 10. It is formed in a region facing the cross hatching portion 106 shown in FIG.

  The annular concave portion 42 surrounds the convex portion 41 over the entire circumference, and the width of the rotor 6 in the radial direction changes so as to approximate the width of the cross hatched portion 106 shown in FIG.

  As shown in FIG. 7B, the convex portion 41 and the concave portion 42 are formed in a planar shape orthogonal to the rotation axis direction of the rotor 6. The recess 42 has a step 43 with a predetermined value h with respect to the protrusion 41. The illustrated dimensional difference is exaggerated and larger than the actual size for convenience, but in actuality, the dimension h of the step 43 is such that contact between the recess 42 and the cross-hatched portion 106 shown in FIG. For example, it is about several tens of micrometers to several hundreds of micrometers.

  Next, the operation and effect will be described.

  As the rotor 6 rotates, the vane chamber defined between the vanes 7 expands in the suction region S, sucks the working fluid from the suction passage 12, and contracts in the discharge region T to transfer the working fluid to the discharge passage 14. Discharge.

  The pressure loading mechanism drives the side plate 3 in the direction of the rotation axis of the rotor 6 by the working fluid pressure guided to the discharge passage 14 and presses the side plate 3 against the cover 10 via the rotor 6 and the cam ring 4. Since the central portion of the cover 10 is deformed in a concave shape with respect to the four bolt fastening portions by the working fluid pressure, the gap between the cover 10 and the cam ring 4 may partially increase.

  In response to this, in the present embodiment, the convex portion 41 formed on the side surface of the cam ring 4 facing the cover 10 bulges along the cover 10 that is deformed by the driving force and the working fluid pressure of the pressure loading mechanism. Thereby, the surface pressure of the convex part 41 with respect to the cover 10 is uniformly distributed at the time of the action | operation of a vane pump. For this reason, when the vane pump is operated, there is no portion where the surface pressure is locally increased between the side surface of the cam ring 4 and the side surface of the cover 10, and the gap between the cover 10 and the cam ring 4 can be reduced. And since the cam ring 4 follows according to a deformation | transformation of the cover 10, the clearance gap between the cover 10 and the rotor 6 can be reduced. Thereby, it is possible to prevent the working fluid having a high pressure in the vane chamber from leaking into the body 1 through the gap between the cover 10 and the cam ring 4, and to increase the volumetric efficiency of the vane pump.

  In the present embodiment, the protruding height of the side surface of the cam ring 4 is changed in two steps by the convex portion 41 and the concave portion 42, but this is not restrictive, and the protruding height of the side surface of the cam ring 4 is increased in three steps or more. It may be changed step by step, and the side surface of the cam ring 4 may be formed in a tapered shape. Thereby, the surface pressure distribution between the cam ring 4 and the cover 10 can be made more uniform.

  Next, another embodiment shown in FIG. 8 will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  In the present embodiment, four concave portions 42 are formed on the side surface of the cam ring 4 in an area close to the four bolts (each bolt hole 16).

  Each concave portion 42 is formed in a half-moon shape, and is arranged in a region facing the cross-hatching portion 106 shown in FIG. 6 where the deformation amount of the cover 10 is relatively small. Each recess 42 is formed symmetrically about the rotation center axis of the rotor 6.

  In this case as well, the cover 10 is deformed by the driving force of the pressure loading mechanism and the working fluid pressure when the vane pump is operated. However, the cover 10 corresponds to a relatively small deformation amount of a portion fastened to the body 1 by each bolt. Thus, by forming the four concave portions 42 in regions close to the four bolts, there is a portion where the surface pressure is locally increased between the convex portion 41 of the cam ring 4 and the side surface of the cover 10 when the vane pump is operated. Occurrence is suppressed, the gap between the cover 10 and the cam ring 4 is reduced, and the gap between the cover 10 and the rotor 6 is reduced. The working fluid that becomes high pressure in the vane chamber leaks into the body 1 through these gaps. This can reduce the volumetric efficiency of the vane pump.

  Next, another embodiment shown in FIG. 9 will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  In the present embodiment, as shown in FIG. 9 (a), two concave portions 42 are formed in the side surface of the cam ring 4 in a region close to the two bolts (each bolt hole 16), and in FIG. As shown in (b), the opening 12a of the suction passage 12 of the cover 10 is formed in a region close to the two bolts (each bolt hole 16).

  Each concave portion 42 is formed in a substantially half-moon shape, and is disposed in a region facing the cross hatching portion 106 shown in FIG. 6 where the deformation amount of the cover 10 is relatively small and away from the suction passage 12.

  The suction passage 12 is formed in a substantially V-shaped groove shape, and the opening 12a is disposed in the cross hatching portion 106 shown in FIG. 6 where the deformation amount of the cover 10 is relatively small.

  In this case as well, the cover 10 is deformed by the driving force of the pressure loading mechanism and the working fluid pressure when the vane pump is operated. However, the cover 10 corresponds to a relatively small deformation amount of a portion fastened to the body 1 by each bolt. The two recesses 42 are respectively formed in the region close to the two bolts, and the opening 12a of the suction passage 12 is formed in the region close to the two bolts, so that the cam ring 4 can be operated when the vane pump is operated. It is suppressed that the part where the surface pressure increases locally between the side surface and the cover 10, and the convex portion 41 has a sufficient surface pressure on the cover 10 at the hatched portions 105 a and 105 b shown in FIG. 9B. The working fluid that is in contact with the high pressure in the vane chamber is prevented from leaking into the body 1 through the gap between the cover 10 and the cam ring 4. It is to increase the volumetric efficiency of the pump.

  Next, another embodiment shown in FIG. 10 will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  In this embodiment, as shown in FIGS. 10A and 10B, the side surface 10a of the cover 10 facing the cam ring 4 corresponds to the cover 10 that is deformed by the driving force of the pressure loading mechanism and the working fluid pressure. Thus, an annular recess 52 is formed, and a protrusion 51 is formed inside the recess 52 to reduce the gap between the cam ring 4 and the cover 10.

  As shown in FIG. 10A, the recess 52 is formed in the region of the cross-hatching portion 106 shown in FIG. 6 where the deformation amount of the cover 10 is relatively small, and the protrusion 51 is the deformation amount of the cover 10. 6 is formed over the cross-hatched portion 105 shown in FIG.

  As shown in FIG. 10B, the convex portion 51 and the concave portion 52 are formed in a planar shape orthogonal to the rotation axis direction of the rotor 6. The recess 52 has a step 53 with a predetermined value d with respect to the protrusion 51.

  Also in this case, the cover 10 is deformed by the driving force of the pressure loading mechanism and the working fluid pressure when the vane pump is operated, but the convex portion 51 formed on the side surface 10a of the cover 10 bulges corresponding to the deformation of the cover 10. Therefore, the surface pressure of the convex portion 51 against the cam ring 4 is uniformly distributed when the vane pump is operated. Accordingly, there is no portion where the surface pressure is locally increased between the side surface of the cam ring 4 and the side surface 10a of the cover 10 when the vane pump is operated, and the gap between the cover 10 and the cam ring 4 is reduced. The gap between the rotors 6 is reduced, and the working fluid that becomes high pressure in the vane chamber is prevented from leaking into the body 1 through these gaps, and the volumetric efficiency of the vane pump can be increased.

  Note that the recess 52 is not necessarily formed in an annular shape, and may be formed independently in a region close to the four bolts (each bolt hole 16) as in the recess 42 shown in FIG.

  Hereinafter, the vane pump shown in FIGS. 11 to 14 will be described in detail. In addition, the same code | symbol is attached | subjected to the site | part corresponding to the vane pump shown to the said FIGS.

  FIG. 11 shows the result of analyzing the deformation distribution of the cover 10 by the driving force of the pressure loading mechanism and the working fluid pressure by the finite element method.

  FIG. 12 is a diagram schematically showing the deformation distribution of the cover 10 based on the analysis result of FIG. The deformation amount of the cover 10 increases in the order of the hatching area 101, the hatching area 102, and the hatching area 103 shown in FIG.

  11 and 12, the deformation amount of the cover 10 is the largest at the central portion facing the rotor 6, and decreases as the distance from the central portion increases, and the portion near the bolt hole 16 in the circumferential direction of the cam ring 4 is the bolt hole. As can be seen from FIG.

  FIG. 13 is a cam ring layout diagram showing the regions where the cam ring 4 faces the cover 10 as cam ring joints 100a and 100b.

  FIG. 14 shows the deformation distribution diagram of FIG. 12 and the cam ring arrangement diagram of FIG. The cross-hatching portions 105a and 105b are regions that overlap with the hatching region 102 where the deformation amount of the cover 10 is medium at the cam ring joint portions 100a and 100b. The cross-hatching portion 106 is a region overlapping the hatching region 102 where the deformation amount of the cover 10 is relatively small in the cam ring joint portions 100a and 100b.

  Since the cross hatching portion 106 has a smaller deformation amount than the cross hatching portion 105, the cam ring 4 and the cover 10 are mainly joined by the cross hatching portion 106, while the cross hatching portion 105 may have a gap. When a gap is generated in the cross hatching portion 105, the working fluid having a high pressure in the vane chamber leaks into the body 1 through the gap, and the volumetric efficiency of the vane pump is lowered.

  Therefore, the present invention forms a concave groove around the contact portion of the cover 10 with respect to the cam ring 4, and receives the driving force and the working fluid pressure of the pressure loading mechanism when the vane pump is operated, so that the contact surface 60a, The gist is that the configuration is such that the deformation of the 60b is suppressed and the gap between the cover 10 and the cam ring 4 is reduced.

  Hereinafter, the embodiment shown in FIG. 15 will be described with respect to a specific example of the vane pump.

  In the present embodiment, as shown in FIG. 15, grooves 17 and 61 surrounding contact surfaces 60a and 60b that contact the cam ring 4 are formed on the side surface 10a of the cover 10 that faces the cam ring 4, respectively, and the pressure is applied when the vane pump is operated. The contact surfaces 60a and 60b are prevented from being deformed by receiving the driving force of the loading mechanism and the working fluid pressure.

  The V-shaped groove 17 defines a suction passage 12 that is bifurcated. The groove 17 is disposed in a region where the cross hatching portion 101 and the cam ring 4 are overlapped as shown in FIG.

  The groove 61 is formed in a region indicated by hatching in FIG. The groove 61 is disposed in the cross hatching portion 106 shown in FIG. 14 where the cam ring 4 and the cross hatching portion 101 shown in FIG.

  The outer peripheral edge 61 b of the groove 61 is formed in an arc shape along the outer peripheral edge of the cam ring 4.

  The inner peripheral edge 61 a of the groove 61 is formed symmetrically with respect to the inner peripheral edge 17 a of the groove 17 and the rotation center axis of the rotor 6.

  The grooves 17 and 61 are formed symmetrically about the center line X including the rotation center axis of the rotor 6. The contact surfaces 60a and 60b of the cover 10 are formed symmetrically about the rotation center axis.

  The inner peripheral edge portion 61a of the groove 61 and the inner peripheral edge portion 17a of the groove 17 each have a portion extending linearly facing the four bolts (each bolt hole 16).

  The contours and groove depths of the grooves 61 and 17 are arbitrarily set according to the required rigidity distribution of the cover 10.

  Next, the operation and effect will be described.

  As the rotor 6 rotates, the vane chamber defined between the vanes 7 expands in the suction region S, sucks the working fluid from the suction passage 12, and contracts in the discharge region T to transfer the working fluid to the discharge passage 14. Discharge.

  The pressure loading mechanism drives the side plate 3 in the direction of the rotation axis of the rotor 6 by the working fluid pressure guided to the discharge passage 14 and presses the side plate 3 against the cover 10 via the rotor 6 and the cam ring 4. Since the central portion of the cover 10 is deformed in a concave shape with respect to the four bolt fastening portions by the working fluid pressure, the gap between the cover 10 and the cam ring 4 and between the cover 10 and the rotor 6 may partially increase. .

  In order to cope with this, in the present embodiment, the groove 10 is formed on the side surface 10a facing the cam ring 4 of the cover 10 so as to surround the contact surfaces 60a and 60b contacting the cam ring 4, respectively. When the vane pump is operated, the portions where the grooves 17 and 61 are opened by receiving the driving force and the working fluid pressure of the pressure loading mechanism are pulled and deformed by the four bolt fastening portions, thereby having the contact surfaces 60a and 60b. The deformation of the island-like raised portion is suppressed, and the contact surfaces 60a and 60b are prevented from being deformed. For this reason, when the vane pump is operated, there is no portion where the surface pressure is locally increased between the side surface 10a of the cam ring 4 and the side surface of the cover 10, and the gap between the cover 10 and the cam ring 4 can be reduced. And by suppressing a deformation | transformation to the center part of the cover 10, the clearance gap between the cover 10 and the rotor 6 can be reduced. Thereby, it is possible to prevent the working fluid having a high pressure in the vane chamber from leaking into the body 1 through the gap between the cover 10 and the cam ring 4 and between the cover 10 and the rotor 6, thereby increasing the volumetric efficiency of the vane pump.

  The inner peripheral edge portion 61a of the groove 61 and the inner peripheral edge portion 17a of the groove 17 have portions extending linearly facing the four bolts, so that the driving force and the working fluid pressure of the pressure loading mechanism when the vane pump is operated. Therefore, it is possible to effectively suppress deformation of the island-like raised portions having the contact surfaces 60a and 60b by being pulled by the four bolt fastening portions, and the gap between the cover 10 and the cam ring 4 can be reduced. .

  The inner peripheral edge portion 61a of the groove 61 and the inner peripheral edge portion 17a of the groove 17 are formed symmetrically with respect to the rotation center axis of the rotor 6 so that the portion having the contact surfaces 60a and 60b and protruding in an island shape is the rotor. 6, the rigidity of the contact surfaces 60a and 60b is enhanced in a balanced manner with respect to the load received from the rotor 6 and the cam ring 4, and the deformation of the contact surfaces 60a and 60b is effectively suppressed, A gap between the cover 10 and the cam ring 4 can be reduced.

  As another embodiment, as shown in FIG. 16, the resin material 62 is filled in the groove 61 of the metal cover 10, and the contact surface 62 a made of the resin material 62 is brought into contact with the cam ring 4. The resin material 62 is formed in a region indicated by cross hatching in FIG.

  In this case, since the resin material 62 filling the groove 61 is significantly lower in rigidity than the metal cover 10, the resin material 62 has contact surfaces 60 a and 60 b in response to the driving force and working fluid pressure of the pressure loading mechanism when the vane pump is operated. It is possible to reduce the gap between the cover 10 and the cam ring 4 without impairing the action of preventing the island-like raised portion from being deformed by being pulled by the respective bolt fastening portions via the grooves 61.

  When the contact surface 62 a made of the resin material 62 contacts the cam ring 4, the sealing performance between the cover 10 and the cam ring 4 can be improved.

  Since the resin material 62 defines the end of the suction passage 12, the flow of the working fluid in the suction passage 12 can be made smooth, and the operation efficiency of the vane pump can be increased.

  As another embodiment, as shown in FIG. 17, a bank portion 63 that defines the suction passage 12 is formed at both ends of the groove 61 of the metal cover 10.

  In this case, since the bank portion 63 defines the end of the suction passage 12, the flow of the working fluid in the suction passage 12 is smoothed, and the operation efficiency of the vane pump can be increased. The bank portion 63 is formed in a region shown with cross hatching in FIG.

  The bank portion 63 is made of a material having a lower hardness than the cover 10 such as resin. In this case, it becomes possible to improve the sealing performance between the cover 10 and the cam ring 4 by bringing the surface of the bank portion 63 into contact with the cam ring 4.

  In addition, when the bank part 63 is formed of a material having a hardness equal to or higher than that of the cover 10 such as a resin, the surface of the bank part 63 is formed in a concave shape with respect to the contact surface 60 b of the cover 10. . Thereby, it is possible to suppress the contact surface 60b from being deformed by the bank portion 63, and to reduce the gap between the cover 10 and the cam ring 4.

  In each of the above embodiments, the number of bolts that fasten the cover 10 to the body 1 is four. However, the number of bolts is not limited to this, and the number of bolts is arbitrarily set.

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

  The vane pump of the present invention is used for, for example, a fluid pressure source of a power steering device, another fluid pressure source, and the like.

Sectional drawing of the vane pump to which this invention is applied. The side view of a vane pump. The figure which similarly shows the result of having analyzed the distribution of the deformation amount of a cover. Similarly, a shape distribution diagram schematically showing the distribution of deformation of the cover. Similarly, cam ring layout for the body. The figure which overlapped and showed the amount-of-deformation distribution diagram and cam ring arrangement drawing similarly. The side view and top view of a cam ring which show embodiment of this invention. The side view of the cam ring which shows other embodiment. The side view of the cam ring and cover which show other embodiment. The side view and sectional drawing of the cover which show other embodiment. The figure which similarly shows the result of having analyzed the distribution of the deformation amount of a cover. Similarly, a shape distribution diagram schematically showing the distribution of deformation of the cover. Similarly, cam ring layout for the body. The figure which overlapped and showed the amount-of-deformation distribution diagram and cam ring arrangement drawing similarly. The side view of the cover which shows embodiment of this invention. The side view of the cover which shows other embodiment. The side view of the cover which shows other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 3 Side plate 4 Cam ring 6 Rotor 7 Vane 10 Cover 10a Cover side surface 17 Groove 41 Convex part 42 Concave part 51 Convex part 52 Concave part 60a, 60b Contact surface 61 Groove 62 Resin material 63 Bank part

Claims (10)

A rotor rotatably housed in the body, a plurality of vanes projecting slidably from the rotating rotor, a cam ring defining a vane chamber by sliding the tip of each vane, and each vane A side plate defining the vane chamber by slidingly contacting one side end; a cover defining the vane chamber by sliding the other side end of each vane; and the body and the cover A suction passage that allows the working fluid to flow into the vane chamber that expands as the rotor rotates, and a discharge passage that causes the working fluid to flow out of the vane chamber that contracts as the rotor rotates. In a vane pump including a pressure loading mechanism that presses the side plate and the cover against the rotor by a working fluid pressure guided to the discharge passage.
A convex portion is formed on at least one of the side surface of the cam ring and the side surface of the cover that face each other, and is deformed by receiving the driving force and working fluid pressure of the pressure loading mechanism during operation. A vane pump characterized in that the gap between the two is reduced through the convex portion.   The side surface of the cam ring is formed with the convex portion extending along the inner peripheral edge of the cam ring and the concave portion extending along the cover that is deformed by receiving the driving force and the working fluid pressure of the pressure loading mechanism. The vane pump according to claim 1.   The vane pump according to claim 2, wherein the recess is formed in a region close to the bolts.   The opening portion of the suction passage with respect to the side surface of the cover is formed in a region adjacent to each bolt along the cover that is deformed by receiving the driving force and working fluid pressure of the pressure loading mechanism. The vane pump according to 1 or 2.   The vane pump according to claim 1, wherein a concave portion extending in an annular shape is formed on a side surface of the cover, and the convex portion is formed inside the concave portion. A rotor rotatably housed in the body, a plurality of vanes projecting slidably from the rotating rotor, a cam ring defining a vane chamber by sliding the tip of each vane, and each vane A side plate defining the vane chamber by slidingly contacting one side end; a cover defining the vane chamber by sliding the other side end of each vane; and the body and the cover A suction passage that allows the working fluid to flow into the vane chamber that expands as the rotor rotates, and a discharge passage that causes the working fluid to flow out of the vane chamber that contracts as the rotor rotates. In a vane pump including a pressure loading mechanism that presses the side plate and the cover against the rotor by a working fluid pressure guided to the discharge passage.
A vane pump characterized in that a groove surrounding a contact surface in contact with the cam ring is formed in the cover, and the deformation of the contact surface due to the driving force and working fluid pressure of the pressure loading mechanism is suppressed through the groove. .   3. The vane pump according to claim 2, wherein the inner peripheral edge of the groove is formed symmetrically with respect to the rotation center axis of the rotor.   The vane pump according to claim 7, wherein a portion extending linearly facing the bolts is formed at an inner peripheral edge of the groove.   The vane pump according to any one of claims 7 to 8, wherein the groove is filled with a resin material, and a contact surface made of the resin material is brought into contact with the cam ring.   The vane pump according to any one of claims 7 to 9, wherein a bank portion that defines the suction passage is formed in the groove.