JP2018135828A - Variable displacement oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress degradation of pump efficiency of a variable displacement oil pump.SOLUTION: In a variable displacement oil pump 1, an oil introduction groove 2f is formed on a rear end side in a rotor rotating direction, of a discharge port 19 where an accommodation ratio of a vane 6 in a slit 5a of a rotor 5 is increased. The oil introduction groove 2f is linearly extended from a terminal end portion 19b of the discharge port 19 to a position in a region A between an inner peripheral face of a circumferential wall 23b of a circular recessed portion 23 and an outer peripheral face of a ring member 9. A terminal end 29 of the oil introduction groove 2f is positioned at a rotation upstream side of the vane 6 with respect to a starting end 28. At the rear end side in the rotor rotating direction, of the discharge port 19, an angle θ is formed by the vane 6 and the oil introduction groove 2f. The angle θ is an acute angle.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a variable displacement oil pump.

  As a variable displacement oil pump, for example, a variable displacement oil pump described in Patent Document 1 below is known.

  In the variable displacement oil pump described in Patent Document 1, the lateral groove of the bearing oil supply groove extends from the discharge port to the bearing hole for the drive shaft.

Japanese Patent No. 5059799

  In Patent Document 1, the vane is inclined with respect to the drive shaft by the discharge pressure from the discharge port, and the corner portion of the vane and the edge portion of the lateral groove may interfere with each other. As a result, there is a problem that friction increases and the pump efficiency of the variable displacement oil pump decreases.

  The present invention has been devised in view of conventional circumstances, and an object of the present invention is to provide a variable displacement oil pump that suppresses a decrease in pump efficiency.

  According to the present invention, in one aspect thereof, the oil introduction groove extends from the discharge port to a corresponding position between the circular recess of the rotor and the inner end of the passing vane.

  According to the present invention, the oil introduction groove can suppress a decrease in pump efficiency of the variable displacement oil pump.

1 is an exploded perspective view of a variable displacement oil pump according to a first embodiment. It is a front view of the housing main body of a 1st Example. It is sectional drawing of the housing main body cut | disconnected along line AA of FIG. FIG. 3 is a cross-sectional view of the housing body cut along line BB in FIG. 2. It is an assembly drawing of the variable displacement oil pump with the cover member removed. FIG. 6 is a partially enlarged view of the variable displacement oil pump on the rear end side in the rotor rotation direction of the discharge port of FIG. 5. It is a perspective view of a ring member. It is sectional drawing of the variable displacement oil pump cut | disconnected along line CC of FIG. It is a front view of a cover member. It is sectional drawing of the cover member cut | disconnected along line DD of FIG. It is sectional drawing of the housing main body etc. which showed the lateral groove of the bearing oil supply groove | channel in the prior art, and its periphery. It is sectional drawing of the housing main body etc. which showed the oil introduction groove | channel in the 1st Example, and its circumference | surroundings. It is a front view of the housing main body which has the oil introduction groove | channel of the 2nd Example. It is an assembly drawing of the variable displacement type oil pump of the 2nd example.

Hereinafter, an embodiment of a variable displacement oil pump according to the present invention will be described with reference to the drawings.
[First embodiment]
(Configuration of variable displacement oil pump)
FIG. 1 is an exploded perspective view of a variable displacement oil pump 1 provided in a cylinder block or the like of an internal combustion engine (not shown).

  The variable displacement oil pump 1 includes a housing body 2, a cover member 3, a drive shaft 4, a rotor 5, seven vanes 6, a cam ring 7, a coil spring 8, and a pair of ring members 9, 9. The first and second sealing means 10 and 11 and six fixing means 12 such as bolts are provided.

  The housing body 2 is integrally formed of a metal material, for example, an aluminum alloy material, and is formed in a U-shaped cross section so that one end side is open and has a cylindrical pump housing chamber 13 inside. The housing body 2 has a first bearing hole 2 a (see FIG. 2) that rotatably supports one end of the drive shaft 4 at the center position of the bottom surface 13 a of the pump housing chamber 13. The housing body 2 is formed with an annular continuous flat mounting surface 2 b on the outer peripheral side of the opening of the pump housing chamber 13. On the mounting surface 2b of the housing body 2, six fixing means through holes 2c into which the respective fixing means 12 are inserted are formed.

  The cover member 3 is formed of a metal material, for example, an aluminum alloy material, like the housing body 2, and is used so as to close the opening of the housing body 2. The cover member 3 has a flat plate shape and has an outer shape corresponding to the outer shape of the housing body 2. The cover member 3 is formed with a second bearing hole 3 a that rotatably supports the other end of the drive shaft 4 at a position corresponding to the first bearing hole 2 a of the housing body 2. Further, six fixing means through holes 3 b into which the fixing means 12 are inserted are formed in the outer peripheral portion of the cover member 3 at positions corresponding to the six fixing means through holes 2 c of the housing body 2.

  The housing body 2 and the cover member 3 constitute a housing that partitions the pump housing chamber 13.

  The variable displacement oil pump 1 has a dual-support structure in which the drive shaft 4 is supported by the first bearing hole 2 a of the housing body 2 and the second bearing hole 3 a of the cover member 3. The cantilever structure may be supported only by the first bearing hole 2a. In this case, it is not necessary to form the second bearing hole 3a of the cover member 3.

  The drive shaft 4 passes through the center of the pump housing chamber 13 and is rotatably supported by the housing, and is driven to rotate by a crankshaft (not shown).

  The rotor 5 has a cylindrical shape and is rotatably accommodated in the pump accommodating chamber 13. The central portion of the rotor 5 is coupled to the drive shaft 4. The rotor 5 is formed with seven slits 5a extending radially outward from the inner center side of the rotor 5 in the radial direction. Further, on both side surfaces of the rotor 5 (only one side surface is shown in FIG. 1), circular recesses 23 to be described later that are recessed in a circle around the drive shaft 4 are formed.

  The vane 6 is formed in a thin plate shape with metal and is accommodated in the slit 5a of the rotor 5 so as to be able to appear and retract. In a state where the vane 6 is accommodated in the slit 5a, a slight gap is formed between the vane 6 and the slit 5a. The vane 6 has a distal end surface slidably in contact with the inner peripheral surface of the cam ring 7, and an inner end surface of the base end portion slidably in contact with the outer peripheral surface of the ring member 9.

  In addition, the drive shaft 4, the rotor 5, and each vane 6 comprise the pump element.

  The cam ring 7 is integrally formed in a cylindrical shape with a sintered metal.

  The coil spring 8 is accommodated in the housing body 2 and constantly urges the cam ring 7 in a direction in which the eccentric amount of the cam ring 7 with respect to the rotation center of the rotor 5 increases.

  The ring member 9 has an outer diameter smaller than the outer diameter of the rotor 5, and is slidably disposed in a circular recess 23 provided in the rotor 5.

  The first and second sealing means 10 and 11 are attached to the cam ring 7 and partition the cam ring 7 and the housing body 2. As a result, first and second control oil chambers 24 and 25 described later are formed between the outer peripheral surface of the cam ring 7 and the inner peripheral surface of the housing body 2. The first and second sealing means 10 and 11 include a sealing member 15 and an elastic member 16, respectively.

  FIG. 2 shows a front view of the housing body 2 as viewed in the axial direction of the variable displacement oil pump 1 from the left side of FIG.

  As shown in FIG. 2, a first bearing hole 2 a that rotatably supports one end of the drive shaft 4 passes through a central position of the bottom surface 13 a of the pump housing chamber 13 of the housing body 2. Further, as shown in FIG. 2, a rod-like pivot pin that supports the cam ring 7 in a swingable manner at a position serving as a swing fulcrum of the cam on the inner peripheral wall of the pump housing chamber 13 serving as the inner peripheral surface of the housing body 2. An arc-shaped support groove 2d for supporting 17 (see FIG. 5) is formed.

  Here, for convenience of explanation, a straight line connecting the center O of the first bearing hole 2a and the center 17a of the pivot pin 17 is defined as a “cam ring reference line M”.

  First and second seal contact surfaces 13b and 13c are formed on both sides of the cam ring reference line M on the inner peripheral wall of the pump storage chamber 13, and the outer peripheral portion of the cam ring 7 is formed on the seal contact surfaces 13b and 13c. The seal members 15, 15 provided on the slidably contact with each other. As shown in FIG. 2, the first seal contact surface 13 b is an arc surface formed by a predetermined radius R <b> 1 from the center 17 a of the pivot pin 17. On the other hand, as shown in FIG. 2, the second seal contact surface 13c is an arcuate surface formed by a predetermined radius R2 smaller than the radius R1 from the center 17a of the pivot pin 17. The radii R <b> 1 and R <b> 2 are set to circumferential lengths in which the seal members 15 and 15 can always slidably contact in the eccentric swing range of the cam ring 7.

  In addition, on the bottom surface 13a of the pump storage chamber 13, as shown in FIG. 2, there is a suction port 18 that is an arc concave suction portion and a discharge that is also an arc concave discharge portion in the outer peripheral area of the first bearing hole 2a. The port 19 is cut away so as to face the first bearing hole 2a. The suction port 18 is located on the side of the bottom surface 13a opposite to the support groove 2d, while the discharge port 19 is located on the support groove 2d side. The suction port 18 opens to a region (suction region) where the internal volume of a pump chamber 20 (see FIG. 5), which will be described later, increases with the pumping action of the pump element. The suction port 18 is integrally formed with the suction port 18 so that the suction port 18 bulges toward the spring accommodating chamber 21 described later at an intermediate position in the circumferential direction. A suction hole 18a having a circular cross section that is open to the outside through the bottom wall of the housing body 2 is provided at the boundary between the introduction portion 22 and the suction port 18. As a result, the lubricating oil stored in the oil pan of the internal combustion engine (not shown) causes each pump described later in the suction area to pass through the suction hole 18a and the suction port 18 based on the negative pressure generated by the pumping action of the pump element. Inhaled into chamber 20.

  The discharge port 19 opens to a region (discharge region) where the internal volume of the pump chamber 20 decreases with the pumping action of the pump element.

  In the discharge port 19, a discharge hole 19 a having a circular cross section communicating with the internal combustion engine (not shown) passes through the bottom wall of the housing body 2 at the upper position in FIG. 2.

  In the housing body 2, a spring accommodating chamber 21 for accommodating the coil spring 8 is provided at a position adjacent to the suction hole 18a. As shown in FIG. 2, a stopper surface 21 a is formed on the wall surface of the spring accommodating chamber 21 by slightly protruding toward the spring accommodating chamber 21, and the stopper surface 21 a An arm portion 7a (described later) of the cam ring 7 biased by the coil spring 8 is received.

  Furthermore, an oil retaining groove 2e that retains oil and lubricates the drive shaft 4 is formed on the inner peripheral surface of the first bearing hole 2a. In the present embodiment, as shown in FIG. 2, the oil retaining groove 2e is formed above the cam ring reference line M and at a position orthogonal to the cam ring reference line M on the inner peripheral surface of the first bearing hole 2a. ing.

  An oil introduction groove 2 f for introducing oil from the discharge port 19 to a circular recess 23 described later of the rotor 5 is formed on the bottom surface 13 a of the pump storage chamber 13.

  FIG. 3 shows a cross-sectional view of the housing body 2 taken along line AA in FIG.

  As shown in FIG. 3, the oil retaining groove 2 e extends in the thickness direction of the bottom wall from the bottom surface 13 a of the pump housing chamber 13 so as to exceed 1/2 of the thickness of the bottom wall of the housing body 2.

  FIG. 4 shows a cross-sectional view of the housing body 2 taken along line BB in FIG.

  As shown in FIG. 4, an oil introduction groove 2 f having a trapezoidal cross section is formed on the bottom surface 13 a of the pump housing chamber 13. The oil introduction groove 2 f allows the discharge port 19 and the circular recess 23 to communicate with each other. The width W of the oil introduction groove 2f along the left-right direction in FIG. 4 is the widest on the bottom surface 13a side and becomes narrower as the distance from the bottom surface 13a increases. The width W of the oil introduction groove 2f is smaller than the thickness Tv of the vane 6 indicated by a broken line in FIG. The oil introduction groove 2f may have a square cross section or a rectangular cross section.

  Here, for convenience of explanation, the direction along the drive shaft 4 is defined as the “axial direction” of the variable displacement oil pump 1, and the direction orthogonal to the axial direction is defined as the “radial direction” of the variable displacement oil pump 1. To do.

  FIG. 5 is an assembly diagram of the variable displacement oil pump 1 with the cover member 3 removed.

  As shown in FIG. 5, the cam ring 7 is supported in the pump housing chamber 13 of the housing body 2 so as to be swingable about a pivot pin 17. Further, a rotor 5 coupled to the drive shaft 4 is disposed in the cam ring 7.

  On both side surfaces of the rotor 5, circular recesses 23 that are recessed in a circle around the drive shaft 4 are formed in the axial direction, and the circular recesses 23 are bottom walls 23 a parallel to the bottom surface 13 a of the pump housing chamber 13. And a peripheral wall 23b surrounding the bottom wall 23a in a ring shape. In the circular recess 23, the ring member 9 having an outer diameter smaller than the inner diameter of the peripheral wall 23b of the circular recess 23 is accommodated. Therefore, a radial gap 32 is formed between the inner peripheral surface of the peripheral wall 23 b of the circular recess 23 and the outer peripheral surface of the ring member 9.

  Further, the vane 6 is disposed so as to be able to protrude and retract in a slit 5a formed in the rotor 5, the distal end surface slidably contacts the inner peripheral surface of the cam ring 7, and the inner end surface of the base end portion is a ring. The outer peripheral surface of the member 9 is slidably contacted.

  In the variable displacement oil pump 1 configured as described above, the outer peripheral surface of the rotor 5, the inner surfaces of the adjacent vanes 6, 6, the inner peripheral surface of the cam ring 7, and the pump housing chamber 13 of the housing body 2. The pump chamber 20 is liquid-tightly defined by the bottom surface 13 a and the inner peripheral surface of the cover member 3.

  A back pressure chamber 5 b having a circular cross section for introducing the discharge oil discharged to the discharge port 19 is formed at the inner base end of each slit 5 a of the rotor 5. The back pressure chamber 5 b opens in the circular recess 23. Oil from a second control oil chamber 25 described later flows into the back pressure chamber 5b through the discharge port 19, the oil introduction groove 2f, and the circular recess 23. Therefore, each vane 6 accommodated in the slit 5a of the rotor 5 so as to be able to appear and retract is pushed outward by the centrifugal force accompanying the rotation of the rotor 5 and the hydraulic pressure of the back pressure chamber 5b.

  In addition, as described above, the vane 6 has the inner end surface of the base end portion slidably contacting the outer peripheral surface of the ring member 9, whereby the engine speed is low, and the centrifugal force and the back pressure chamber are reduced. Even when the hydraulic pressure of 5b is small, the vane 6 can slide on the inner peripheral surface of the cam ring 7.

  As shown in FIG. 5, an arc-shaped concave pivot groove 7b that supports the pivot pin 17 in cooperation with the support groove 2d is provided along the axial direction at a position that becomes the pivot point of the cam on the outer peripheral portion of the cam ring 7. Is formed. The pivot pin 17 supported by the pivot groove 7b and the support groove 2d serves as an eccentric rocking fulcrum of the cam ring 7.

  Further, the cam ring 7 includes an arm portion 7a that is linked to the coil spring 8 at a position opposite to the pivot groove 7b across the center of the cam ring 7. The arm portion 7 a protrudes in the radial direction from the outer peripheral portion of the cam ring 7. The arm 7a is formed with an arc-shaped pressing protrusion 7c on one side of the moving (turning) direction, and this pressing protrusion 7c is always in contact with the tip of the coil spring 8. Thus, the arm portion 7a and the coil spring 8 are linked.

  Further, as shown in FIG. 5, the outer periphery of the cam ring 7 has a triangular cross section having first and second seal surfaces at positions facing the first and second seal contact surfaces 13b and 13c. 1 and 2nd seal holding | maintenance parts 7d and 7e each protrude. Here, the first and second seal surfaces are predetermined slightly smaller than the radii R1 and R2 (see FIG. 2) constituting the seal contact surfaces 13b and 13c corresponding to the center 17a of the pivot pin 17, respectively. It is constituted by the radius. A minute clearance is formed between each seal surface and each seal contact surface 13b, 13c. Further, first and second seal holding grooves 7f and 7g having a U-shaped cross section are formed along the axial direction of the cam ring 7 on the seal surfaces of the seal holding portions 7d and 7e, respectively. In the first and second seal holding grooves 7f and 7g, the first and second seal means 10 and 11 that are in contact with the first and second seal contact surfaces 13b and 13c when the cam ring 7 is eccentrically swung are respectively held. Yes.

  The first and second sealing means 10 and 11 include a sealing member 15 and an elastic member 16, respectively. The seal member 15 is formed in an elongated plate shape along the axial direction by using, for example, a fluorine-based resin material having low friction characteristics. In addition, the elastic member 16 is formed in an elongated cylindrical shape along the axial direction by rubber, for example. The elastic member 16 is provided between the seal member 15 and the bottom of the seal holding grooves 7f and 7g, and presses the seal member 15 against the seal contact surfaces 13b and 13c by the elastic force of the elastic member 16. Thereby, the liquid-tightness of the 1st, 2nd control oil chambers 24 and 25 mentioned later is always ensured.

  A spring housing chamber 21 is provided in the housing body 2 so as to communicate with the pump housing chamber 13 through a suction hole 18a formed at a position opposite to the support groove 2d. A coil spring 8 is accommodated in the housing.

  The coil spring 8 is elastic with a predetermined set load Ws between the pressing projection 7c at the tip of the arm portion 7a extending into the spring accommodating chamber 21 and the bottom surface of the spring accommodating chamber 21 so as to cross the suction hole 18a. Is held in.

  Therefore, the coil spring 8 always urges the cam ring 7 in the direction in which the amount of eccentricity increases (clockwise in FIG. 5) with the elastic force based on the set load Ws via the arm portion 7a. As a result, when the cam ring 7 is not in operation, the outer surface of the arm portion 7 a is pressed against the stopper surface 21 a formed on the wall surface of the spring accommodating chamber 21 by the spring force of the coil spring 8. It is held at a position where the amount of eccentricity is maximized.

  As shown in FIG. 5, the outer peripheral area of the cam ring 7 on the pivot groove 7 b side serving as the pump discharge side is provided between the inner peripheral surface of the housing body 2 and the outer peripheral surface of the cam ring 7. The first control oil chamber 24 and the second control oil chamber 25 are demarcated by the pins 17 on both sides of the pivot groove 7b.

  The first control oil chamber 24 is supplied with the pump discharge pressure discharged to the discharge port 19. The first pressure receiving surface 26 constituted by the outer peripheral surface of the cam ring 7 facing the first control oil chamber 24 receives the hydraulic pressure from the discharge port 19 against the urging force of the coil spring 8, and the eccentric amount of the cam ring 7. Oscillating force (moving force) is applied in the direction of decreasing (counterclockwise in FIG. 5).

  That is, the first control oil chamber 24 always operates the cam ring 7 in the direction in which the center of the cam ring 7 approaches the center of rotation of the rotor 5 via the first pressure receiving surface 26, that is, in the direction in which the amount of eccentricity decreases. The cam ring 7 is used for controlling the amount of movement in the concentric direction.

  On the other hand, the discharge pressure discharged from the discharge hole 19a is appropriately introduced into the second control oil chamber 25 by the on / off operation of an electromagnetic switching valve (not shown). The electromagnetic switching valve operates according to the operating state of the engine based on an exciting current from a control unit that controls the internal combustion engine.

  Further, a second pressure receiving surface 27 is formed on the outer peripheral surface of the cam ring 7 facing the second control oil chamber 25, and the biasing force of the coil spring 8 is applied by applying a discharge pressure to the second pressure receiving surface 27. A force acting in the direction of assisting is generated. As a result, a swinging force (moving force) is applied to the cam ring 7 in a direction that increases the amount of eccentricity (clockwise in FIG. 5).

  Here, as shown in FIG. 5, the pressure receiving area of the first pressure receiving surface 26 is larger than the pressure receiving area of the second pressure receiving surface 27. The biasing force in the eccentric direction of the cam ring 7 due to the biasing force based on the internal pressure of the second control oil chamber 25 and the biasing force of the coil spring 8 and the biasing force based on the internal pressure of the first control oil chamber 24 are predetermined. It is configured to balance with relationships. Note that the hydraulic pressure in the second control oil chamber 25 assists the biasing force of the coil spring 8 as described above.

  6 shows a partially enlarged view of the variable displacement oil pump 1 on the rear end side in the rotor rotation direction of the discharge port 19 of FIG. FIG. 6 shows the variable displacement oil pump 1 when the vane 6 starts to pass through the oil introduction groove 2f. In FIG. 6, the oil introduction groove 2f is indicated by a broken line, and the discharge port 19 is indicated by a two-dot chain line.

  As shown in FIG. 6, the oil introduction groove 2 f is provided on the rear end side in the rotor rotation direction of the discharge port 19 where the proportion of the vane 6 accommodated in the slit 5 a of the rotor 5 increases. The oil introduction groove 2 f linearly extends from the rear end side in the rotor rotation direction of the discharge port 19 to a position between the inner peripheral surface of the peripheral wall 23 b of the circular recess 23 and the outer peripheral surface of the ring member 9. That is, the start end 28 of the oil introduction groove 2 f is located at the end portion 19 b of the discharge port 19, and the end 29 of the oil introduction groove 2 f is on the upstream side of the rotation of the vane 6 with respect to the start end 28. It extends to a position in the region A between the inner end surface of the end portion and the inner peripheral surface of the peripheral wall 23 b of the circular recess 23. As shown in FIG. 6, an angle θ is formed by the vane 6 and the oil introduction groove 2f. The angle θ is an acute angle.

  FIG. 7 shows a perspective view of the ring member 9.

  The ring member 9 includes a groove 9b that extends in the radial direction of the ring member 9 from the inner peripheral surface to the outer peripheral surface of the ring member 9 on one side surface 9a. As shown in FIG. 7, the groove 9b has a U-shaped cross section.

  FIG. 8 shows a cross-sectional view of the variable displacement oil pump 1 cut along line CC in FIG.

  As shown in FIG. 8, a circular recess 23 formed on one side surface of the rotor 5 (right side surface in FIG. 8) opens toward the bottom surface 13 a of the pump storage chamber 13, while the other side of the rotor 5 A circular concave portion 23 formed on the side surface of the opening is open on the side opposite to the bottom surface 13a, that is, on the cover member 3 side. The ring member 9 on the bottom surface 13a side of the pump housing chamber 13 is disposed in the circular recess 23 in such a direction that the groove 9b opens toward the bottom surface 13a, while the groove of the ring member 9 on the cover member 3 side. 9 b is arranged in the circular recess 23 in a direction opening toward the cover member 3. Note that the ring members 9 and 9 on the bottom surface 13a side and the cover member 3 side of the housing body 2 may be disposed in the circular recesses 23 so as to open toward the bottom walls 23a.

  Further, as shown in FIG. 8, the depth D of the circular recess 23 is formed to be larger than the thickness Tr of the ring member 9. Therefore, on the bottom surface 13 a side of the pump housing chamber 13, an axial gap 34 is formed between one side surface 9 a and the bottom surface 13 a of the ring member 9. On the other hand, on the cover member 3 side, an axial gap 34 is formed between one side surface 9a of the ring member 9 and the back surface 3d of the cover member 3 (see FIG. 10).

  With such a configuration, in the variable displacement oil pump 1, oil from the oil introduction groove 2 f flows into the inner peripheral side of the ring member 9 through the axial gap 34 and the groove 9 b of the ring member 9, and the oil is retained. It flows into the groove 2e and the gap between the first bearing hole 2a and the drive shaft 4.

  FIG. 9 shows a front view of the cover member 3 as viewed in the axial direction of the variable displacement oil pump 1 from the left side of FIG.

  As described above, the cover member 3 is formed with the second bearing hole 3 a that rotatably supports the other end of the drive shaft 4 at a position corresponding to the first bearing hole 2 a of the housing body 2.

  FIG. 10 shows a cross-sectional view of the cover member 3 cut along the line DD in FIG.

  As shown in FIG. 10, the protrusion 3 e is formed in the cover member 3 by partially thickening the periphery of the second bearing hole 3 a of the plate-like cover member 3.

An oil retaining groove 3c that retains oil and lubricates the drive shaft 4 is formed on the inner peripheral surface of the second bearing hole 3a. As shown in FIG. 10, the oil retaining groove 3 c extends from the back surface 3 d (the right side surface in FIG. 10) of the cover member 3 to an extent exceeding 2/3 of the thickness of the cover member 3 including the convex portion 3 e. It extends in the thickness direction. The oil retaining groove 3c extends from the back surface 3d of the cover member 3 so as to taper in the thickness direction of the cover member 3, and a portion adjacent to the back surface 3d is formed in a stepped shape.
[Effect of the first embodiment]
FIG. 11 is a cross-sectional view of the housing main body 2 and the like showing the lateral groove 33 of the bearing oil supply groove and its periphery in the variable capacity oil pump of the prior art described in Patent Document 1.

  In the conventional variable displacement oil pump, the bearing hole 2a formed in the bottom surface 13a of the housing body 2 and the discharge port 19 are communicated with each other by a lateral groove 33 of a bearing oil supply groove also formed in the bottom surface 13a.

  In such a variable displacement oil pump, when the vane 6 receives the discharge pressure from the discharge port 19, as shown in FIG. 11, the vane 6 approaches the center (center line) O of the bearing hole 2a. It falls down. And the corner | angular part 6a of the inner side edge part of the vane 6 may enter into the horizontal groove 33 of a bearing oil supply groove | channel, and may interfere with the edge part 33a of the side surface of the horizontal groove 33. FIG. As a result, there is a problem that the friction increases and the pump efficiency of the variable displacement oil pump decreases.

  FIG. 12 is a cross-sectional view of the housing body 2 and the like showing the oil introduction groove 2f and the periphery thereof in the first embodiment.

  In the variable displacement oil pump 1 of the first embodiment, the oil introduction groove 2f extends from the discharge port 19 toward the center O, but does not extend to the first bearing hole 2a. That is, the bottom surface 13a remains between the terminal end 29 of the oil introduction groove 2f and the first bearing hole 2a. And as shown in FIG. 12, the corner | angular part 6a of the inner side edge part of the vane 6 contacts and is supported by the bottom face 13a.

  Therefore, even when the vane 6 receives the discharge pressure from the discharge port 19, the corner 6a of the inner end of the vane 6 is supported by the bottom surface 13a, so that the vane 6 approaches the center O of the first bearing hole 2a. In this way, the oil does not fall into the oil introduction groove 2f and interference between the corner 6a of the vane 6 and the edge of the oil introduction groove 2f is suppressed. Therefore, friction does not increase, and a decrease in pump efficiency of the variable displacement oil pump 1 is suppressed.

  In the variable displacement oil pump of the prior art, as shown in FIG. 11, when the vane 6 is tilted in the direction approaching the center O of the bearing hole 2a, the corner 6a at the inner end of the vane 6 There is a possibility that the diagonal corners may interfere with a cover member (not shown). As a result, there is a problem that the friction increases and the pump efficiency of the variable displacement oil pump decreases.

  However, in the first embodiment, as shown in FIG. 12, the corner 6a of the vane 6 is supported by the bottom surface 13a, so that the vane 6 falls in the direction approaching the center O of the first bearing hole 2a. Since it is suppressed, interference with the corner | angular part which is opposite to the corner | angular part 6a of the vane 6 and the cover member which is not illustrated is suppressed. Therefore, friction does not increase and the pump efficiency of the variable displacement oil pump 1 is improved.

  Further, in the first embodiment, the housing body 2 having the pump housing chamber 13 and having the first bearing hole 2a in which the drive shaft 4 is supported, and the pump housing chamber 13 are housed. A cam ring 7 that can be decentered with respect to the center, a rotor 5 that is rotationally driven by a drive shaft 4, and a plurality of slits 5 a that are open, and a plurality of slits 5 a that can be received respectively. A plurality of vanes 6 that can protrude and retract in the radial direction, a cover member 3 that is fixed to the housing body 2 and has a second bearing hole 3a that supports the drive shaft 4, and a side surface of the rotor 5 that is centered on the drive shaft 4. A circular recess 23 formed as a ring member 9, a ring member 9 that is accommodated in the circular recess 23, contacts the inner end of the vane 6, and projects a part of the vane 6 from the outer peripheral surface of the rotor 5; At least The suction port 18 that introduces fluid from the outside, the discharge port 19 that discharges the introduced fluid to the outside, the start end 28 opens to the discharge port 19, and the end 29 passes through the circular recess 23. In the variable displacement oil pump 1 having an oil introduction groove 2f extending to a corresponding position between the inner end and the inner end, the oil flows through the oil introduction groove 2f and the circular recess 23 to allow the oil to flow through the first bearing hole 2a and the second bearing hole 2a. It is introduced into the bearing hole 3a.

  Therefore, interference between the vane 6 and the oil introduction groove 2f can be suppressed, and the pump efficiency of the variable displacement oil pump 1 can be improved.

  Further, the depth D of the circular recess 23 is formed larger than the thickness Tr of the ring member 9.

  Accordingly, the oil easily flows from the discharge port 19 to the inner peripheral side of the ring member 9 through the oil introduction groove 2f and the axial gap 34, so that the oil can be easily supplied to the drive shaft 4.

  The diameter of the ring member 9 is smaller than the diameter of the circular recess 23.

  Accordingly, a radial gap 32 is formed between the outer peripheral surface of the ring member 9 and the inner peripheral surface of the peripheral wall 23b of the circular recess 23, whereby the inner end of the vane 6 when viewed in the radial direction is circular. Since it always projects radially inward from the inner peripheral surface of the peripheral wall 23b of the recess 23, the vane 6 can easily follow.

  Furthermore, the ring member 9 is provided with a groove 9b that communicates in the radial direction on its side surface.

  Accordingly, the oil easily flows into the inner peripheral side of the ring member 9 through the groove 9b, so that the oil can be easily supplied to the drive shaft 4.

  Further, the start end 28 of the oil introduction groove 2 f is formed at the end portion 19 b of the discharge port 19.

  As a result, the proportion of the vane 6 accommodated in the slit 5 a of the rotor 5 is increased at the end portion 19 b, and the vane 6 slightly protruding from the outer peripheral surface of the rotor 5 comes into contact with the inner peripheral surface of the cam ring 7. ing. Accordingly, the vane 6 is less likely to fall in the direction of approaching the center O of the first bearing hole 2a due to the discharge pressure from the discharge port, and interference between the corner 6a of the vane 6 and the edge of the oil introduction groove 2f. Is suppressed.

  Further, the end 29 of the oil introduction groove 2f is formed on the upstream side of the rotation of the vane 6 from the start end 28 of the oil introduction groove 2f.

  Accordingly, the oil introduction groove 2f and the vane 6 form an acute angle θ as shown in FIG. As a result, the vane 6 as a whole is prevented from overlapping the oil introduction groove 2f along the radial direction at the terminal end portion 19b of the discharge port 19, and the passing vane 6 falls down with respect to the center O of the first bearing hole 2a. There is no risk of falling into the oil introduction groove 2f. Accordingly, interference between the vane 6 and the oil introduction groove 2f is avoided, and a decrease in pump efficiency of the variable displacement oil pump 1 is suppressed.

  The first bearing hole 2a and the second bearing hole 3a are formed with oil retaining grooves 2e and 3c communicating with the circular recess 23.

  Accordingly, the oil flows into the oil holding grooves 2e and 3c through the circular recesses 23. Thereby, oil is hold | maintained in the oil holding grooves 2e and 3c, and the lubrication of the drive shaft 4 improves.

  Further, the oil introduction groove 2 f extends linearly from the discharge port 19.

  Thereby, in the terminal end portion 19b of the discharge port 19, the overlapping portion along the radial direction between the passing vane 6 and the oil introduction groove 2f is reduced, and the vane 6 falls down with respect to the center O of the first bearing hole 2a. It is difficult to fall into the oil introduction groove 2f. Accordingly, a decrease in pump efficiency of the variable displacement oil pump 1 is suppressed.

  In the first embodiment, the example in which the discharge port 19 and the oil introduction groove 2f are formed in the housing body 2 is disclosed. However, the discharge port 19 and the oil introduction groove 2f may be formed in the cover member 3. good. In this case, since the discharge port 19 and the oil introduction groove 2f may be formed in the plate-like cover member 3 having a simple shape, the workability is improved as compared with the case where these are formed in the housing body 2.

Further, the discharge port 19 and the oil introduction groove 2 f may be formed in both the housing body 2 and the cover member 3. Thereby, it is possible to efficiently lubricate the oil from both the housing main body 2 side and the cover member 3 side to the first and second bearing holes 2a and 3a.
[Second Embodiment]
FIG. 13 shows a front view of the housing body 2 having the oil introduction groove 2g of the second embodiment.

  As shown in FIG. 13, the oil introduction groove 2 g extends in a curved shape from the rear end side of the discharge port 19 in the rotor rotation direction. The oil introduction groove 2g extends in a curved line so as not to completely overlap the vane 6 along the radial direction when the vane 6 passes through the oil introduction groove 2g. In this embodiment, the oil introduction groove 2g extends from the terminal end portion 19b of the discharge port 19 so as to curve in the counterclockwise direction of FIG. The oil introduction groove 2g may extend from the terminal end portion 19b of the discharge port 19 so as to curve in the clockwise direction in FIG.

  FIG. 14 is an assembly diagram of the variable displacement oil pump 1 of the second embodiment with the cover member 3 removed.

As shown by a broken line in FIG. 14, the oil introduction groove 2 g is provided on the rear end side in the rotor rotation direction of the discharge port 19 where the proportion of the vane 6 accommodated in the slit 5 a of the rotor 5 increases. The oil introduction groove 2g extends in a curved line from the rear end side in the rotor rotation direction of the discharge port 19 to a position in a region A between the inner peripheral surface of the peripheral wall 23b of the circular recess 23 and the outer peripheral surface of the ring member 9. Yes. That is, the start end 30 of the oil introduction groove 2g is located at the end portion 19b (see FIG. 13) of the discharge port 19, and the end 31 of the oil introduction groove 2g is on the downstream side of the rotation of the vane 6 from the start end 30. , And extends to a position in the region A between the inner end surface of the base end portion of the vane 6 and the inner peripheral surface of the peripheral wall 23 b of the circular recess 23.
[Effect of the second embodiment]
In addition to the operational effects of the first embodiment, the second embodiment has the following operational effects.

  In the second embodiment, the oil introduction groove 2g extends in a curved shape from the discharge port 19, so that the portion where the passing vane 6 and the oil introduction groove 2g overlap in the radial direction is reduced, and the vane 6 One bearing hole 2a is inclined with respect to the center O and is difficult to fall into the oil introduction groove 2g. Accordingly, a decrease in pump efficiency of the variable displacement oil pump 1 is suppressed.

  As the variable displacement oil pump based on the embodiment described above, for example, the following modes can be considered.

  In one aspect, the variable displacement oil pump has a pump housing chamber, a housing body formed with a first bearing hole in which the drive shaft is supported, and the pump housing chamber. A cam ring that can be decentered with respect to the center, a rotor that is rotationally driven by the drive shaft, and a plurality of slits that are open, and a plurality of slits that can be accommodated in the plurality of slits. A plurality of vanes that can be projected and retracted, a cover member that is fixed to the housing body and has a second bearing hole that supports the drive shaft, and a circular recess that is formed on the side surface of the rotor around the drive shaft A ring member that is accommodated in the circular recess, contacts the inner end of the vane and projects a part of the vane from the outer peripheral surface of the rotor, and the housing body or the cover. A suction port that introduces fluid from the outside, a discharge port that discharges the introduced fluid to the outside, and an inner end of the vane that opens to the discharge port and that passes through the circular recess. And an oil introduction groove extending to a corresponding position. Oil is introduced into the first bearing hole and the second bearing hole through the oil introduction groove and the circular recess.

  In a preferred aspect of the variable displacement oil pump, the depth of the circular recess is formed larger than the thickness of the ring member.

  In another preferred embodiment, in any of the embodiments of the variable displacement oil pump, the diameter of the ring member is smaller than the diameter of the circular recess.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the ring member includes a groove communicating with a radial direction on a side surface thereof.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the start end of the oil introduction groove is formed at the end portion of the discharge port.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the end of the oil introduction groove is formed on the upstream side of the rotation of the vane from the start end of the oil introduction groove.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the oil introduction groove extends in a curved shape from the discharge port.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the first bearing hole and the second bearing hole are formed with an oil retaining groove communicating with the circular recess.

  In still another preferred aspect, in any of the variable displacement oil pump aspects, the oil introduction groove extends linearly from the discharge port.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the discharge port is formed in the housing body and the cover member, and an oil introduction groove is formed from each discharge port. .

DESCRIPTION OF SYMBOLS 1 ... Variable displacement type oil pump, 2 ... Housing main body, 2e ... Oil holding groove, 2f ... Oil introduction groove, 2g ... Oil introduction groove, 3 ... Cover member, 3c ..Oil retaining groove, 4 ... drive shaft, 5 ... rotor, 6 ... vane, 7 ... cam ring, 8 ... coil spring, 9 ... ring member, 9b ... groove DESCRIPTION OF SYMBOLS 10 ... 1st sealing means, 11 ... 2nd sealing means, 13 ... Pump accommodation chamber, 2a ... 1st bearing hole, 3a ... 2nd bearing hole, 5a ... Slit , 18 ... suction port, 19 ... discharge port, 19b ... end portion, 23 ... circular recess, 23a ... bottom wall, 23b ... peripheral wall, 28 ... start end, 29 ... Termination, 30 ... Start, 31 ... Termination, 33 ... Diameter clearance, 34 ... Axial clearance

Claims (11)

A housing body having a pump housing chamber and having a first bearing hole in which the drive shaft is supported;
A cam ring housed in the pump housing chamber and eccentric with respect to the center of the drive shaft;
A rotor that is rotationally driven by the drive shaft and has a plurality of slits open;
A plurality of vanes which are respectively provided so as to be accommodated in the plurality of slits, and which can appear and disappear in a radial direction with respect to the drive shaft;
A cover member fixed to the housing body;
A circular recess formed around the drive shaft on the side of the rotor;
A ring member accommodated in the circular recess, contacting the inner end of the vane and causing a part of the vane to protrude from the outer peripheral surface of the rotor;
A suction port that introduces fluid from the outside and a discharge port that discharges the introduced fluid to the outside, formed on at least one of the housing body or the cover member;
An oil introduction groove having a start end opened to the discharge port and an end extending to a corresponding position between the circular recess and the inner end of the passing vane;
A variable displacement oil pump characterized by comprising:   2. The variable displacement oil pump according to claim 1, wherein a depth of the circular recess is formed larger than a thickness of the ring member.   The variable capacity oil pump according to claim 2, wherein the diameter of the ring member is smaller than the diameter of the circular recess.   The variable capacity oil pump according to claim 1, wherein the ring member has a groove communicating with a radial direction on a side surface thereof.   2. The variable displacement oil pump according to claim 1, wherein a start end of the oil introduction groove is formed at a terminal end of the discharge port.   6. The variable displacement oil pump according to claim 5, wherein a terminal end of the oil introduction groove is formed on the upstream side of the rotation of the vane from a start end of the oil introduction groove.   6. The variable displacement oil pump according to claim 5, wherein the oil introduction groove extends in a curved shape from the discharge port.   2. The variable displacement oil pump according to claim 1, wherein the first bearing hole is formed with an oil retaining groove communicating with the circular recess.   The variable capacity oil pump according to claim 6, wherein the oil introduction groove extends linearly from the discharge port.   The variable displacement oil pump according to claim 1, wherein the discharge port is formed in the housing body and the cover member, and an oil introduction groove is formed from each discharge port.   The variable capacity oil pump according to claim 1, wherein the cover member is formed with a second bearing hole for supporting the drive shaft.

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