JP2017066949A - Variable displacement vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable displacement vane pump capable of inhibiting deformation of a pump housing and so forth caused by the internal pressure of a pump chamber.SOLUTION: A variable displacement vane pump comprises: a pump housing 1 having a pump element housing part 1a; a rotor 12 rotatably provided in the pump element housing part; plural vanes 13 provided on the outer peripheral part of the rotor in a freely projecting and retracting manner; and a cam ring 4 which is provided in the pump element housing part so as to be eccentrically movable and partitions plural pump chambers 14 together with the rotor and vanes. In the variable displacement vane pump, a planar cam ring support surface 36 for abutting and supporting the cam ring is formed at a part of the inner peripheral surface of the pump housing on a first discharge port 17 side, and a planar cam ring side abutting surface 37 is formed at a part of the outer peripheral surface of the cam ring, which is opposite to the cam ring support surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable displacement vane pump used, for example, as a drive source for a continuously variable transmission or a power steering device of an automobile.

  As this type of conventional variable displacement vane pump, one described in Patent Document 1 below is known.

  This variable displacement vane pump is provided with a pump housing having a pump element accommodating portion therein, a drive shaft inserted in the pump element accommodating portion, and provided in the pump element accommodating portion, and is rotationally driven by the drive shaft. A rotor, a plurality of vanes provided in the outer periphery of the rotor, and a plurality of vanes provided on the outer peripheral side of the vanes so as to be able to swing eccentrically, and a plurality of pump chambers are formed on the inner peripheral side together with the rotor and the vanes. And a control valve used for eccentric control of the cam ring.

  Each of the pump chambers sucks the working oil based on the negative pressure generated in the suction region where the volume increases with the rotation of the rotor, and then sucks the sucked working oil with the rotation of the rotor. In the discharge region where the volume decreases, the discharge is made to the outside of the pump based on the positive pressure generated inside. In addition, each pump chamber is set so that the amount of hydraulic fluid discharged (discharge amount) increases as the amount of eccentricity of the cam ring with respect to the rotor (hereinafter simply referred to as “eccentric amount”) increases. Yes.

  The cam ring is a pivot pin inserted between an arc concave pivot groove formed on the outer peripheral portion on the discharge region side and an arc concave support groove formed on the inner peripheral portion on the discharge region side of the pump housing. It swings around the fulcrum.

JP 2012-87777 A

  By the way, in the conventional variable displacement vane pump, as described above, a positive pressure is generated in the pump chamber located in the discharge region. This positive pressure is simultaneously applied to the cam ring by the pivot pin. This will cause a pressing force in the direction.

  For this reason, when the conventional variable displacement vane pump is applied to, for example, a large vehicle that requires high-pressure and large-capacity hydraulic fluid, when the internal pressure of the pump chamber located in the discharge region becomes high, the pivot There is a possibility that stress concentration occurs in the pivot groove and the support groove that are in contact with the pin with a narrow contact area, and the pump housing and the cam ring are partially deformed.

  The present invention has been devised in view of such technical problems, and provides a variable displacement vane pump capable of suppressing deformation of a pump housing and the like due to an internal pressure of a pump chamber.

  In particular, the present invention provides a pump housing having a pump element accommodating portion therein, a drive shaft inserted into the pump element accommodating portion and pivotally supported by the pump housing, and provided in the pump element accommodating portion. A rotor that is driven to rotate by a shaft and has a plurality of slots in the circumferential direction, a plurality of vanes provided in the slots so as to be movable in and out, and movably provided in the pump element housing portion. An annular cam ring that forms a plurality of pump chambers together with the rotor and the vanes, and a suction port that is formed in the pump housing and opens to a suction region in which the volumes of the plurality of pump chambers increase as the rotor rotates. A discharge formed in the pump housing and opened to a discharge region in which the volumes of the plurality of pump chambers decrease as the rotor rotates. And is provided on the inner peripheral surface of the pump housing on the discharge port side, supports the cam ring by contacting the outer peripheral surface of the cam ring, and has a planar shape so that the moving direction of the cam ring is substantially linear. A cam ring support surface formed on the cam ring, a cam ring side contact surface provided on an outer peripheral portion of the cam ring facing the cam ring support surface and formed in a flat shape so as to contact the cam ring support surface, and the pump element The first fluid pressure chamber and the volume provided on the side where the volume is reduced when the cam ring moves to the side where the eccentric amount of the cam ring increases and is separated from each other between the accommodating portion and the radial direction of the cam ring. A second fluid pressure chamber provided on the increasing side, and a biasing member provided in the second fluid pressure chamber for biasing the cam ring toward the first fluid pressure chamber. A control valve for controlling the pressure of both the first fluid pressure chamber and the second fluid pressure chamber, or for controlling the pressure of either the first fluid pressure chamber or the second fluid pressure chamber; It is characterized by having.

  ADVANTAGE OF THE INVENTION According to this invention, deformation | transformation of a pump housing etc. resulting from the internal pressure of a pump chamber can be suppressed.

It is a cross-sectional view of the variable displacement vane pump according to the first embodiment of the present invention. It is the sectional view on the AA line of FIG. It is operation | movement explanatory drawing at the time of engine low rotation of the variable displacement vane pump. It is operation | movement explanatory drawing at the time of engine high rotation of the variable displacement vane pump. It is a cross-sectional view of the variable displacement vane pump according to the second embodiment. It is a cross-sectional view of the variable displacement vane pump according to the third embodiment.

Hereinafter, each embodiment of the variable displacement vane pump according to the present invention will be described in detail with reference to the drawings.
[First Embodiment]
As shown in FIGS. 1 and 2, a variable displacement vane pump according to the present embodiment (hereinafter simply referred to as “pump”) includes a pump housing 1 having a pump element accommodating portion 1a therein, and the pump element accommodating portion. A drive shaft 2 inserted and disposed in 1a; a pump element 3 provided in the pump element housing 1a so as to be integrally rotatable with the drive shaft 2 and performing a suction and discharge operation (pump operation) of hydraulic oil; The pump element 3 is provided on the outer peripheral side of the pump shaft 3 so as to be able to move eccentrically with respect to the axis of the drive shaft 2. It is mainly composed of an annular cam ring 4 that varies the discharge amount and discharge pressure, and a control valve 5 that is used to control the eccentric amount of the cam ring 4.

  As shown in FIGS. 1 to 3, the pump housing 1 includes a housing main body 6 formed in a bottomed cylindrical shape, a housing cover 7 that closes an opening of the housing main body 6, and an inner portion of the housing main body 6. A disk-shaped pressure plate 8 disposed at the bottom, and an annular adapter ring 9 fitted and fixed to the inner peripheral surface of the housing body 6 are provided.

  The housing body 6 and the housing cover 7 are fastened together by bolts 10 being inserted and screwed into a plurality of bolt insertion holes 6a, 7a formed on the outer periphery. The housing body 6 and the housing cover 7 are formed with bearing holes 6b and 7b penetrating at substantially the center position in the axial direction, and both end portions of the drive shaft 2 can be freely rotated by the bearing holes 6b and 7b. It comes to support.

  The adapter ring 9 is sandwiched and fixed by the housing cover 7 and the pressure plate 8, and a cylindrical pin hole 9a is formed in a thick portion between the inner peripheral surface and the outer peripheral surface. The pin hole 9 a is inserted with a rotation restricting pin 11 that positions the adapter ring 9 in the circumferential direction with respect to the housing body 6 and restricts the rotation of the adapter ring 9.

  The drive shaft 2 is rotated in the counterclockwise direction (arrow direction) in FIG. 1 by a driving force transmitted from an unillustrated engine via a gear or the like.

  As shown in FIGS. 1 to 3, the pump element 3 includes a rotor 12 having a plurality of slots 12a radially formed at substantially equal intervals in the circumferential direction of the outer peripheral portion, and the slots 12a appear and disappear. And a plurality of rectangular plate-like vanes 13 provided freely.

  The rotor 12 is splined to the outer periphery of the drive shaft 2 so as to be integrally rotatable. The rotor 12 has a back pressure chamber 12b having a substantially circular cross section into which discharge pressure is introduced at the inner base end of each slot 12a. First and second back pressure ports to be described later when the pump is in operation. The vanes 13 are pushed out in the direction of the inner peripheral surface (the advance direction) of the cam ring 4 based on the discharge pressure introduced into the back pressure chambers 12b via 31a and 31b and the centrifugal force accompanying the rotation of the chambers 31a and 31b. It has become. A plurality of pump chambers 14 are defined between the housing cover 7 and the pressure plate 8 by the outer peripheral surface of the rotor 12, the inner peripheral surface of the cam ring 4 and a pair of adjacent vanes 13 and 13. Yes.

  Each of the pump chambers 14 is formed so that the internal volume thereof increases and decreases with the rotation of the rotor 12, and a negative pressure is generated inside the pump element housing portion 1a in the suction region, which is a region where the volume gradually increases. On the other hand, a positive pressure is generated inside the discharge region, which is a region where the volume gradually decreases. Each pump chamber 14 is configured such that the amount of change in volume accompanying the rotation of the rotor 12 increases as the amount of eccentricity of the cam ring 4 increases.

  Further, the pressure plate 8 constituting the pump chamber 14 has an end surface 8a on the rotor 12 side and an inner end surface 7c of the housing cover 7 and a first suction port 15 having a substantially circular arc shape opening to the suction region, and The second suction port 16 and the substantially arc-concave first discharge port 17 and the second discharge port 18 that open to the discharge region are notched so as to substantially face each other across the drive shaft 2.

  The first suction port 15 includes a suction hole 19 formed in the pressure plate 8, a first suction pressure chamber 20 formed in the inner bottom surface of the housing body 6, and the first suction pressure chamber 20. An oil pan 23 (see FIG. 3) is provided through a first suction passage comprising a communication passage 21 extending in the outer diameter direction of the housing body 6 and a suction port 22 formed in the outer surface of the housing body 6. It is connected to the. On the other hand, the second suction port 16 also has a second suction pressure chamber 24 formed in the inner surface of the housing cover 7, a communication passage 25 that connects the second suction pressure chamber 24 and the suction port 22, and a suction port. Similarly, it is connected to the oil pan 23 through a second suction passage composed of the port 22.

  The first discharge port 17 is connected to the upstream end of the discharge passage 28 via a discharge hole 26 formed in the pressure plate 8 and a discharge pressure chamber 27 formed in the inner bottom surface of the housing body 6. Has been. The discharge passage 28 has a metering orifice 29 that is a passage restricting portion in the middle of the flow passage, and a downstream end thereof is connected to a continuously variable transmission, a power steering device, and the like that are not shown.

  With this configuration, each pump chamber 14 includes the first and second suction passages for the hydraulic oil stored in the oil pan 23 based on the negative pressure generated in the suction region, as shown in FIG. The suctioned hydraulic oil is sucked in through the suction passage 30 and then the sucked hydraulic oil is supplied to the continuously variable transmission or the power through the discharge hole 26, the discharge pressure chamber 27 and the discharge passage 28 based on the positive pressure generated in the discharge region. Discharge (supply) to a steering device or the like.

  Further, as shown in FIGS. 1 to 3, first and second back pressures formed on the end surface 8 a on the rotor 12 side of the pressure plate 8 and the inner end surface 7 c of the housing cover 7 are formed in a substantially annular shape. Ports 31a and 31b are arranged so as to face the respective back pressure chambers 12b. These back pressure ports 31a and 31b communicate with the discharge pressure chamber 27 through an oil passage (not shown), and the discharge pressure is always supplied from the discharge pressure chamber 27.

  The cam ring 4 is integrally formed of a ferrous metal sintered material. Further, in a portion of the inner peripheral surface of the cam ring 4 that is located in a region that does not belong to either the suction region or the discharge region (hereinafter referred to as “vane confinement region X”), the vane is closed. The vane pop-out amount W of the vane 13 located in the intrusion region X from the outer peripheral surface of the rotor 12 is formed to have a constant pressure cam profile (contour shape) that hardly varies with the rotation of the rotor 12.

  The cam ring 4 moves eccentrically based on the hydraulic pressure supplied between its outer peripheral surface and the inner peripheral surface of the adapter ring 9.

  More specifically, as shown in FIGS. 1 and 3, the cam ring 4 is guided between the cam ring 4 and the adapter ring 9 so that the eccentric movement of the cam ring 4 is substantially linear. And a seal mechanism 33 disposed on the substantially opposite side of the drive mechanism 2 with respect to the slide mechanism 32.

  And between the radial direction of the cam ring 4 and the adapter ring 9 sandwiching the slide mechanism 32 and the seal mechanism 33, a first fluid pressure chamber 34 whose volume decreases when the cam ring 4 moves eccentrically, The cam ring 4 is separated from the second fluid pressure chamber 35 whose volume increases when the cam ring 4 moves eccentrically, and hydraulic pressure is supplied to the first and second fluid pressure chambers 34, 35, thereby the cam ring 4. Is designed to move eccentrically.

  The slide mechanism 32 includes a flat cam ring support surface 36 provided at a predetermined portion on the first discharge port 17 side of the inner peripheral surface of the adapter ring 9 and a cam ring support surface 36 on the outer peripheral surface of the cam ring 4. And a flat cam ring side contact surface 37 provided so as to be substantially parallel to the cam ring support surface 36.

  The cam ring support surface 36 supports the cam ring 4 that is pressed in the direction of the cam ring support surface 36 by the internal pressure of the pump chamber 14 located in the discharge region by contacting the cam ring side contact surface 37, as shown in FIG. It is guided to move in the eccentric direction P shown.

  The cam ring side contact surface 37 is formed such that the length in the direction along the eccentric direction P is shorter than the length in the direction along the eccentric direction P of the cam ring support surface 36, and the cam ring side contact surface 37 is related to the eccentric position of the cam ring 4. The cam ring support surface 36 is always in sliding contact.

  The cam ring-side contact surface 37 is provided with a collecting groove 38 that is an oil groove for collecting hydraulic oil. A plurality of the collecting grooves 38 are juxtaposed along the axial direction of the drive shaft 2 of the cam ring side contact surface 37, and each of the collecting grooves 38 is formed in a long groove shape along the eccentric direction P. The hydraulic oil adhering to the cam ring support surface 36 and the cam ring side contact surface 37 is collected and held.

  The cam ring 4 is restricted from rotating in the adapter ring 9 by the cam ring side contact surface 37 contacting the cam ring support surface 36.

  The seal mechanism 33 includes a flat portion 39 provided at a predetermined portion on the first suction port 15 side of the inner peripheral surface of the adapter ring 9 and a pair of first and second provided on the flat portion 39. The seal grooves 40a and 40b, the pair of first and second seal members 41a and 41b respectively accommodated in the seal grooves 40a and 40b, and the portions facing the flat portion 39 of the outer peripheral surface of the cam ring 4, A flat seal sliding contact surface 42 provided so as to be substantially parallel to the flat portion 39.

  The flat portion 39 is formed to be substantially parallel to the eccentric direction P of the cam ring 4, that is, to be substantially parallel to the cam ring support surface 36 of the adapter ring 9.

  The seal grooves 40a and 40b are spaced apart from each other along the eccentric direction P of the cam ring 4 (circumferential direction of the drive shaft 2) and open to the seal sliding contact surface 42, respectively. It is formed in a rectangular concave shape and extends along the axial direction of the drive shaft 2.

  Each of the sealing members 41a and 41b is formed to have a substantially rectangular cross section by an elastic material such as a synthetic resin material or a rubber material, and extends along the axial direction of the drive shaft 2. When stored in the seal grooves 40a and 40b, the front end surface on the cam ring 4 side comes into contact with the seal sliding contact surface 42 to exert a sealing function.

  Regardless of the eccentric position of the cam ring 4, the seal sliding contact surface 42 is formed so as to be in constant contact with the seal members 41 a and 41 b, and the first fluid pressure chamber 34 and the second fluid pressure chamber 35 The liquid-tightness between them is ensured.

  Further, an arcuate concave suction pressure introduction groove 43 is provided between the seal grooves 40 a and 40 b of the flat surface portion 39. The suction pressure introduction groove 43 is formed so as to extend along the axial direction of the drive shaft 2, and at least one of the end portions in the axial direction of the suction passage 30 via an oil passage (not shown). Communicating with The suction pressure is constantly introduced into the space defined by the suction pressure introduction groove 43, the first and second seal members 41a and 41b, and the seal sliding contact surface.

  A cam spring 44 as a biasing member is provided between the cam ring 4 and the adapter ring 9 in the radial direction. This cam spring 44 is notched on the spring housing groove 45 formed in the outer peripheral surface of the cam ring 4 on the second fluid pressure chamber 35 side, and on the inner peripheral surface facing the spring housing groove 45 of the adapter ring 9. It is disposed between the spring housing recess 46 and the cam ring 4 so as to apply a spring force (biasing force) in the eccentric direction P to the cam ring 4. Based on this spring force, the cam ring 4 is constantly urged in the direction in which the amount of eccentricity is maximized.

  As shown in FIGS. 1 and 3, the control valve 5 performs eccentric control of the cam ring 4 by adjusting the internal pressure of both the first and second fluid pressure chambers 34, 35. A control valve, which is a control valve housing hole 51 formed in the housing body 6 so as to be orthogonal to the drive shaft 2, and a spool valve body 52 movably provided in the control valve housing hole 51. A solenoid 53 that is provided on one end side in the axial direction of the control valve housing hole 51 and applies a biasing force to the spool valve body 52 toward the other end side in the axial direction; A plug 54 that closes the end opening, and a valve spring 55 that is interposed between the plug 54 and the spool valve body 52 and biases the spool valve body 52 toward one end in the axial direction are provided.

  The spool valve body 52 has a first land portion 52a formed on one end side in the axial direction on the solenoid 53 side and a second land portion 52b formed on the other end portion in the axial direction on the plug 54 side. .

  The first and second land portions 52a and 52b have their outer peripheral surfaces in sliding contact with the inner peripheral surface of the control valve accommodating hole 51 with a minute clearance, and the inner space of the control valve accommodating hole 51 is defined in the first space. -It divides into the 3rd pressure chambers 56-58.

  The first pressure chamber 56 is formed on the solenoid 53 side with respect to the first land portion 52a of the control valve housing hole 51, and more than the metering orifice 29 via the first spool control pressure introduction passage 59. It communicates with the discharge passage 28 on the upstream side, and discharge pressure on the upstream side of the metering orifice 29 is introduced therein. The first spool control pressure introduction passage 59 is provided with a damper orifice 59a that reduces hydraulic oil pulsation and the like by reducing the flow passage area.

  The second pressure chamber 57 is formed closer to the plug 54 than the second land portion 52 b of the control valve housing hole 51, and more than the metering orifice 29 via the second spool control pressure introduction passage 60. It communicates with the discharge passage 28 on the downstream side, and discharge pressure on the downstream side of the metering orifice 29 is introduced therein.

  The third pressure chamber 58 is provided between the first land portion 52a and the second land portion 52b of the control valve housing hole 51 and, as shown in FIG. It communicates with the outside of the pump housing 1 so that atmospheric pressure is introduced into the inside.

  In addition, annular first and second annular grooves 62 and 63 are provided at predetermined portions on the inner peripheral surface of the control valve accommodating hole 51 that overlap the outer peripheral surfaces of the first and second land portions 52a and 52b, respectively. Is notched.

  The first annular groove 62 on the first land portion 52a side communicates with the first pressure chamber 56 or the third pressure chamber 58 as appropriate according to the sliding position of the spool valve body 52 and penetrates through the groove bottom. The first fluid pressure introduction passage 64 is formed, and the first fluid pressure introduction hole 65 formed in the adapter ring 9 so as to communicate with the first fluid pressure introduction passage 64. It is connected to the chamber 34.

  On the other hand, the second annular groove 63 on the second land portion 52b side communicates appropriately with the second pressure chamber 57 or the third pressure chamber 58 according to the sliding position of the spool valve body 52, and the bottom of the groove The second fluid pressure introduction passage 66 formed through the second fluid pressure introduction passage 66 and the second fluid pressure introduction hole 67 formed in the adapter ring 9 so as to communicate with the second fluid pressure introduction passage 66. It is connected to the fluid pressure chamber 35.

  The first fluid pressure introduction hole 65 is disposed at a position where the opening end on the side communicating with the first fluid pressure chamber 34 avoids the cam ring support surface 36 in the inner peripheral surface of the adapter ring 9, The opening end of the second fluid pressure introducing hole 67 on the side communicating with the second fluid pressure chamber 35 is disposed at a position where the cam ring support surface 36 is avoided on the inner peripheral surface of the adapter ring 9.

The solenoid 53 is driven and controlled in accordance with the driving condition of the vehicle, and presses one end surface of the spool valve body 52 via a rod 53a provided in the first pressure chamber 56 so as to be extendable and contractable. The position of the spool valve body 52 is controlled in an auxiliary manner.
[Effects of this embodiment]
First, when the drive shaft 2 rotates with the start of the engine, the rotor 12 rotates with the cam ring 4 being maximally decentered with respect to the rotor 12 by the spring force of the cam spring 44 as shown in FIG. . Then, the pump operation is performed in the cam ring 4 and the hydraulic oil sucked from the first and second suction ports 15 and 16 is pressurized with the volume change in each pump chamber 14, The ink is discharged to the discharge passage 28 through the first discharge port 17 and the like. Most of the hydraulic oil discharged to the discharge passage 28 passes through the metering orifice 29 and is supplied to a continuously variable transmission, a power steering device, etc., not shown.

  At this time, part of the hydraulic oil is introduced into the first pressure chamber 56 from the upstream side of the metering orifice 29 and is introduced into the second pressure chamber 57 from the downstream side of the metering orifice 29. . The control is performed based on a differential pressure between the hydraulic pressure of the hydraulic oil in the first pressure chamber 56 and the hydraulic pressure of the hydraulic oil in the second pressure chamber 57 (hereinafter referred to as “valve differential pressure”). The position control of the valve 5 and the control of the discharge amount associated therewith are performed.

  More specifically, until the in-valve differential pressure reaches a predetermined value, the spool valve body 52 is moved by the spring force of the valve spring 55 as shown in FIG. It is kept pressed to the side.

  Then, since the first fluid pressure chamber 34 is disconnected from the first pressure chamber 56 and communicates with the third pressure chamber 58, atmospheric pressure is introduced therein, while the second fluid The pressure chamber 35 communicates with the second pressure chamber 57 to introduce discharge pressure therein.

  As a result, the cam ring 4 is held at the maximum eccentric position by the discharge pressure acting on the second fluid pressure chamber 35 and the spring force of the cam spring 44, so that the discharge amount of the pump is the rotation of the rotor 12. It increases almost in proportion to the increase in speed.

  Next, when the rotational speed of the drive shaft 2 increases, the differential pressure before and after the metering orifice 29 increases as the discharge pressure increases. As shown in FIG. 4, the spool valve body 52 moves a predetermined amount of stroke toward the plug 54 in accordance with the pressure difference in the valve.

  Then, since the second fluid pressure chamber 35 is disconnected from the second pressure chamber 57 and communicates with the third pressure chamber 58, atmospheric pressure is introduced into the second fluid pressure chamber 35, while the first fluid is introduced into the second fluid pressure chamber 35. A discharge pressure is introduced into the pressure chamber 34 by communicating with the first pressure chamber 56.

  Thus, the cam ring 4 slides toward the second fluid pressure chamber 35 in the direction in which the amount of eccentricity decreases against the spring force of the cam spring 44 by the discharge pressure acting on the first fluid pressure chamber 34. As a result, the discharge amount of the pump is reduced.

  In the present embodiment, the cam ring support surface 36 that supports the cam ring 4 and the cam ring side contact surface 37 that contacts the cam ring support surface 36 are formed in a flat shape, and both the 36 and 37 are formed. They are in contact with each other over a wide area.

  As a result, the pressing force Q based on the internal pressure of the pump chamber 14 located in the discharge region, which acts on the cam ring support surface 36 via the cam ring side contact surface 37, can be applied over a wide area of the cam ring support surface 36. Since it can receive in a distributed manner, the adapter ring 9 can be prevented from being deformed due to stress concentration. Similarly, the cam ring side abutting surface 37 can receive the reaction force of the pressing force Q in a wide area in a distributed manner, so that deformation based on the stress concentration of the cam ring 4 can also be suppressed.

  Therefore, according to the present embodiment, deformation of the cam ring 4 and the adapter ring 9 based on the internal pressure of the pump chamber 14 located in the discharge region can be suppressed, thereby improving the durability of the pump.

  In addition, as the durability is improved, the pump can cope with higher discharge pressure and discharge amount, so that the pump can be easily applied to a large vehicle requiring high-pressure and large-flow hydraulic fluid. It can be carried out.

  Further, in the present embodiment, the first seal member 41a and the second seal member 41b are provided between the first fluid pressure chamber 34 and the second fluid pressure chamber 35 between the cam ring 4 and the adapter ring 9 in the radial direction. Thus, the sealing function can be sufficiently exerted between the fluid pressure chambers 34 and 35.

  In the present embodiment, since the control system of the cam ring 4 is a full pressure system, a high urging force is applied to the cam ring 4 during the eccentric control of the cam ring 4. Thereby, even when the cam ring 4 is fixed to the adapter ring 9 or the pressure plate 8 or the like, the cam ring 4 can be moved along the eccentric direction P based on a high biasing force. Become.

  In this configuration, when the present invention is applied to a pump for CVT in which contamination is likely to occur in the hydraulic oil and the cam ring 4 and the pressure plate 8 are liable to be stuck due to the contamination. Especially useful.

  Furthermore, in the present embodiment, in the total pressure pump, a suction pressure introduction groove for introducing suction pressure between the first and second seal members 41a and 41b that separate the fluid pressure chambers 34 and 35. 43 was provided.

  Thereby, even if discharge pressure is introduced into any of the first and second fluid pressure chambers 34 and 35, the seal members 41a and 41b accommodated in the seal grooves 40a and 40b Since the suction pressure introduction groove 43 maintains the state of being drawn toward the suction pressure introduction groove 43 based on the suction pressure, each of the first and second fluid pressure chambers 34 and 35 has a variation in the internal pressure. The rampage of the seal members 41a and 41b can be suppressed. As a result, the sealing performance between the first and second fluid pressure chambers 34 and 35 by the sealing members 41a and 41b and the durability of the sealing members 41a and 41b can be improved.

  Further, in the present embodiment, since the seal sliding contact surface 42 is formed in a flat shape, the contact property between the seal sliding contact surface 42 and the front end surfaces of the seal members 41a and 41b is improved. The liquid tightness between the first and second fluid pressure chambers 34 and 35 is further improved.

  In particular, in this embodiment, the seal sliding contact surface 42 is always in contact with the seal members 41a and 41b regardless of the sliding position of the cam ring 4, so that the first and second fluid pressures can be obtained. The liquid tightness between the chambers 34 and 35 can be further improved.

  Further, in this embodiment, the cam ring support surface 36 and the seal sliding contact surface 42 are formed so as to be parallel to each other, so that the seal sliding contact surface 42 is moved to the respective seals as the cam ring 4 moves eccentrically. There is no approach to or separation from the members 41a and 41b. Thereby, since the movement to the radial direction of the cam ring 4 of each said seal member 41a, 41b is suppressed, durability of each said seal member 41a, 41b can be improved.

  Further, since the seal members 41a and 41b do not need to be formed in the radial direction of the cam ring 4 in consideration of the movement of the cam ring 4 in the radial direction, the seal members 41a, 41b, Similarly, it is not necessary to form deeper groove depths for the seal grooves 40a and 40b for accommodating 41b. Thereby, since the thickness of the location which comprises the seal mechanism 33 of the said adapter ring 9 is securable, durability of this adapter ring 9 can be improved further.

  Further, in the present embodiment, the open end of the fluid pressure introducing holes 65 and 67 on the side communicating with the corresponding fluid pressure chambers 34 and 35 is avoided from the cam ring support surface 36 on the inner peripheral surface of the adapter ring 9. Since the cam ring support surface 36 is eccentrically moved, the cam ring support surface 36 does not cause a problem that the fluid pressure introducing holes 65 and 67 are blocked. Thereby, since the hydraulic pressure is appropriately introduced into the first and second fluid pressure chambers 34 and 35, the accuracy of the eccentric control of the cam ring 4 can be improved.

  Furthermore, in this embodiment, since the cam ring side contact surface 37 is provided with a collecting groove 38 for collecting hydraulic oil, the cam ring side contact surface 37 is in contact with the cam ring support surface 36. The hydraulic oil is supplied between the both 36 and 37. Thereby, the smooth slidability between the cam ring support surface 36 and the cam ring side contact surface 37 is ensured, and the occurrence of seizure between the both 36 and 37 can be suppressed.

  Further, in the present embodiment, the collection groove 38 is provided so as not to communicate with the first and second fluid pressure chambers 34 and 35, so that each fluid pressure chamber 34 through the collection groove 38 is provided. , 35 is suppressed from leaking, the accuracy of the eccentric control of the cam ring 4 is further improved.

By the way, in the vane type variable displacement pump, the cam profile in the vane confinement region on the inner peripheral surface of the cam ring is curved with a predetermined gradient so that the internal pressure of the pump chamber located in the confinement region is discharged. Generally, a method of adjusting to a desired pressure state in advance before reaching the value is performed.
However, in a variable displacement vane pump of the type in which the cam ring swings around a swing fulcrum pin interposed between the pump housing and the cam ring, such as the variable displacement vane pump described in Patent Document 1. Since the gradient of the cam profile fluctuates when swinging, even if a desired cam profile is obtained in a specific eccentric state, the desired cam profile cannot be obtained in other eccentric states.

  On the other hand, in the pump of this embodiment, the eccentric movement of the cam ring 4 is made substantially linear. Therefore, even if the inner peripheral surface of the cam ring 4 is separated or approaches in accordance with the movement, the cam The slope of the profile does not change. For this reason, according to this embodiment, it is possible to obtain a consistent cam profile regardless of the eccentric state of the cam ring 4.

  As described above, the pump of this embodiment is set to a cam profile in which the vane pop-out amount W is constant. As a result, the internal pressure of the pump chamber 14 located in the vane confinement region X is always kept constant until reaching the discharge region as the drive shaft 2 rotates.

Further, in the present embodiment, the pin hole 9a is provided in a thick portion between the inner peripheral surface and the outer peripheral surface of the adapter ring 9, and the rotation restricting pin 11 is inserted into the pin hole 9a so that the housing main body is inserted. Since the adapter ring 9 is positioned in the circumferential direction with respect to 6, the rotation restricting pin 11 does not prevent the cam ring 4 from sliding.
[Second Embodiment]
FIG. 5 shows a second embodiment of the present invention, and the basic configuration is the same as that of the first embodiment, but the eccentric control of the cam ring 4 is changed to hydraulic control of both the first and second fluid pressure chambers 34 and 35. The total pressure method based on this is changed to a so-called low pressure method which is performed by controlling only the hydraulic pressure of the first fluid pressure chamber 34.

  In other words, the pump according to the present embodiment is modified so that the third pressure chamber 58 is constantly supplied with suction pressure through a communication path (not shown) that communicates with the suction portion. Further, the second annular groove 63 is eliminated, and the second fluid pressure introduction passage 66 is always in communication with the third pressure chamber 58 irrespective of the sliding position of the spool valve body 52. With this configuration, the suction pressure is always introduced into the second fluid pressure chamber 35.

  In the present embodiment, the internal pressure of the first fluid pressure chamber 34 is always higher than the internal pressure of the second fluid pressure chamber 35, and the suction pressure introduction groove 43 that suppresses the ramping of the seal member on the flat portion 39. Therefore, the suction pressure introduction groove 43 is abolished. In addition, the seal between the flat portion 39 and the seal sliding contact surface 42 by the seal mechanism 33 is also based on the first seal member 41a only from the double seal structure by the first and second seal members 41a and 41b. The seal structure is changed, and the second seal groove 40b and the second seal member 41b are abolished from the flat portion 39.

  Therefore, according to this embodiment, the eccentric control of the cam ring 4 is performed based on the relative difference between the hydraulic pressure in the first fluid pressure chamber 34 and the spring force of the cam spring 44. In this case, Also, the same operational effects as those of the first embodiment can be obtained.

Further, in this embodiment, since the suction pressure is always introduced into the second fluid pressure chamber 35 and the discharge pressure does not act, the discharge pressure leaks outside the pump through the second fluid pressure chamber 35. The problem that it does not occur. Thereby, the fall of pump efficiency can be suppressed.
[Third Embodiment]
FIG. 6 shows a third embodiment of the present invention, and the basic configuration is the same as that of the second embodiment.
The cam ring support surface 36 is formed to be inclined with respect to an imaginary line L described later.

  That is, the cam ring support surface 36 of the present embodiment has a first intermediate point M1 as an intermediate point between the terminal end 15e of the first suction port 15 and the start end 17s of the first discharge port 17 in the rotation direction of the rotor 12. When an intermediate point between the terminal end 17e of the discharge port 17 and the starting end 15s of the suction port 15 is a second intermediate point M2, a virtual line L passing through the first intermediate point M1 and the second intermediate point M2 (two in FIG. 6). And the distance D to the second intermediate point M2 side gradually decreases from the first intermediate point M1 side toward the second intermediate point M2 side.

  Along with this, the cam ring side contact surface 37 of the cam ring 4 facing the cam ring support surface 36 is also formed in an inclined shape so as to be substantially parallel to the cam ring support surface 36. The moving direction is regulated to an eccentric direction P2 substantially parallel to the inclination direction of the cam ring support surface 36.

  Further, the flat portion 39 and the seal sliding contact surface 42 constituting the seal mechanism 33 are also formed in an inclined shape so as to be substantially parallel to the cam ring support surface 36, and the cam spring 44 has its spring force. The cam ring support surface 36 is disposed so as to be exhibited along the inclination direction, that is, along the eccentric direction P2 of the cam ring 4.

  The low-pressure pump has an advantage that leakage of hydraulic oil from the second fluid pressure chamber 35 is suppressed by introducing suction pressure into the second fluid pressure chamber 35, but the cam ring 4 Since the force for urging the cam ring 4 toward the first fluid pressure chamber 34 is only the spring force of the cam spring 44, there is a concern that the urging force is insufficient when the cam ring 4 is moved eccentrically.

However, in this embodiment, since the cam ring support surface 36 is provided with the inclination as described above, the component force Q _P2 , which is the component in the eccentric direction P2 of the pressing force Q, is applied to the eccentric direction P2 of the cam ring 4. It can be used as a biasing force. Thereby, even if the control method of the cam ring 4 is a low pressure type, the eccentric control of the cam ring 4 can be performed without any problem.

  In the present embodiment, the cam spring 44 is arranged so that the spring force is exerted along the inclination direction of the cam ring support surface 36, so that no bending load is generated on the cam spring 44. The spring force according to the design value can be applied to the cam ring 4.

  The present invention is not limited to the configuration of each of the embodiments described above, and the configuration can be changed without departing from the spirit of the invention.

  For example, in each of the above embodiments, among the elements constituting the seal mechanism 33, the flat portion 39 and the first and second seal grooves 40a and 40b are provided on the adapter ring 9 side, while the seal sliding contact Although it has been described that the surface 42 is provided on the cam ring 4 side, it is possible to replace the locations of these elements.

  In each of the above embodiments, the collecting groove 38 is described as being provided on the cam ring side contact surface 37. However, the collecting groove 38 may be provided on the cam ring support surface 36. In this case, the collection groove 38 is limited to a range that is always in contact with the cam ring-side contact surface 37, so that the first and second fluid pressure chambers 34, 35 through the collection groove 38 are provided. Unintended flow of hydraulic oil can be suppressed.

  Furthermore, in each said embodiment, although the internal peripheral surface located in the vane confinement area | region X of the said cam ring 4 was demonstrated as what has a constant pressure cam profile, the pump chamber 14 located in this area | region has It is also possible to form a cam profile that is in a slightly compressed (pre-compressed) state in advance, that is, the vane pop-out amount W of the vane 13 gradually decreases as the rotor 12 rotates. In this case, since the pressure difference when each pump chamber 14 moves from the vane confinement region X to the discharge region is reduced, vibration and noise associated with the pulse pressure generated based on the pressure difference are suppressed. be able to.

The technical idea grasped from the embodiment will be described below.
[Claim a]
The variable displacement vane pump according to claim 1,
The variable displacement vane pump, wherein the control valve is configured to control pressures of both the first fluid pressure chamber and the second fluid pressure chamber.
[Claim b]
The variable displacement vane pump according to claim 1,
The cam ring includes a seal sliding contact surface that is in sliding contact with the first seal member and the second seal member on an outer peripheral surface;
The variable displacement vane pump, wherein the seal sliding contact surface is formed in a flat shape.
[Claim c]
The variable displacement vane pump according to claim b,
The variable displacement vane pump, wherein the seal sliding contact surface is always in sliding contact with the first seal member and the second seal member regardless of the eccentric position of the cam ring.
[Claim d]
The variable displacement vane pump according to claim b,
The variable displacement vane pump, wherein the seal sliding contact surface is formed to be parallel to the cam ring support surface.
[Claim e]
The variable displacement vane pump according to claim 1,
The pump housing has a first pressure introduction hole and a second pressure introduction hole for introducing pressure from the control valve to the first fluid pressure chamber and the second fluid pressure chamber,
The variable displacement vane pump, wherein opening ends of the first pressure introduction hole and the second pressure introduction hole facing the pump element housing portion are disposed so as to avoid the cam ring support surface.
[Claim f]
The variable displacement vane pump according to claim 1,
An oil displacement groove is formed in the cam ring support surface or the cam ring side contact surface.
[Claim g]
The variable displacement vane pump according to claim f,
The variable capacity vane pump, wherein the oil groove is provided so as not to communicate between the first fluid pressure chamber and the second fluid pressure chamber.
[Claim h]
The variable displacement vane pump according to claim 2,
The variable displacement vane pump, wherein the urging mechanism is arranged to exert an urging force along an inclination direction of the cam ring support surface.
[Claim i]
The variable displacement vane pump according to claim 2,
The inner peripheral surface of the cam ring in the vane confinement region that does not belong to either the suction region or the discharge region has a constant pressure cam profile in which the amount of protrusion of the vane from the rotor does not vary with the rotation of the rotor. A variable displacement vane pump characterized in that it is formed.
[Claim j]
The variable displacement vane pump according to claim 2,
The inner peripheral surface of the cam ring in the vane confinement region that does not belong to either the suction region or the discharge region has a pre-compression cam profile in which the amount of protrusion of the vane from the rotor gradually decreases as the rotor rotates. This is a variable displacement vane pump.
[Claim k]
The variable displacement vane pump according to claim 2,
The pump housing includes an annular adapter ring that constitutes a peripheral wall of the pump element accommodating portion, and a housing body that accommodates the adapter ring,
The adapter ring is accommodated in a state in which rotation is restricted with respect to the housing body by a rotation restricting pin inserted through a pin hole formed between an outer peripheral surface and an inner peripheral surface of the adapter ring. This is a variable displacement vane pump.

DESCRIPTION OF SYMBOLS 1 ... Pump housing 1a ... Pump element accommodating part 2 ... Drive shaft 4 ... Cam ring 5 ... Control valve 12 ... Rotor 12a ... Slot 13 ... Vane 15 ... 1st inlet (inlet)
16 ... Second suction port (suction port)
17 ... 1st discharge port (discharge port)
18 ... Second discharge port (discharge port)
33 ... Seal mechanism 34 ... First fluid pressure chamber 35 ... Second fluid pressure chamber 36 ... Cam ring support surface 37 ... Cam ring side contact surface 41a ... First seal member 41b ... Second seal member 44 ... Cam spring (biasing member) )

Claims (2)

A pump housing having a pump element housing therein;
A drive shaft that is inserted into the pump element housing and is pivotally supported by the pump housing;
A rotor that is provided in the pump element housing portion, is driven to rotate by the drive shaft, and has a plurality of slots in the circumferential direction;
A plurality of vanes provided in the slot so as to be freely movable, and
An annular cam ring which is movably provided in the pump element accommodating portion and forms a plurality of pump chambers together with the rotor and the vane on the inner peripheral side;
A suction port formed in the pump housing and opening to a suction region in which the volumes of the plurality of pump chambers increase with rotation of the rotor;
A discharge port formed in the pump housing and opening to a discharge region in which the volumes of the plurality of pump chambers decrease as the rotor rotates;
Provided on the inner peripheral surface of the pump housing on the discharge port side, supports the cam ring by contacting the outer peripheral surface of the cam ring, and is formed in a flat shape so that the moving direction of the cam ring is substantially linear. Cam ring support surface,
A cam ring side contact surface provided on an outer peripheral portion of the cam ring facing the cam ring support surface and formed in a flat shape so as to contact the cam ring support surface;
A seal mechanism having a first seal member and a second seal member disposed on the suction port side between the pump housing and the cam ring;
When the cam ring moves to the side where the eccentric amount of the cam ring increases and is separated between the pump element housing portion and the radial direction of the cam ring by the seal mechanism, the first is provided on the side where the volume decreases. A first fluid pressure chamber and a second fluid pressure chamber provided on the side of increasing volume;
A biasing member provided inside the second fluid pressure chamber and biasing the cam ring toward the first fluid pressure chamber;
A control valve for controlling the pressure of both the first fluid pressure chamber and the second fluid pressure chamber, or for controlling the pressure of either the first fluid pressure chamber or the second fluid pressure chamber;
A variable displacement vane pump characterized by comprising: A pump housing having a pump element housing therein;
A drive shaft that is inserted into the pump element housing and is pivotally supported by the pump housing;
A rotor that is provided in the pump element housing portion, is driven to rotate by the drive shaft, and has a plurality of slots in the circumferential direction;
A plurality of vanes provided in the slot so as to be freely movable, and
An annular cam ring which is movably provided in the pump element accommodating portion and forms a plurality of pump chambers together with the rotor and the vane on the inner peripheral side;
A suction port formed in the pump housing and opening to a suction region in which the volumes of the plurality of pump chambers increase with rotation of the rotor;
A discharge port formed in the pump housing and opening to a discharge region in which the volumes of the plurality of pump chambers decrease as the rotor rotates;
Provided on the inner peripheral surface of the pump housing on the discharge port side, supports the cam ring by contacting the outer peripheral surface of the cam ring, and is formed in a flat shape so that the moving direction of the cam ring is substantially linear. Once and
In the case where the intermediate point between the end of the suction port and the start end of the discharge port in the rotation direction of the rotor is a first intermediate point, and the intermediate point between the end of the discharge port and the start end of the suction port is a second intermediate point The cam ring support formed in an inclined shape so that a distance between the first intermediate point and a virtual line passing through the second intermediate point gradually decreases from the first intermediate point side toward the second intermediate point side. Surface,
A cam ring side contact surface provided on an outer peripheral portion of the cam ring facing the cam ring support surface and formed in a flat shape so as to contact the cam ring support surface;
A first fluid pressure chamber formed between the pump element housing portion and the cam ring in the radial direction, provided on the side where the volume decreases when the cam ring moves to the side where the eccentric amount of the cam ring increases; A second fluid pressure chamber provided on the side where the volume increases,
A biasing member provided inside the second fluid pressure chamber and biasing the cam ring toward the first fluid pressure chamber;
A control valve for controlling the pressure of the first fluid pressure chamber;
A variable displacement vane pump characterized by comprising:

Images