JP2012202268A - Vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vane pump in which suction defect of hydraulic fluid is prevented.SOLUTION: A vane pump 100 for supplying hydraulic fluid from a main pump chamber 41 and a sub pump chamber 42 to hydraulic equipment 110, includes: a main suction passage 60 communicating a tank 120 for storing the hydraulic fluid therein with the main pump chamber 41; a main discharge passage 70 communicating the main pump chamber 41 with the hydraulic equipment 110; a sub suction passage 80 branched from a branch portion 61 of the main suction passage 60 and communicating the tank 120 with the sub pump chamber 42; a sub discharge passage 90 communicating the sub pump chamber 42 with the hydraulic equipment 110; and a valve mechanism 200 which switches a flow passage of the hydraulic fluid by disconnecting the main suction passage 60 downstream from the branch portion 61 so as not to communicate the tank 120 with the main pump chamber 41, and by connecting the sub discharge passage 90 to the main suction passage 60 so as to supply the hydraulic fluid discharged from the sub pump chamber 42 to the main pump chamber 41.

Description

  The present invention relates to a vane pump used as a hydraulic pressure supply source that supplies hydraulic oil as a working fluid to hydraulic equipment.

  Patent Document 1 includes a rotor connected to a drive shaft, a plurality of vanes provided so as to be movable in a radial direction with respect to the rotor, a cam ring having an inner peripheral surface on which a tip of the vane can slide, a vane, The main pump chamber and the sub pump chamber defined by the rotor and the cam ring, the suction passage for guiding the hydraulic oil stored in the tank to the main pump chamber and the sub pump chamber, and the hydraulic oil from the main pump chamber and the sub pump chamber to the hydraulic equipment A vane pump comprising a discharge passage for guiding is disclosed.

  In this vane pump, the discharge flow rate of the hydraulic oil to the hydraulic equipment changes according to the rotational speed of the rotor. Therefore, when the rotor is at a high rotational speed, the discharge flow rate of the vane pump is adjusted by returning the hydraulic oil discharged from the sub pump chamber to the suction passage.

JP 2005-299471 A

  In the vane pump as described above, since the hydraulic oil is always supplied to both the main pump chamber and the sub pump chamber via the suction passage, the suction flow rate of the hydraulic oil sucked into the suction passage tends to increase at a high rotational speed of the rotor. Cavitation may occur in the suction passage in the vicinity of the connection position with the tank. As described above, when the suction failure of the hydraulic oil occurs in the vane pump, the hydraulic oil cannot be stably supplied from the vane pump to the hydraulic equipment.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vane pump that can prevent poor working fluid suction.

  The present invention includes a rotor coupled to a drive shaft, a plurality of vanes provided so as to be movable in a radial direction with respect to the rotor, a cam ring having an inner peripheral surface on which a tip of the vane can slide, and the vane A main pump chamber and a sub pump chamber defined by the rotor and the cam ring, and a tank for storing the working fluid in a vane pump that supplies the working fluid to the hydraulic equipment from the main pump chamber and the sub pump chamber A main suction passage communicating the tank and the main pump chamber, a main discharge passage communicating the main pump chamber and the hydraulic device, and a branch from the branch portion of the main suction passage, the tank and the sub pump A sub-suction passage communicating with the chamber, a sub-discharge passage communicating between the sub-pump chamber and the hydraulic device, the tank and the front The sub-discharge passage is configured to block the main suction passage downstream of the branch portion so as not to communicate with the main pump chamber, and to supply the working fluid discharged from the sub-pump chamber to the main pump chamber. And a valve mechanism capable of switching the flow path of the working fluid.

  According to the present invention, at a high rotational speed of the rotor, the vane pump sucks the working fluid in the tank by the sub-pump chamber, guides the sucked working fluid to the main pump chamber, and supplies the working fluid from the main pump chamber to the hydraulic equipment. Can be supplied. Therefore, the suction flow rate of the working fluid in the vane pump is smaller than the suction flow rate of the conventional vane pump that sucks the working fluid by both the main pump chamber and the sub pump chamber. Thereby, it is possible to suppress the occurrence of cavitation in the main suction passage in the vicinity of the connection position with the tank, and it is possible to prevent defective suction of the working fluid in the vane pump.

It is a top view of the vane pump by an embodiment of the present invention, and is a figure showing the state where a pump cover was removed. FIG. 3 is a hydraulic circuit diagram of the vane pump in a full discharge state. It is a hydraulic circuit diagram of the vane pump in a half discharge state. It is a top view of the vane pump by a modification, Comprising: It is a figure which shows the state which removed the pump cover.

  A vane pump 100 according to an embodiment of the present invention will be described with reference to the drawings.

  With reference to FIG.1 and FIG.2, the structure of the vane pump 100 by embodiment of this invention is demonstrated.

  As shown in FIG. 1, the vane pump 100 is a pump used as a hydraulic pressure supply source for a power steering device, a transmission, or the like mounted on a vehicle. The vane pump 100 includes a rotor 10 connected to an end portion of a drive shaft 1, a plurality of vanes 20 provided so as to be capable of reciprocating in the radial direction with respect to the rotor 10, and a cam in which a tip portion of the vane 20 can slide. A cam ring 30 having a surface 31.

  The drive shaft 1 is rotationally driven based on the power of the engine provided in the vehicle. The rotor 10 fixed to the end of the drive shaft 1 rotates with the rotation of the drive shaft 1. In FIG. 1, the rotor 10 rotates clockwise.

  The rotor 10 is provided with a plurality of slits 11 formed so as to open on the outer peripheral surface and both end surfaces. These slits 11 are arranged radially with respect to the rotation center of the rotor 10. A vane 20 is slidably inserted into the slit 11. A back pressure chamber 12 into which a part of the hydraulic oil discharged from the vane pump 100 is guided is formed at the base portion of the slit 11. The vane 20 is pushed outward in the radial direction by the hydraulic oil in the back pressure chamber 12, and the tip of the vane 20 comes into contact with a cam surface 31 as an inner peripheral surface of the cam ring 30. A plurality of pump chambers 40 are defined by the outer peripheral surface of the rotor 10, the cam surface 31 of the cam ring 30, and the adjacent vanes 20.

  The cam ring 30 is an annular member that can accommodate the rotor 10. The inner peripheral surface of the cam ring 30 is configured as a cam surface 31, and the cam surface 31 is formed in a substantially oval shape in plan view. On the cam surface 31 of the cam ring 30, two suction regions 32A and 32B in which the volume of the pump chamber 40 expands and two discharge regions 33A and 33B in which the volume of the pump chamber 40 contracts are formed. Therefore, the pump chamber 40 expands and contracts as the rotor 10 rotates.

  The suction region 32A and the suction region 32B are provided at positions that are substantially symmetric with respect to the axis of the cam ring 30, and the discharge region 33A and the discharge region 33B are also provided at positions that are substantially symmetric with respect to the axis of the cam ring 30. It is done.

  The drive shaft 1 is rotatably supported with respect to the pump body 2 by a bearing (not shown). The pump body 2 includes an accommodation recess 2 </ b> A that can accommodate the rotor 10, the cam ring 30, and the side plate 3.

  The side plate 3 and the cam ring 30 are disposed in a stacked state in the housing recess 2A. A pump cover (not shown) is fastened to the end 2B on the opening side of the pump body 2, and the housing recess 2A is sealed by the pump cover.

  As shown in FIG. 2, an arc-shaped suction port that opens to the end surface of the pump cover facing the side plate 3 corresponding to the suction region 32A and supplies hydraulic oil to the pump chamber 40 located in the suction region 32A. 51A and an arcuate suction port 51B that opens corresponding to the suction region 32B and supplies hydraulic oil to the pump chamber 40 located in the suction region 32B are formed.

  In addition, an arc-shaped discharge port 52A that opens to correspond to the discharge region 33A and discharges the hydraulic oil of the pump chamber 40 located in the discharge region 33A on the end surface of the side plate 3 that faces the pump cover, and a discharge region An arcuate discharge port 52B that opens corresponding to 33B and discharges the hydraulic fluid of the pump chamber 40 located in the discharge region 33B is formed.

  The pump chamber 40 sucks the working oil through the suction port 51A in the suction region 32A and discharges the sucked working oil through the discharge port 52A in the discharge region 33A and then into the suction region 32B in the process of the rotor 10 making one rotation. Then, the working oil is sucked through the suction port 51B, and the sucked working oil is discharged through the discharge port 52B in the discharge region 33B. Thus, the pump chamber 40 performs the suction and discharge of the hydraulic oil twice in the process in which the rotor 10 rotates once.

  Each pump chamber 40 in the range from the suction region 32A to the discharge region 33A constitutes a main pump chamber 41, and each pump chamber 40 in the range from the suction region 32B to the discharge region 33B constitutes a sub pump chamber 42. Therefore, the main pump chamber 41 sucks the hydraulic oil through the suction port 51A and discharges the hydraulic oil through the discharge port 52A. Further, the sub pump chamber 42 sucks the working oil through the suction port 51B and discharges the working oil through the discharge port 52B.

  In the vane pump 100, the volume of the main pump chamber 41 and the volume of the sub pump chamber 42 are set to be substantially the same so that the discharge flow rates of hydraulic oil from the main pump chamber 41 and the sub pump chamber 42 are equal. Yes.

  As shown in FIG. 1, two positioning pins 4 are erected and coupled to the side plate 3. The positioning pin 4 is inserted into the engagement hole of the pump cover while being inserted through the through hole 34 formed in the cam ring 30. These positioning pins 4 restrict relative rotation between the pump cover and the side plate 3 with respect to the cam ring 30. As a result, the suction areas 32A and 32B of the cam ring 30 and the suction ports 51A and 51B of the pump cover are positioned, and the discharge areas 33A and 33B of the cam ring 30 and the discharge ports 52A and 52B of the side plate 3 are positioned.

  Next, the hydraulic circuit of the vane pump 100 will be described with reference to FIGS.

  FIG. 2 shows a full discharge state in which the hydraulic oil discharged from the main pump chamber 41 and the sub pump chamber 42 is supplied to the hydraulic device 110. FIG. 3 shows a semi-discharge state in which the hydraulic oil discharged from the main pump chamber 41 is supplied to the hydraulic equipment 110. 2 and 3, thin arrows indicate the flow direction of hydraulic oil.

  The main pump chamber 41 communicates with the tank 120 that stores hydraulic oil via the main suction passage 60. One end of the main suction passage 60 is connected to a tank 120 that stores hydraulic oil, and the other end of the main suction passage 60 is connected to a suction port 51A of the pump cover.

  The main pump chamber 41 communicates with the hydraulic equipment 110 through the main discharge passage 70. One end of the main discharge passage 70 is connected to the discharge port 52A of the pump cover, and the other end of the main discharge passage 70 is connected to the hydraulic oil inflow portion of the hydraulic device 110.

  The sub pump chamber 42 communicates with the tank 120 via the sub suction passage 80. The sub suction passage 80 is a passage that branches from the branch portion 61 of the main suction passage 60. One end of the sub suction passage 80 is connected to the branch portion 61 of the main suction passage 60, and the other end of the sub suction passage 80 is connected to the suction port 51B of the pump cover.

  The sub pump chamber 42 communicates with the hydraulic device 110 through the sub discharge passage 90. The sub-discharge passage 90 is a passage that joins the merging portion 71 of the main discharge passage 70. One end of the sub discharge passage 90 is connected to the discharge port 52 </ b> B of the pump cover, and the other end of the sub discharge passage 90 is connected to the merging portion 71 of the main discharge passage 70.

  The hydraulic oil discharged from the main pump chamber 41 of the vane pump 100 is always supplied to the hydraulic equipment 110 through the main discharge passage 70. On the other hand, the hydraulic oil discharged from the sub pump chamber 42 of the vane pump 100 is selectively supplied to the hydraulic equipment 110 by the spool valve 200 interposed in the sub discharge passage 90.

  The spool valve 200 is a valve mechanism configured to be able to switch the flow path of hydraulic oil in the sub discharge passage 90 and the main suction passage 60. The spool valve 200 is interposed in the main suction passage 60 on the downstream side of the sub discharge passage 90 and the branch portion 61.

  The spool valve 200 includes a spool 210 that moves according to the hydraulic pressure acting on both ends and can change the flow path of the hydraulic oil, a first pressure chamber 221 that is defined facing one end of the spool 210, A second pressure chamber 222 defined toward the end, and a spring 230 that is accommodated in the second pressure chamber 222 and biases the spool 210 in a direction of enlarging the volume of the second pressure chamber 222.

  The hydraulic oil adjusted to a predetermined pressure is always guided to the first pressure chamber 221, and the hydraulic oil adjusted to the predetermined pressure and the tank pressure are selectively guided to the second pressure chamber 222 by the operation of the electromagnetic valve 240. It is burned.

  As shown in FIG. 2, when hydraulic oil adjusted to a predetermined pressure is guided to the second pressure chamber 222 by the operation of the electromagnetic valve 240, the pressure of the first pressure chamber 221, the pressure of the second pressure chamber 222, Are substantially the same, and the spool 210 is moved in the direction of expanding the volume of the second pressure chamber 222 by the biasing force of the spring 230.

  In this state, the main pump chamber 41 sucks the working oil through the main suction passage 60 and discharges the working oil to the hydraulic device 110 through the main discharge passage 70. The sub pump chamber 42 sucks the working oil through the main suction passage 60 and the sub suction passage 80 on the upstream side of the branching portion 61, and discharges the working oil to the hydraulic device 110 through the sub discharge passage 90. In this manner, the vane pump 100 is fully discharged, and the entire amount of hydraulic oil discharged from the main pump chamber 41 and the sub pump chamber 42 is supplied to the hydraulic device 110.

  On the other hand, as shown in FIG. 3, when the tank pressure is guided to the second pressure chamber 222 by the operation of the electromagnetic valve 240, the pressing force acting on the spool 210 due to the pressure of the first pressure chamber 221 is The sum of the pressing force acting on the spool 210 due to the pressure of the second pressure chamber 222 and the urging force of the spring 230 increases, and the spool 210 moves in a direction in which the volume of the second pressure chamber 222 contracts.

  In this state, the spool 210 of the spool valve 200 blocks the main suction passage 60 on the downstream side of the branch portion 61 so that the tank 120 and the main pump chamber 41 do not communicate with each other, and the sub discharge passage 90 extends from the sub pump chamber 42. The discharged hydraulic oil is connected to the main suction passage 60 so as to be supplied to the main pump chamber 41. As a result, the sub pump chamber 42 sucks hydraulic oil through the main suction passage 60 and the sub suction passage 80 on the upstream side of the branch portion 61, and enters the main pump chamber 41 through the sub discharge passage 90 and the main suction passage 60. Supply hydraulic oil. The main pump chamber 41 discharges the hydraulic oil supplied from the sub pump chamber 42 to the hydraulic equipment 110 through the main discharge passage 70. In this manner, the vane pump 100 is in a semi-discharge state, and the hydraulic oil discharged from the main pump chamber 41 is supplied to the hydraulic device 110.

  In the low engine rotation speed range, the rotation speed of the rotor 10 is low, so the discharge flow rate of the hydraulic oil discharged from the vane pump 100 is small. Therefore, the spool valve 200 is controlled so that the vane pump 100 is in a full discharge state so that sufficient hydraulic oil is supplied from the vane pump 100 to the hydraulic equipment 110.

  On the other hand, in the high engine rotation speed range, the rotation speed of the rotor 10 is high, so that the discharge flow rate of the hydraulic oil discharged from the vane pump 100 is large. Therefore, the spool valve 200 is controlled so that the vane pump 100 is in a semi-discharge state so that excessive hydraulic oil is not supplied from the vane pump 100 to the hydraulic equipment 110.

  When the rotor 10 is at a high rotational speed, the vane pump 100 sucks the working oil in the tank 120 by the sub pump chamber 42, guides the sucked working oil to the main pump chamber 41, and supplies the working oil from the main pump chamber 41 to the hydraulic device 110. Supply. In such a case, the suction flow rate in the vane pump 100 that sucks the hydraulic oil by the sub pump chamber 42 is smaller than the suction flow rate in the conventional vane pump that sucks the hydraulic oil by both the main pump chamber and the sub pump chamber.

  As described above, in the vane pump 100, the spool valve 200 is switched based on the engine rotation speed, that is, the rotation speed of the rotor 10. Note that when the hydraulic device 110 requires almost no hydraulic fluid even in the low engine speed range, the driving torque in the vane pump 100 is reduced by controlling the spool valve 200 so that the vane pump 100 is in a semi-discharge state. It becomes possible to do.

  According to the vane pump 100 of this embodiment described above, the following effects can be obtained.

  At the time of high rotational speed of the rotor 10, in the vane pump 100, the spool valve 200 blocks the main suction passage 60 on the downstream side of the branch portion 61 so that the tank 120 and the main pump chamber 41 do not communicate with each other. The sub discharge passage 90 is connected to the main suction passage 60 so that the hydraulic oil discharged from the chamber 42 is supplied to the main pump chamber 41. Since the vane pump 100 sucks the hydraulic oil in the tank 120 only by the sub pump chamber 42 at the high rotation speed of the rotor 10, the suction flow rate of the hydraulic oil in the vane pump 100 is the conventional vane pump that sucks hydraulic oil by both the main pump chamber and the sub pump chamber. Less than the suction flow rate. Therefore, it is possible to prevent cavitation from occurring in the main suction passage 60 in the vicinity of the connection position with the tank 120 at the time of the high rotation speed of the rotor 10. As a result, it is possible to prevent defective suction of the hydraulic oil in the vane pump 100 and to stably supply the hydraulic oil from the vane pump 100 to the hydraulic equipment 110.

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

  For example, the vane pump 100 of the present embodiment is configured such that the volume of the main pump chamber 41 and the volume of the sub pump chamber 42 are substantially the same, but the volume of the sub pump chamber 42 is the same as that of the main pump chamber 41 as shown in FIG. You may comprise so that it may become slightly larger than a volume.

  Referring to FIG. 4, the rotor 10 of the vane pump 100 is disposed such that the rotation center of the rotor 10 is shifted toward the main pump chamber 41 with respect to the axis of the cam ring 30. As a result, the maximum distance d1 between the cam surface 31 and the outer peripheral surface of the rotor 10 in the sub pump chamber 42 is larger than the maximum distance d2 between the cam surface 31 and the outer peripheral surface of the rotor 10 in the main pump chamber 41. The volume becomes larger than the volume of the main pump chamber 41.

  Since the hydraulic oil in the main pump chamber 41 and the sub pump chamber 42 slightly leaks from the minute gaps between the pump components, the discharge flow rate of the hydraulic oil discharged from the main pump chamber 41 and the sub pump chamber 42 is the main pump. This is less than the supply flow rate of hydraulic oil supplied to the chamber 41 and the sub pump chamber 42. Therefore, when the volume of the main pump chamber 41 and the volume of the sub pump chamber 42 are substantially the same, when the vane pump 100 is in a semi-discharge state, the hydraulic oil discharged from the sub pump chamber 42 is supplied to the main pump chamber 41. The supply flow rate of hydraulic oil to the main pump chamber 41 may be insufficient. However, if the volume of the sub pump chamber 42 is larger than the volume of the main pump chamber 41, the discharge flow rate of the hydraulic oil discharged from the sub pump chamber 42 can be compensated even if the hydraulic oil leaks slightly from the sub pump chamber 42, Even in the half discharge state, the supply flow rate of the hydraulic oil to the main pump chamber 41 does not become insufficient. Therefore, it becomes possible to supply hydraulic oil from the vane pump 100 to the hydraulic equipment 110 more stably.

  The vane pump according to the present invention can be applied to a hydraulic power supply source such as a power steering device or a transmission of a vehicle.

DESCRIPTION OF SYMBOLS 100 Vane pump 1 Drive shaft 10 Rotor 20 Vane 30 Cam ring 31 Cam surface 40 Pump chamber 41 Main pump chamber 42 Sub pump chamber 60 Main suction passage 61 Branching portion 70 Main discharge passage 71 Merge portion 80 Sub suction passage 90 Sub discharge passage 110 Hydraulic equipment 120 Tank 200 Spool valve 210 Spool 221 First pressure chamber 222 Second pressure chamber

Claims (4)

A rotor coupled to a drive shaft, a plurality of vanes provided so as to be movable in a radial direction with respect to the rotor, a cam ring having an inner peripheral surface on which a tip of the vane is slidable, the vane, the rotor, And a main pump chamber and a sub pump chamber defined by the cam ring, and a vane pump for supplying a working fluid from the main pump chamber and the sub pump chamber to a hydraulic device,
A tank for storing a working fluid;
A main suction passage communicating the tank and the main pump chamber;
A main discharge passage communicating the main pump chamber and the hydraulic device;
A sub suction passage that branches off from a branch portion of the main suction passage and communicates the tank and the sub pump chamber;
A sub-discharge passage communicating the sub-pump chamber and the hydraulic device;
The main suction passage on the downstream side of the branch portion is blocked so that the tank and the main pump chamber do not communicate with each other, and the working fluid discharged from the sub pump chamber is supplied to the main pump chamber. A vane pump comprising: a valve mechanism capable of switching the flow path of the working fluid by connecting the sub-discharge passage to the main suction passage.   The vane pump according to claim 1, wherein the sub pump chamber is configured to have a larger volume than the main pump chamber.   3. The vane pump according to claim 2, wherein the rotor is disposed such that a rotation center is shifted toward a main pump chamber with respect to an axis of the cam ring.   The said valve mechanism is a spool valve which has a spool which can change the flow path of the working fluid in the said main suction passage and the said sub discharge passage according to the rotation state of the said rotor. 4. The vane pump according to any one of 3.

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