JP2015169156A - Variable capacity type vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable capacity type vane pump capable of suppressing insufficient lubrication of a driving shaft.SOLUTION: Between the inside surface of an end wall part 10b of a pump body 15 and the pressure reception surface of a pressure plate 23, a first seal member S1 partitioning a high pressure chamber 33 and a first shaft hole 35a and a second seal member S2 partitioning the high pressure chamber 33 and first shaft hole 35a and a first low pressure chamber 27a are provided, and thereby negative pressure with suction action is blocked by the first and second seal members S1, S2, so that the negative pressure is prevented from affecting working fluid in the first shaft hole 35a.

Description

  The present invention relates to a variable displacement vane pump applied to, for example, a hydraulic pressure supply source of an automatic transmission of an automobile.

  As a conventional variable displacement vane pump applied to an automatic transmission of an automobile, for example, the one described in Patent Document 1 below is known.

  The variable displacement vane pump includes a cylindrical pump housing having a pump element accommodating portion therein, a drive shaft inserted and supported by the pump housing, a rotor driven to rotate by the drive shaft, and an outer peripheral portion of the rotor A plurality of vanes provided so as to be movable in and out, and a cam ring that is accommodated on the outer circumferential side of the rotor so as to be eccentrically movable with respect to the axis of the drive shaft, and that defines a plurality of pump chambers in the circumferential direction together with the rotor and the plurality of vanes. The discharge flow rate is made variable by changing the volume of each pump chamber based on the eccentric amount of the cam ring.

JP 2012-163040 A

  Here, the conventional variable displacement vane pump is mounted so as to be immersed in the working fluid inside the automatic transmission, while the high-pressure part side is liquid-tightly separated. It is configured to be able to communicate with the bearing portion of the pump housing via an axial clearance between the pump housing and the rotor, and the hydraulic fluid is allowed to leak outside the pump.

  However, from such a configuration, during the suction operation, the hydraulic fluid used for bearing lubrication in the bearing portion is sucked up by the negative pressure generated as the volume of the pump chamber increases due to the rotation of the rotor. There is a risk of causing problems such as sliding wear of the drive shaft due to shortage.

  The present invention has been devised by paying attention to such a technical problem, and provides a variable displacement vane pump capable of suppressing insufficient lubrication of a drive shaft.

  The present invention provides a drive shaft side seal member that separates the high pressure chamber and the bearing portion between the one end wall of the pump element housing portion and the pressure receiving surface of the pressure plate, and the high pressure chamber, the bearing portion, and the low pressure chamber. And a low-pressure chamber side sealing member formed.

  According to the present invention, since the low-pressure chamber and the bearing portion are separated from each other, there is no possibility that the hydraulic fluid in the bearing portion is sucked up by the negative pressure due to the suction action, and this serves to suppress insufficient lubrication of the drive shaft. The

1 is a front view of a variable displacement vane pump according to the present invention. It is the sectional view on the AA line of FIG. 1 which shows 1st Embodiment of this invention. FIG. 3 is a sectional view taken along line B-B in FIG. 2. It is CC sectional view taken on the line of FIG. It is the figure which looked at the pump body shown in FIG. 2 from the joint surface side with a pump cover. (A) is the figure which assembled | attached the 1st bearing to the pump body, (b) is the figure which assembled the 2nd bearing to the pump cover. FIG. 6 is a view corresponding to FIG. 5 showing a modification of the first embodiment of the present invention. FIG. 6 is a view corresponding to FIG. 5 showing a second embodiment of the present invention.

Hereinafter, each embodiment of the variable displacement vane pump according to the present invention will be described in detail with reference to the drawings. In the following embodiment, the variable displacement vane pump is applied to an automatic transmission (CVT) of a vehicle as in the prior art.
[First Embodiment]
1 to 6 show a first embodiment of a variable displacement oil pump according to the present invention. This variable displacement vane pump (hereinafter simply referred to as “pump”) is shown in FIGS. 1 to 3. In addition, a substantially cylindrical pump housing 11 having a pump element housing portion 10 therein is inserted and supported along the axial direction of the pump housing 11, and is rotationally driven based on a driving force transmitted from an engine (not shown). A drive shaft 12, an annular adapter ring 13 fitted to the peripheral wall of the pump element accommodating portion 10, and an axis of the drive shaft 12 on the inner peripheral side of the adapter ring 13 (rotation center of the rotor 21 described later) An annular cam ring 14 accommodated eccentrically with respect to Q, and accommodated and arranged on the inner peripheral side of the cam ring 14, and rotated later in the counterclockwise direction in FIG. Comprises a pumping element that performs an action, the control valve 50 for controlling the discharge flow rate of the working fluid (so-called specific discharge amount) discharged by the pump element rotates 1, a.

  The pump housing 11 is a pump body 15 that is a substantially bottomed cylindrical first housing constituted by a cylindrical portion 10a and an end wall portion 10b as a bottom portion that closes one axial end of the cylindrical portion 10a. And a pump cover 16 that is a second housing that closes the opening at the other end of the cylindrical portion 10a. The pump cover 11 and the pump cover 16 communicate with the pump body 11 and the outer periphery of the pump cover 16. It is fastened by a bolt 20 via a plurality of formed fastening portions 15a, 16a.

  The adapter ring 13 has a pin member 17 that supports the swinging of the cam ring 14 held in an arc-shaped groove formed in the inner peripheral surface of the upper end portion. A seal member 18 is provided on the inner peripheral surface of the adapter ring 13 at a position substantially opposite to the pin member 17 in the radial direction. The adapter member 13 and the cam ring 14 are formed by the seal member 18 and the pin member 17. The first fluid pressure chamber P1 and the second fluid pressure chamber P2 used for swing control of the cam ring 14 are separated from each other in the radial direction.

  The cam ring 14 is made of a ferrous metal sintered material, and an engagement groove having a circular cross section formed in a notch in the outer peripheral portion thereof is engaged with the pin member 17, whereby the first fluid pressure chamber P 1 side is formed. Alternatively, the cam ring 6 is supported on the second fluid pressure chamber P2 side in a swingable manner, and the cam ring 6 moves to the first fluid pressure chamber P1 side based on the urging force of the coil spring 19 disposed on the second fluid pressure chamber P2 side. The rotor 21 is always biased in the direction in which the amount of eccentricity relative to the rotation center Q of the rotor 21 (hereinafter simply referred to as “the amount of eccentricity”) becomes maximum.

  The pump element is spline-coupled to the outer periphery of the drive shaft 12 so as to be integrally rotatable. The rotor 21 is rotatably accommodated on the inner peripheral side of the cam ring 14, and the slots are radially formed in the outer peripheral portion of the rotor 21. 21a, and a plurality of rectangular plate-like vanes 22 that are accommodated and held so as to be able to move in and out. The substantially disc-shaped pressure plate 23 is disposed adjacent to the end wall portion 10b at the inner end portion of the pump element accommodating portion 10. And the pump cover 16.

  A back pressure groove having a substantially circular cross section is provided along the axial direction at the inner end of each slot 21a of the rotor 21. The back pressure groove and the base end of the vane 22 define the back pressure groove. The vane 22 is ejected by the internal pressure of the back pressure chamber 24 formed and the centrifugal force accompanying the rotation of the rotor 21. With this structure, each vane 22 jumps out of each slot 21 a as the rotor 21 rotates, and the tip of each vane 22 is always in sliding contact with the inner peripheral surface of the cam ring 14. A plurality of pump chambers 30 are defined by the pair of adjacent vanes 22 and 22, the pressure plate 23 and the pump cover 16, and the volume of each pump chamber 30 is increased or decreased by swinging the cam ring 14. It has become.

  Further, as shown in FIGS. 2 and 4, each pump chamber 30 is provided on one side surface of the pressure plate 23, which is a surface facing the rotor 21, and on the inner surface of the pump cover 16 as the rotor 21 rotates. A pair of first suction port 25a and second suction port 25b, which are notched in an arcuate groove shape, are provided along the circumferential direction in a region where the internal volume of the gas pipe gradually increases (hereinafter referred to as "suction region"). It has been. The first suction port 25a is connected to the cylindrical portion 10a through a suction hole 26 formed through a predetermined position in the circumferential direction and through a first low pressure chamber 27a formed in the inner surface of the end wall portion 10b. The second suction port 25b is connected to the perforated suction port 28, and the second low pressure chamber 27b is formed in the inner surface of the pump cover 16, and the second low pressure chamber 27b and the suction port 28 are formed. Are connected to the suction port 28 through a series of passages that communicate with each other, so that hydraulic fluid sucked from an oil pan (not shown) is guided through the suction port 28. It is like that. In the present embodiment, the suction hole 26 and the first low-pressure chamber 27a, the second low-pressure chamber 27b, and the communication passage 29 constitute a suction passage according to the present invention.

  Here, in the pump according to the present embodiment, since the suction port 28 is formed in the cylindrical portion 10a of the pump body 15, the suction port 28 is compared with the case where the suction port 28 is provided in the pump cover 16. The opening area of the port 28 can be secured relatively large, and the suction efficiency of the pump can be improved.

  Further, as shown particularly in FIGS. 2 and 5, the one side surface of the pressure plate 23 and the inner side surface of the pump cover 16 are substantially axially positioned relative to the first and second suction ports 25a and 25b. In the same manner as the first and second suction ports 25a and 25b, a notch is formed in a region where the internal volume of each pump chamber 30 gradually decreases with the rotation of the rotor 21 (hereinafter referred to as "discharge region"). The formed substantially arcuate groove-shaped first discharge port 31a and second discharge port 31b are provided along the circumferential direction. The first discharge port 31a communicates with a substantially arc-shaped high-pressure chamber 33 that is formed in the inner surface of the end wall portion 10b through a discharge hole 32 that is formed through a predetermined position in the circumferential direction. The high pressure chamber 33 is discharged outside the pump (not shown) through a discharge passage (not shown) provided inside the pump body 15.

  Further, as shown in FIGS. 2 and 6, a drive shaft insertion hole 34 through which the drive shaft 12 is inserted is formed through the central portion of the pressure plate 23, and pumps in the pump body 15 and the pump cover 16 are formed. A first shaft hole 35 a and a second shaft hole 35 b for supporting the drive shaft 12 are formed through the center of the element housing portion 10. The first and second shaft holes 35 a and 35 b are both set to have a slightly larger inner diameter than the drive shaft 12, and the first bearing B 1 and the second bearing B 2, which are plain bearings, are between the drive shaft 12. In addition to being interposed, the hydraulic fluid interposed between the bearings B1 and B2 and the drive shaft 12 can lubricate the two. Here, a spiral groove 36 is formed in the inner peripheral surface of each of the bearings B1 and B2 so that the working fluid can be discharged to the outside of the pump in sliding contact with the drive shaft 12.

  Further, a discharge passage 37 is formed through the outer end portion of the first shaft hole 35a so as to communicate the first shaft hole 35a with the outside of the pump. The delivered hydraulic fluid is discharged out of the pump. The discharge passage 37 is provided so as to be inclined from the outer end of the first shaft hole 35a toward the vertically lower side, and the opening is in the hydraulic fluid stored in the oil pan (not shown). It is configured to be dipped in.

  Further, as shown in FIG. 2, one side surface of the pressure plate 23 and the inner surface of the pump cover 16 are arcuate groove-shaped first regions in predetermined ranges in the circumferential direction facing the back pressure chambers 24 in the discharge region. The first back pressure port 38a and the second back pressure port 38b are notched. The discharge pressure is guided from the high pressure chamber 33 to the first back pressure port 38a through an introduction hole (not shown), and the discharge pressure is guided to the second back pressure port 38b through the back pressure chamber 24. It has become.

  Further, on the inner surface of the pump cover 16, there is an arc groove-like lubrication groove 39 that serves for frictional lubrication with the rotor 21 by guiding the discharge pressure to a predetermined range in the circumferential direction facing the back pressure chamber 24 in the suction area. Notches are formed. Note that, similarly to the second back pressure port 38b, the discharge pressure is guided to the lubrication groove 39 through the back pressure chamber 24.

  Further, as shown in FIGS. 2 and 5, a first seal groove 41 as an annular drive shaft side seal groove is formed in the inner surface of the end wall portion 10b in the outer peripheral area of the first shaft hole 35a. In addition, a second seal groove 42 as an oval low pressure chamber side seal groove is formed in the outer peripheral area of the first low pressure chamber 27 a, and the both seal grooves 41, 42 are separated from each other by a partition wall 43. The structure is divided into two. Then, in the first and second seal grooves 41 and 42, a first seal member S1 as a drive shaft side seal member and a second seal member S2 as a low pressure chamber side seal member having corresponding shapes are fitted. By attaching, the first shaft hole 35a and the first low pressure chamber 27a, which are at a low pressure, are separated from the high pressure chamber 33, and the first shaft hole 35a and the first low pressure chamber 27a are in direct communication with the outside of the pump. Are separated.

  As shown in FIG. 3, the control valve 50 includes a spool valve body 52 slidably received in a valve hole 51 formed in the pump body 15, and one end side of the valve hole 51 (in FIG. Between the plug 53 and the spool valve body 52, and the valve spring 54 for urging the spool valve body 52 in the left direction in FIG. 3 and the other end side of the valve hole 51 are closed. In addition, a push rod (not shown) is mainly composed of a solenoid 55 disposed so as to be linked to the spool valve body 52.

  In the control valve 50, the discharge pressure which is the hydraulic pressure upstream of the metering orifice (not shown) is supplied to the first control chamber R1 on the solenoid 55 side which is separated by the first land portion 52a of the spool valve body 52. And the hydraulic pressure downstream of the metering orifice (not shown) is guided to the second control chamber R2 on the plug 53 side separated by the second land portion 52b of the spool valve body 52. In addition, the axial position of the spool valve body 52 is controlled by the differential pressure across the metering orifice and the urging force of the valve spring 54, thereby providing an eccentricity control of the cam ring 14. The low-pressure chamber R0 defined between the land portions 52a and 52b is configured to communicate with the outside of the pump through a communication hole (not shown) so as to be maintained at a low pressure equivalent to the suction pressure. It has become.

  Specifically, when the pressure difference between the first control chamber R1 and the second control chamber R2 is relatively small and the spool valve body 52 is positioned on the solenoid 55 side, the first fluid pressure is passed through the first communication passage 56a. The chamber P1 and the low pressure chamber R0 communicate with each other, and the second control chamber R2 and the second fluid pressure chamber P2 communicate with each other via the second communication passage 56b. As a result, the cam ring 14 has a fluid pressure in the second fluid pressure chamber P2. And the biasing force of the coil spring 19 are controlled to the maximum eccentric position, and the pump discharge flow rate becomes maximum. On the other hand, when the pressure difference between the first control chamber R1 and the second control chamber R2 increases and the spool valve body 52 moves toward the plug 53 against the urging force of the valve spring 54, the first control passage R1 passes through the first communication passage 56a. As a result, the first control chamber R1 and the first fluid pressure chamber P1 communicate with each other, and the low pressure chamber R0 and the second fluid pressure chamber P2 communicate with each other through the second communication passage 56b. Based on the pressure in the chamber P1, the swinging control is performed so that the amount of eccentricity decreases against the biasing force of the coil spring 19, and the pump discharge flow rate decreases.

  Hereinafter, a characteristic operation effect of the variable displacement pump according to the present embodiment will be described with reference to FIG.

  As described above, the oil pump for the automatic transmission (CVT) is provided so as to be housed inside the automatic transmission. Therefore, the first and second bearings B1 and B2 of the pump housing 11 and the drive shaft 12 are provided. The inside and outside of the pump are allowed to communicate through the first and second radial gaps C1 and C2 interposed therebetween. Thus, conventionally, due to such a communication state, the working fluid in the first radial gap C1 is caused to flow between the inner side surface of the end wall portion 10b and the other side surface of the pressure plate 23 by the negative pressure generated based on the suction action of the pump. Is sucked out to the suction side (the first suction port 25a side) through the axial gap C3, which causes a problem that sufficient lubrication between the first bearing B1 and the drive shaft 12 cannot be secured.

  Therefore, in the pump according to the present embodiment, the first seal member S1 and the second seal member S2 separate the peripheral region of the first shaft hole 35a from the peripheral region of the first low-pressure chamber 27a. As a result, the negative pressure generated by the suction action is blocked by the first and second seal members S1 and S2 (particularly the second seal member S2), so that the hydraulic fluid in the first radial gap C1 is moved to the suction side. The inconvenience of being sucked out can be avoided, and the lack of lubrication can be solved.

  In addition, in this embodiment, the first and second seal members S1, S2 are configured as separate seal members, whereby the shapes of the seal members S1, S2 can be simplified, and both the seal members S1, S2 are used. Since the discharge pressure can be guided to the groove portion 40 (see FIG. 5) formed therebetween, and the insufficient pressure of the pressure plate 23 in the low pressure region can be compensated by the discharge pressure, the deformation of the pressure plate 23 is prevented. It is also used for suppression.

  In addition, since each of the seal members S1 and S2 is fitted in a separate seal groove 41 and 42, there is an advantage that the retainability of the seal members S1 and S2 can be improved.

  In addition, since the first shaft hole 35a and the outside of the pump are directly communicated with each other through the discharge passage 37, the driving shaft is compared with the case where the hydraulic fluid leaked from each pump chamber 30 is returned to the suction side. 12 is used to suppress negative pressure around 12. Moreover, since the discharge passage 37 is formed vertically downward from the first shaft hole 35a, the outer end portion of the discharge passage 37 can be easily immersed in the hydraulic fluid of the oil pan (not shown). Suction of outside air through the discharge passage 37 is suppressed, so that the pump efficiency can be improved and the contamination discharge property in the working fluid can be improved.

  Further, since the spiral grooves 36 that can discharge the working fluid to the outside of the pump are formed on the inner peripheral surfaces of the first and second bearings B1 and B2 in accordance with the sliding contact with the drive shaft 12, respectively, the driving of the pump In this case, the hydraulic fluid in the first and second radial gaps C1 and C2 can be positively discharged to the outside of the pump via the spiral groove 36. The suction of hydraulic fluid through the first and second radial gaps C1 and C2 based on the accompanying negative pressure can be more effectively suppressed.

In the case of the present embodiment, the inner surface of the pump cover 16 is a circumferential range corresponding to the suction region, and is located at a position facing the back pressure chamber 24 on the inner peripheral side of the second low pressure chamber 27b. By providing the lubrication groove 39, the negative pressure from the second low-pressure chamber 27b side can be blocked by the discharge pressure guided to the lubrication groove 39 on the pump cover 16 side, and the negative pressure passes through the axial gap C3. There is also a merit that it is possible to avoid the problem of acting on the hydraulic fluid in the two radial gap C2.
(Modification)
FIG. 7 shows a modification of the first embodiment, in which the first seal groove is formed so that the area of the circumferential range corresponding to the discharge region is relatively large with respect to the hole edge of the first shaft hole 35a. By providing 41, a low-pressure region enlarged portion 44 that allows introduction of a low pressure in a relatively wide range is formed at the hole edge of the first shaft hole 35a corresponding to the discharge region.

As described above, by expanding the low pressure region in the discharge region by the low pressure region expanding portion 44, the pressing force of the pressure plate 23 due to the discharge pressure interposed in the axial gap C3 in the discharge region can be reduced. The problem that the pressing force becomes excessive can be suppressed, and the deformation of the pressure plate 23 is suppressed.
[Second Embodiment]
FIG. 8 shows a second embodiment of the variable displacement vane pump according to the present invention. The difference from the first embodiment is that the partition wall 43 is deleted and the first seal groove 41 and the second seal pump are removed. The seal groove 42 is configured as a series of seal grooves 45, and the first seal member S1 and the second seal member S2 are configured as an integral seal member S0.

  As described above, in the present embodiment, since the series of seal grooves 45 are configured, the space for the partition wall 43 can be omitted compared to the first embodiment in which the partition wall 43 is provided. The opening area of the first suction port 25a can be enlarged, and the pump suction efficiency is improved.

  Furthermore, since the first and second seal members S1 and S2 configured as separate members in the first embodiment are configured as the integral seal member S0, the number of parts of the pump can be reduced, and the pump Productivity can be improved.

  The present invention is not limited to the configuration of each of the above embodiments. For example, the positions of the suction ports 25a and 25b and the discharge ports 31a and 31b, the routing of the passages therefor, the control method of the cam ring 14, and the like. In addition to the detailed configuration that is not directly related to the configuration of the present invention, the position and shape of the seal groove 41, 42, etc., such as the specific configuration, are also directly related to the configuration of the present invention. It can be freely changed according to the specifications of the engine to be applied without departing from the scope of the above.

  Hereinafter, technical ideas other than those described in the scope of claims understood from the respective embodiments will be described.

(A) In the variable displacement vane pump according to claim 2,
A variable displacement vane pump, wherein the pump housing is provided with a discharge passage for discharging the hydraulic fluid leaked around the drive shaft to the outside.

  Such a configuration serves to suppress negative pressure in the space around the drive shaft, compared to when the working fluid leaked around the drive shaft is recirculated to the suction side.

(B) In the variable displacement vane pump according to (a),
The variable displacement vane pump is characterized in that the discharge passage has an outer end arranged vertically below an inner end.

  With this configuration, there is a high possibility that the outer end portion enters below the hydraulic fluid level of the oil pan, so that suction of outside air is suppressed and pump efficiency can be improved. Further, by setting the outer end portion of the discharge passage vertically downward, it is also used to improve the discharge of contamination in the hydraulic fluid.

(C) In the variable displacement vane pump according to claim 1,
The suction passage is configured to communicate with the suction region from both axial sides,
A variable displacement vane pump characterized in that a lubrication groove for sliding lubrication of the rotor is provided by guiding discharge pressure at a position facing one end wall of the pump element housing portion.

  By adopting such a configuration, it is possible to avoid a problem that the negative pressure on the suction region side affects the space around the drive shaft due to the discharge pressure guided to the lubrication groove.

(D) In the variable displacement vane pump according to claim 1,
The variable displacement vane pump, wherein the drive shaft side seal member and the low pressure chamber side seal member are formed separately from each other.

  By adopting such a configuration, there is an advantage that the shape of each seal member can be simplified as compared with a case where a part of both seal members are connected and configured integrally.

(E) In the variable displacement vane pump described in (d) above,
A variable displacement vane pump, characterized in that a high-pressure introduction groove for guiding a discharge pressure is provided between the drive shaft side seal member and the low pressure chamber side seal member on one end wall of the pump element accommodating portion.

  By adopting such a configuration, it becomes possible to compensate for the insufficient pressing force of the pressure plate in the low pressure region surrounded by the drive shaft side seal member and the low pressure chamber side seal member by the discharge pressure guided by the high pressure introduction groove. The deformation of the plate can be suppressed.

(F) In the variable displacement vane pump according to (d),
A drive shaft side seal groove into which the drive shaft side seal member is fitted is formed on one end wall of the pump element housing portion, and the low pressure chamber side seal member is separated from the drive shaft side seal groove. A variable displacement vane pump characterized in that a low-pressure chamber side sealing groove to be fitted is formed.

  By setting it as this structure, since each sealing member is each hold | maintained by a seal groove, it uses for the improvement of the holding property of each said sealing member.

(G) In the variable displacement vane pump described in (d) above,
A drive shaft side seal groove into which the drive shaft side seal member is fitted is formed at one end wall of the pump element housing portion, and a low pressure chamber side seal groove into which the low pressure chamber side seal member is fitted is formed. ,
The variable displacement type wherein the drive shaft side seal groove and the low pressure chamber side seal groove are continuously provided in a region where the drive shaft side seal member and the low pressure chamber side seal member are adjacent to each other. Vane pump.

  By adopting such a configuration, the space for the partition wall can be omitted as compared with the case where a partition wall for separating both seal grooves is provided in a region where both seal members are adjacent to each other, and this can increase the opening area of the suction port. Garage.

(H) The variable displacement vane pump according to claim 1,
The variable displacement vane pump, wherein the drive shaft side seal member and the low pressure chamber side seal member are integrally formed so as to be connected to each other.

  With such a configuration, the number of parts of the pump can be reduced, and productivity can be improved.

(I) In the variable displacement vane pump according to claim 1,
The drive-side seal member is formed so that an area of a low-pressure region formed between the bearing portion and the radial direction is larger on the discharge region side than on the suction region side. Capacity type vane pump.

  By adopting such a configuration, it is possible to suppress a problem that the pressing force of the pressure plate becomes excessive on the discharge region side, which is used for suppressing deformation of the pressure plate.

(J) In the variable displacement vane pump according to claim 1,
The drive shaft is supported by a plain bearing provided so as to surround the outer periphery of the drive shaft,
On the inner peripheral surface of the plain bearing, a spiral is configured such that hydraulic fluid interposed between the drive shaft and the drive shaft in a radial direction moves in a direction away from the pump element housing portion by relative rotation with the drive shaft. A variable displacement vane pump characterized in that a groove is formed.

  With such a configuration, it is possible to positively discharge the hydraulic fluid to the outside of the pump housing, and thereby it is possible to more effectively suppress the suction of the hydraulic fluid around the drive shaft.

(K) In the variable displacement vane pump according to claim 4,
A variable displacement vane pump characterized in that the pump element housing portion and the outside of the pump housing can communicate with each other through a radial clearance between the pump housing and the drive shaft.

  With this configuration, the number of pump parts can be reduced, and productivity and cost can be reduced.

(L) In the variable displacement vane pump according to (k),
A variable displacement vane pump, wherein the pump housing is provided with a discharge passage for discharging the hydraulic fluid leaked around the drive shaft to the outside.

  Such a configuration serves to suppress negative pressure in the space around the drive shaft, compared to when the working fluid leaked around the drive shaft is recirculated to the suction side.

(M) In the variable displacement vane pump according to (l),
The variable displacement vane pump is characterized in that the discharge passage has an outer end arranged vertically below an inner end.

  With this configuration, there is a high possibility that the outer end portion enters below the hydraulic fluid level of the oil pan, so that suction of outside air is suppressed and pump efficiency can be improved. Further, by setting the outer end portion of the discharge passage vertically downward, it is also used to improve the discharge of contamination in the hydraulic fluid.

(N) In the variable displacement vane pump according to claim 4,
The pump housing has a bottomed tubular first housing in which a tubular portion and a bottom portion that closes one axial side of the tubular portion are integrally formed, and closes the other side opening of the tubular portion. A second housing,
The variable capacity vane pump, wherein an outer end portion of the suction passage is formed to be opened in the cylindrical portion.

  By adopting such a configuration, it is possible to ensure a relatively large opening area of the suction passage as compared with the case where the second housing is formed, and it is possible to improve the suction efficiency.

(O) In the variable displacement vane pump according to claim 4,
The suction passage is configured to communicate with the suction region from both axial sides,
A variable displacement vane pump characterized in that a lubrication groove for sliding lubrication of the rotor is provided by guiding discharge pressure at a position facing one end wall of the pump element housing portion.

  By adopting such a configuration, it is possible to avoid a problem that the negative pressure on the suction region side affects the space around the drive shaft due to the discharge pressure guided to the lubrication groove.

(P) In the variable displacement vane pump according to claim 4,
The variable displacement vane pump, wherein the drive shaft side seal member and the low pressure chamber side seal member are formed separately from each other.

  By adopting such a configuration, there is an advantage that the shape of each seal member can be simplified as compared with a case where a part of both seal members are connected and configured integrally.

DESCRIPTION OF SYMBOLS 10 ... Pump element accommodating part 11 ... Pump housing 12 ... Drive shaft 14 ... Cam ring 21 ... Rotor 22 ... Vane 23 ... Pressure plate 25a ... 1st suction port (suction part)
25b ... Second suction port (suction part)
27a ... first low pressure chamber (low pressure chamber)
27b ... Second low pressure chamber (low pressure chamber)
30 ... Pump chamber 31a ... First discharge port (discharge portion)
31b ... 2nd discharge port (discharge part)
33 ... High pressure chamber 34 ... Drive shaft insertion hole 35a ... First shaft hole (bearing portion)
35b ... 2nd shaft hole (bearing part)
S1 ... 1st seal member (drive shaft side seal member)
S2 ... Second seal member (low pressure chamber side seal member)

Claims (4)

A pump housing having a pump element housing therein;
A drive shaft rotatably supported by the pump housing;
A rotor housed in the pump element housing portion and driven to rotate by the drive shaft;
A plurality of vanes provided so as to be able to appear and retract in a plurality of slots radially formed in the outer periphery of the rotor;
A cam ring which is swingably provided on the outer peripheral side of the rotor in the pump element accommodating portion, and forms a plurality of pump chambers together with the adjacent vanes and the rotor;
A suction portion that is formed on one end wall of the pump element housing portion and opens to a suction region in which the volume of each pump chamber increases with rotation of the rotor;
A suction passage provided in the pump housing and serving for suction of hydraulic fluid by connecting an oil pan for storing hydraulic fluid and the suction portion;
A pressure plate disposed adjacent to one end wall of the pump element housing portion, and having one axial end surface disposed so as to be slidably contactable with the rotor and the cam ring;
A discharge part provided in the pressure plate and opening to a discharge region in which the volume of each pump chamber decreases with rotation of the rotor;
A high-pressure chamber that is provided on one end wall of the pump element accommodating portion, and that biases the pressure plate toward the rotor side by guiding discharge pressure from the discharge portion;
A low-pressure chamber provided at a position corresponding to the suction region of the one end wall of the pump element housing portion, and to which suction pressure is guided;
A bearing portion drilled in one end wall of the pump element housing portion and bearing the drive shaft;
A drive shaft side seal member interposed between one end wall of the pump element accommodating portion and a pressure plate, and separating the bearing portion and the high pressure chamber;
A low-pressure chamber side seal member interposed between one end wall of the pump element accommodating portion and a pressure plate, and separating the low-pressure chamber, the high-pressure chamber and the bearing portion;
A variable displacement vane pump characterized by comprising:   2. The variable displacement vane pump according to claim 1, wherein the pump element housing portion and the outside of the pump housing are configured to communicate with each other via a radial clearance between the pump housing and the drive shaft. The pump housing has a bottomed tubular first housing in which a tubular portion and a bottom portion that closes one axial side of the tubular portion are integrally formed, and closes the other side opening of the tubular portion. A second housing,
2. The variable displacement vane pump according to claim 1, wherein an outer end portion of the suction passage is formed to open in the cylindrical portion. A pump housing having a pump element housing therein;
A drive shaft rotatably supported by the pump housing and driven to rotate by a vehicle engine;
A rotor housed in the pump element housing portion and driven to rotate by the drive shaft;
A plurality of vanes provided so as to be able to appear and retract in a plurality of slots radially formed in the outer periphery of the rotor;
A cam ring which is swingably provided on the outer peripheral side of the rotor in the pump element accommodating portion, and forms a plurality of pump chambers together with the adjacent vanes and the rotor;
A suction portion that is formed on one end wall of the pump element housing portion, opens to a suction region in which the volume of each pump chamber increases with rotation of the rotor, and is disposed vertically below the drive shaft;
A suction passage provided in the pump housing and serving for suction of hydraulic fluid by connecting an oil pan for storing hydraulic fluid and the suction portion;
A pressure plate disposed adjacent to one end wall of the pump element housing portion, and having one axial end surface disposed so as to be slidably contactable with the rotor and the cam ring;
A discharge unit provided in the pressure plate, opening to a discharge region in which the volume of each pump chamber decreases with rotation of the rotor, and disposed on a vertically upper side of the drive shaft;
A high-pressure chamber that is provided on one end wall of the pump element accommodating portion, and that biases the pressure plate toward the rotor side by guiding discharge pressure from the discharge portion;
A low-pressure chamber provided at a position corresponding to the suction region of the one end wall of the pump element housing portion, and to which suction pressure is guided;
A bearing portion drilled in one end wall of the pump element housing portion and bearing the drive shaft;
A drive shaft side seal member interposed between one end wall of the pump element accommodating portion and a pressure plate, and separating the bearing portion and the high pressure chamber;
A low-pressure chamber side seal member interposed between one end wall of the pump element accommodating portion and a pressure plate, and separating the low-pressure chamber, the high-pressure chamber and the bearing portion;
A variable displacement vane pump characterized by comprising:

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