JP6228867B2 - Variable displacement vane pump - Google Patents

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.

  This variable displacement vane pump has a pair of control chambers (first and second fluid pressure chambers) separated by a pin member and a seal member that are arranged in a radially opposed manner on the outer peripheral side of the cam ring. The discharge flow rate is made variable by controlling the hydraulic pressure and changing the volume change amount of each pump chamber based on the eccentric amount of the cam ring.

  The seal member includes a prismatic seal body housed in a seal groove formed in the inner peripheral surface of the adapter ring, and an urging member that urges the seal body from the bottom side of the seal groove toward the cam ring side. The seal body presses against the outer peripheral surface of the cam ring on the basis of the urging force of the urging member, thereby sealing the space between the two control chambers.

JP 2012-87777 A

  However, in the conventional variable displacement vane pump, since the seal main body is formed in a prismatic shape, the hydraulic pressure of each control chamber acts from the side as the cam ring swings, so that the seal main body is There is a possibility that the seal body is pressed by the opening end (corner) of the seal groove, and the seal body is caught in the radial gap between the cam ring and the adapter ring, and the seal body may be damaged by repeating such a phenomenon. It was.

  The present invention has been devised by paying attention to such a technical problem, and provides a variable displacement vane pump capable of suppressing damage to a seal member.

  In particular, the present invention is accommodated in a seal groove that is open toward the outer peripheral surface of the cam ring in the form of a pair of opposed inner walls formed on the peripheral wall of the pump element receiving portion, and the pair of inner walls of the seal groove A pair of side walls that come into contact with the inner walls by being urged against each other, and a cam contact portion that is provided between the side walls and comes into contact with the outer peripheral surface of the cam ring based on the urging force. And a sealing member.

  According to the present invention, since both side walls of the seal member are configured to protrude from the inner walls of the seal groove, the seal member is prevented from rattling in the seal groove, so that the seal member is open at the end of the seal groove. It is possible to suppress damage to the seal member due to interference.

1 is a longitudinal sectional 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 an enlarged view of a main part of FIG. 2. It is the figure showing the seal groove single-piece | unit shown in FIG. 4A and 4B are views showing a single seal member shown in FIG. 3, in which (a) is a perspective view and (b) is a front view. FIG. 4 is a view corresponding to FIG. 3 for explaining the function of the seal member. FIG. 4 is a view corresponding to FIG. 3 showing a second embodiment of the present invention. FIG. 4 is a view corresponding to FIG. 3 showing a conventional seal structure.

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 and 2. 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 disposed 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 40 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. Bolts are fastened through the formed fastening portions 15a and 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. On the inner peripheral surface of the adapter ring 13, a seal member 19 is accommodated and disposed in a seal groove 18 that is notched at a position substantially opposite to the pin member 17 in the radial direction. The pin member 17 and the seal member 19 are in pressure contact with the outer peripheral surface of the cam ring 14, respectively, so that the first fluid pressure chamber used for swing control of the cam ring 14 is provided between the adapter ring 13 and the cam ring 14 in the radial direction. H1 and the second fluid pressure chamber H2 are separated.

  The cam ring 14 is made of a sintered material of iron-based metal, 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 H 1 side is formed. Alternatively, the cam ring 6 is moved toward the first fluid pressure chamber H1, based on the biasing force of the coil spring 20 that is swingably supported on the second fluid pressure chamber H2 side and disposed on the second fluid pressure chamber H2 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”) is maximized.

  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.

  In addition, on one side surface of the pressure plate 23 that is a surface facing the rotor 21 and the inner side surface of the pump cover 16, regions in which the internal volumes of the pump chambers 30 gradually increase with the rotation of the rotor 21 (hereinafter referred to as the following). , Referred to as “suction region”), a pair of first suction port 25a and second suction port 25b that are notched in a substantially arcuate groove shape are provided along the circumferential direction. 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.

  Further, the one side surface of the pressure plate 23 and the inner surface of the pump cover 16 are substantially axially positioned relative to the first and second suction ports 25a and 25b, and the pumps are rotated as the rotor 21 rotates. The first discharge in the shape of a substantially arc groove formed in the same manner as the first and second suction ports 25a and 25b in a region where the internal volume of the chamber 30 gradually decreases (hereinafter referred to as "discharge region"). A port 31a and a 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.

  A discharge hole 32 is formed in the axial clearance Cx (excluding the first suction port 25a separated by the well-known O-ring 34) between the pressure plate 23 and the end wall 10b of the pump element housing 10. The hydraulic fluid discharged from the pressure chamber 33 toward the high pressure chamber 33 is acted on, and during the driving of the pump, the pressure plate 23 is moved to the adapter ring 13 by the discharge pressure P0 introduced into the axial gap Cx. It is urged to the side and is pressed against the cam ring 14 and the rotor 21.

  Here, in the pressure plate 23, a high pressure introduction passage 35 for introducing the discharge pressure P 0 into the seal groove 18 is provided along the axial direction at a position facing the bottom side of the seal groove 18 of the adapter ring 13. The hydraulic fluid that is formed through and flows into the axial gap Cx from the discharge hole 32 as described above is guided into the seal groove 18 through the high-pressure introduction passage 35, so that the seal member 19 will be described later. Thus, the urging force is applied (see FIG. 6).

  Further, on one side surface of the pressure plate 23 and the inner side surface of the pump cover 16, a first back pressure port 38a having an arc groove shape and a first back pressure port 38a are provided in a predetermined range in the circumferential direction facing each back pressure chamber 24 in the discharge region. Two back pressure ports 38b are cut out. The discharge pressure P0 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 P0 is guided to the second back pressure port 38b through the back pressure chamber 24. It has come to be.

  The control valve 40 closes a spool valve body 42 slidably received in a valve hole 41 formed in the pump body 15 and one end side (the right side in FIG. 2) of the valve hole 41. A valve spring 44 that is interposed between the plug 43 and the spool valve body 42 and urges the spool valve body 42 in the left direction in FIG. 2, closes the other end of the valve hole 41, and is not shown. The push rod is mainly composed of a solenoid 45 disposed so as to be linked with the spool valve body 42.

  In the control valve 40, 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 45 side separated by the first land portion 42a of the spool valve body 42. Configuration in which P0 is guided and hydraulic pressure P2 downstream of the metering orifice (not shown) is guided to the second control chamber R2 on the plug 43 side separated by the second land portion 42b of the spool valve body 42. Thus, the axial position of the spool valve body 42 is controlled by the differential pressure across the metering orifice and the urging force of the valve spring 44, thereby providing an eccentric amount control of the cam ring 14. The low-pressure chamber R0 defined between the land portions 42a and 42b 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 42 is located on the solenoid 45 side, the first fluid pressure is passed through the first communication passage 46a. The chamber H1 and the low pressure chamber R0 communicate with each other, and the second control chamber R2 and the second fluid pressure chamber H2 communicate with each other through the second communication passage 46b. As a result, the cam ring 14 has a fluid pressure in the second fluid pressure chamber H2. And the biasing force of the coil spring 20 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 42 moves toward the plug 43 against the urging force of the valve spring 44, the first control passage R1 passes through the first communication passage 46a. As a result, the first control chamber R1 and the first fluid pressure chamber H1 communicate with each other, and the low pressure chamber R0 and the second fluid pressure chamber H2 communicate with each other through the second communication passage 56b. Based on the pressure in the chamber H1, the swing control is performed so that the eccentric amount decreases against the urging force of the coil spring 20, and the pump discharge flow rate decreases.

  1 to 3, the seal member 19 is formed by bending a thin metal plate, and a pair of first and second inner walls 18a and 18b facing each other in the seal groove 18 are formed. A pair of first and second side walls 51 and 52 that are in contact with each other, and both side walls 51 and 52 are in contact with the outer peripheral surface of the cam ring 14, and the first and second fluid pressure chambers H1 and H2 are in contact with each other. And a cam contact portion 53 used for separation.

  The first and second side walls 51 and 52 are configured to be substantially parallel to the first and second inner walls 18a and 18b on the base end side, and are in contact with the inner walls 18a and 18b. The contact portions 51a and 52a and the first and second taper portions 51b and 52b each having a tapered shape that is gradually separated from the first and second inner walls 18a and 18b on the distal end side.

  Here, the first and second side walls 51 and 52, as shown in FIGS. 4 and 5, in particular, have a radial dimension L1 that is greater than a distance L2 between the bottom wall 18c of the seal groove 18 and the outer peripheral surface of the cam ring 14. Is set to be small, and is configured to be movable back and forth based on the discharge pressure P0 introduced through the high pressure introduction passage 35.

At this time, as shown in FIG. 3, the discharge pressure introduced inside the seal member 19 is P0, the fluid pressure in the first fluid pressure chamber is P1, and the fluid pressure in the second fluid pressure chamber is P2. The pressure receiving area of the force that the discharge pressure P0 urges the seal member 19 toward the cam ring 14 is S0, and the pressure receiving area of the force that the hydraulic pressure P1 of the first fluid pressure chamber H1 urges the seal member 19 toward the cam ring side is shown. S1, when the pressure receiving area of the force by which the hydraulic pressure P2 of the second fluid pressure chamber H2 urges the seal member 19 to the anti-cam ring side is S3,
Formula: P0 × S0> P1 × S1 + P2 × S2
The seal member 19 is not pushed back by the hydraulic pressures P1 and P2 of the first and second fluid pressure chambers, and good sealing performance can be ensured.

  Further, the first and second contact portions 51a and 52a are set to have a width dimension W1 equal to or slightly smaller than the groove width W2 of the seal groove 18, and have a discharge pressure P0 acting on the inside. By being spread outward, the first and second inner walls 18a and 18b are brought into contact with each other. That is, the first and second contact portions 51a and 52a are configured to maintain a state in which they are always in contact with the first and second inner walls 18a and 18b when the discharge pressure P0 is applied. On the other hand, the first and second taper portions 51b and 52b are always separated from the first and second inner walls 18a and 18b regardless of the advancement and retreat state of the seal member 19, and the separation amount is increased toward the tip side. It is configured.

  The cam contact portion 53 is formed in a curved surface which is convex toward the cam ring 14 side, and comes into contact with the outer peripheral surface of the cam ring 14 in a state where the seal member 19 has advanced based on the discharge pressure P0. It has become. In the present embodiment, the cam contact portion 53 is formed in a curved shape. However, the present invention is not limited to such a form. For example, the cam contact portion 53 may be formed in a flat shape. In this case, there is an advantage that a better sealing performance can be secured by increasing the sealing area.

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

  That is, in the pump according to this embodiment, when the pump is driven, the pump is introduced from the other side of the pressure plate 23 into the seal member 19 through the high pressure introduction passage 35 as indicated by an arrow in the drawing. When the seal member 19 is pushed away based on the discharge pressure P0, the first and second contact portions 51a and 52a abut against the inner walls 18a and 18b of the seal groove 18, respectively. The member 19 moves forward toward the cam ring 14 and the cam contact portion 53 comes into contact with the outer peripheral surface of the cam ring 14. When the discharge pressure P0 guided to the inside of the seal member 19 is not sufficient, such as immediately after the engine is started, the seal member 19 is in the retracted state as indicated by the alternate long and short dash line in FIG. In a low pressure state, there is no particular problem even if the sealing effect by the sealing member 19 is not sufficient.

  Here, as shown in FIG. 8, in the conventional structure in which the seal body S1 is pressed against the outer peripheral surface of the cam ring 14 based on the urging force of the rubber backup member S2, for example, between the seal groove 18 and the seal body S1. A width direction gap Cr is formed in the seal body S1 so that the seal body S1 can move in the width direction by the gap Cr, and the width dimension W1 of the seal body S1 is formed to be constant. The seal body S1 is pressed against the corner 18d at the opening end of the seal groove 18 by the hydraulic pressures P1 and P2 of the first and second fluid pressure chambers H1 and H2, and between the adapter ring 13 and the cam ring 14 By being sandwiched (see the alternate long and short dash line in the figure) and repeating such a phenomenon, the seal main body S1 is damaged.

  On the other hand, in the pump, as described above, the first and second contact portions 51a and 52a are urged (outward) by the hydraulic pressure (discharge pressure P0) introduced inside the seal member 19. Since it is configured to abut against the inner walls 18a and 18b of the seal groove 18), the abutment portions 51a and 52a are always stretched against the inner walls 18a and 18b when the pump is driven. Thus, the backlash of the seal member 19 due to the width-direction gap Cr as in the conventional case is suppressed.

  As a result, even if the hydraulic pressures P1 and P2 of the first and second fluid pressure chambers H1 and H2 act on the seal member 19, the seal member 19 is applied by the hydraulic pressures P1 and P2 of the fluid pressure chambers H1 and H2. Can be prevented from being pressed against the opening end (corner portion 18d) of the seal groove 18, and damage to the seal member 19 caused by such pressing can be suppressed.

  Further, each side wall 51, 52 of the seal member 19 is configured to be separated from the opening end (corner portion 18d) of the seal groove 18 by the first and second taper portions 51b, 52b. Even if the seal member 19 is slightly pressed in the width direction by the hydraulic pressures P1 and P2 of the second fluid pressure chambers H1 and H2, interference with the corner 18d of the seal groove 18 of the seal member 19 can be avoided. It is possible to effectively suppress damage to the seal member 19.

  In particular, the first and second taper portions 51b and 52b are configured so as to be separated from the corner portion 18d of the seal groove 18 even when the seal member 19 is in the most advanced state. Interference with the corner 18d of the seal groove 18 can be more effectively suppressed.

  The seal member 19 is configured to be able to advance and retreat with respect to the cam ring 14, and is configured to be separated from the bottom wall 18 c of the seal groove 18 when in contact with the cam ring 14. The member 19 can be made to follow the swinging (position change) of the cam ring 14, so that the sealing member 19 can ensure good sealing performance.

  Further, in the case of the present embodiment, since the discharge pressure P0 itself that is the maximum hydraulic pressure is adopted as the hydraulic pressure introduced into the inside of the sealing member 19, the sealing effect of the sealing member 19 and the above-described rattling suppression are suppressed. It is possible to exert the effect most effectively.

  In addition, at this time, since the discharge pressure P0 acting as the back pressure of the pressure plate 23 is guided to the seal groove 18 through the high pressure introduction passage 35 penetratingly formed in the pressure plate 23, it is simple. The discharge pressure P0 can be introduced with a typical structure.

Further, the cam contact portion 53 is also formed in a curved surface that is convex on the cam ring 14 side, so that the cam ring 14 is restrained from being caught when the cam ring 14 swings, and the cam ring 14 swings. Accordingly, there is an advantage that the relative angle change between the outer peripheral surface of the cam ring 14 and the cam contact portion 53 can be absorbed.
[Second Embodiment]
FIG. 7 shows a second embodiment of the variable displacement vane pump according to the present invention. The difference from the first embodiment is that the biasing means of the seal member 19 is not hydraulic pressure, It is constituted by the elastic force of the seal member 19 itself.

  That is, the seal member 19 according to the present embodiment is set so that the width direction dimension W1 of the seal member 19 is larger than the groove width W2 of the seal groove 18, and in the present embodiment, the side walls 51, As a result of being elastically deformed so as to constrict 52 and being inserted into the seal groove 18, a restoring force based on such elastic deformation as shown by an arrow in the figure is configured as an urging force. .

  According to this embodiment, when the biasing force is applied to the seal member 19, the discharge pressure P0 is not adopted, and the elastic force of the seal member 19 itself is adopted. Even in the state, there is an advantage that the play of the sealing member 19 as described above can be satisfactorily suppressed.

  The present invention is not limited to the configuration of each of the above embodiments, and the specific shape of the seal member 19 and the introduction path of the hydraulic pressure with respect to the seal groove 18 do not depart from the spirit of the present invention. It can be changed freely according to the specifications of the pump.

  In the first embodiment, the discharge pressure P0 itself is employed as the fluid pressure introduced into the seal member 19, but the present invention is not limited to this. That is, even when the discharge pressure P0 is derived, the discharge pressure P0 may be increased or decreased, and a fluid pressure other than the discharge pressure P0, for example, a fluid pressure in the second fluid pressure chamber H2 is introduced. It is also possible to do.

  In particular, when the hydraulic pressure P2 of the second fluid pressure chamber H2 is adopted as the introduction pressure, the friction during the swinging (sliding) of the cam ring 14 is reduced as compared with the case where the discharge pressure P0 itself is introduced. be able to. In addition, since a relatively high fluid pressure such as the downstream pressure of the metering orifice always acts on the second fluid pressure chamber H2, compared with the case where the fluid pressure P1 of the first fluid pressure chamber H1 that can be the suction pressure is employed. Thus, there is an advantage that a desired urging force can be constantly applied.

  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,
The hydraulic pressure of the hydraulic fluid introduced into the seal member is P0, the hydraulic pressure of the first fluid pressure chamber is P1, the hydraulic pressure of the second fluid pressure chamber is P2, and the hydraulic pressure P0 is The pressure receiving area of the force urging the seal member toward the cam ring side is S0, the pressure P1 is the pressure receiving area of the force urging the seal member against the cam ring side, and the hydraulic pressure P2 counteracts the seal member. When the pressure receiving area of the force urging the cam ring is S3,
The hydraulic pressure P0 is
Formula: P0 × S0> P1 × S1 + P2 × S2
A variable displacement vane pump characterized by satisfying pressure.

  By adopting such a configuration, it is possible to ensure good sealing performance without the seal member being pushed back by the hydraulic pressures of the first and second fluid pressure chambers.

(B) In the variable displacement vane pump according to (a),
The variable displacement vane pump characterized in that the hydraulic pressure of the hydraulic fluid introduced inside the seal member is the same as the hydraulic pressure of the discharge section.

  Thus, by introducing the highest hydraulic pressure inside the seal member, it is possible to most effectively exert the sealing effect and the rattling suppression effect of the seal member.

(C) In the variable displacement vane pump according to claim 2,
The variable displacement vane pump characterized in that the hydraulic pressure of the hydraulic fluid introduced into the seal member is the same as the hydraulic pressure of the second fluid pressure chamber.

  By adopting such a configuration, there is an advantage that the friction during the swinging of the cam ring can be reduced as compared with the case where the discharge pressure itself is introduced. In addition, since a relatively high hydraulic pressure always acts on the second fluid pressure chamber, it is possible to always apply a desired urging force as compared with the hydraulic pressure of the first fluid pressure chamber that can be a suction pressure. It becomes.

(D) In the variable displacement vane pump according to claim 1,
The variable displacement vane pump, wherein the seal member is housed in a compressed state in the seal groove.

  By adopting such a configuration, there is an advantage that it is possible to satisfactorily suppress the backlash of the seal member immediately after starting at a low hydraulic pressure.

(E) In the variable displacement vane pump according to claim 3,
The variable displacement vane pump, wherein the seal member is configured such that each side wall is separated from an opening end of the seal groove even when the seal member protrudes most from the seal groove.

  With this configuration, the seal member is always separated from the seal groove opening end, and interference with the seal groove opening end of the seal member can be effectively avoided.

(F) The variable displacement vane pump according to claim 1,
2. The variable displacement vane pump according to claim 1, wherein the cam contact surface is formed in a curved surface that is convex toward the cam ring side.

  By adopting such a configuration, it is possible to suppress the catch when the cam ring swings (slides), and to absorb the relative angle change between the outer peripheral surface of the cam ring and the cam contact surface due to the swing of the cam ring. is there.

(G) In the variable displacement vane pump according to claim 1,
The variable displacement vane pump, wherein the seal member is configured to be separated from a bottom surface of the seal groove in a contact state with the cam ring.

  With such a configuration, the seal member can be made to follow the swing (position change) of the cam ring, and a good sealing performance can be ensured by the seal member.

DESCRIPTION OF SYMBOLS 10 ... Pump element accommodating part 11 ... Pump housing 12 ... Drive shaft 14 ... Cam ring 18 ... Seal groove 18a ... 1st inner wall (a pair of inner walls)
18b ... 2nd inner wall (a pair of inner walls)
19 ... Sealing member 21 ... Rotor 22 ... Vane 25a ... First suction port (suction part)
25b ... Second suction port (suction part)
30 ... Pump chamber 31a ... First discharge port (discharge portion)
31b ... Second discharge port (discharge section)
40 ... Control valve 51 ... First side wall (a pair of side walls)
52 ... Second side wall (a pair of side walls)
53 ... Cam contact part H1 ... first fluid pressure chamber H2 ... second fluid pressure chamber

Claims (3)

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 an 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 discharge part that is formed in an end wall of the pump element housing part and opens to a discharge region in which the volume of each pump chamber decreases with rotation of the rotor;
A seal groove opened toward the outer peripheral surface of the cam ring in the form of forming a pair of opposed inner walls on the peripheral wall of the pump element accommodating portion;
The cam ring is provided between the pair of side walls which are accommodated in the seal groove and are urged against the inner walls of the seal groove to be in contact with the inner walls, and between the both side walls. A seal member having a cam contact portion that contacts the outer peripheral surface of
A first fluid pressure chamber provided on the side where the eccentric amount of the cam ring is increased, and provided on the side where the eccentric amount of the cam ring is decreased, is formed between the peripheral wall of the pump element housing portion and the outer peripheral surface of the cam ring. A second fluid pressure chamber,
A control valve for controlling the hydraulic pressure in the first fluid pressure chamber and the second fluid pressure chamber;
On one end side of the pump element accommodating portion, one end surface is provided to face the rotor and the cam ring, and the other end surface is opposed to the end wall of the pump element accommodating portion. A pressure plate that is biased toward the cam ring by introducing a discharge pressure,
The pressure plate has an opening formed in the seal groove at one end side and an opening formed in the other end surface side at the other end side, so that a high-pressure introduction groove for introducing the discharge pressure into the seal groove penetrates the pressure plate. A variable displacement vane pump characterized by being formed .   The variable displacement vane pump according to claim 1, wherein a discharge pressure of the discharge portion is introduced inside the seal member.   2. The variable displacement vane pump according to claim 1, wherein each side wall of the seal member is configured to be separated from an opening end of the seal groove in a circumferential direction of the pump element housing portion.

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