JPH03275995A - Vane pump - Google Patents

Abstract

PURPOSE:To prevent an vane pushing ring from rattling so as to reduce the rotary resistance of a rotor by forming in the rotor a communicating passage for communicating each small room of a circular channel at the axial end face of the rotor and the inner peripheral side portion of the channel with each other, the small rooms being partitioned by a vane. CONSTITUTION:A circular channel 33 is formed at one axial end face of a rotor 3 and a guide ring 35 is loosely inserted into the channel 33 and a circular channel 34 is also formed at the other axial end face of the rotor 3. The channel 33 is divided into an outer peripheral side portion and an inner peripheral side portion 331 by insertion of the guide ring 35 and the outer peripheral side portion is further divided into a plurality of small rooms 332 by a vane 4. A plurality of through holes 37 are formed through a wall 36 located between the channels 33, 34 of the rotor 3 to communicate each small room 332 with the inner peripheral side portion 331. Each of the through holes 37 is so formed as protruding to walls on both sides of the channels 33, 34 and each small room 332 is communicated with the inner peripheral side portion 331 via the through holes 37. When the capacity of each small room is increased or decreased by rotation of the rotor fluids in each small room are circulated through the communicating passage so that pressure within each small room is held constant.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vane pump used, for example, as an oil supply pump for automatic transmissions of automobiles.

[Prior Art] Conventionally, as this type of vane pump, a variable displacement vane pump disclosed in, for example, Japanese Unexamined Patent Publication No. 55-17696 has been known.

This conventional pump includes a pump housing having a fluid suction passage and a fluid discharge passage, a cam ring (ring member) provided within the pump housing, and a rotor (rotor) provided within the cam ring and driven to rotate. A plurality of vanes are provided on the outer circumferential portion of the rotor so as to be movable in the radial direction, and the outer ends in the radial direction are in sliding contact with the inner circumferential surface of the cam ring.

The cam ring is swingably supported by the pump housing via a pivot pin so that its center can be eccentric with respect to the rotational axis of the rotor, and the amount of eccentricity is increased by the spring force of the cam spring. biased in the direction.

An annular groove is provided in the axial end face of the rotor, and the radially inner end of each vane faces into this groove. In addition, a vane extrusion ring is inserted into this groove in a 'fi-fitted state in contact with the radially inner end of each vane to push each vane toward the inner circumferential surface of the cam ring. The outer end is ensured to make sliding contact with the inner circumferential surface of the cam ring. Further, by inserting a vane extrusion ring into the groove, the groove is divided into an outer circumference side portion and an inner circumference side portion, and the outer circumference side portion is further divided into a plurality of small chambers by the vanes.

A plate-shaped seal member is provided between the cam ring outer circumferential surface and the pump housing inner circumferential surface at a position substantially opposite to the pivot pin, and this seal member and the pivot pin seal the cam ring outer circumferential surface and the pump housing inner circumference. A space between the surfaces is partitioned, and a control pressure chamber is formed in the partitioned space.

This control pressure chamber is configured so that a control pressure corresponding to the flow rate (discharge amount) of fluid in the fluid discharge passage is introduced from the fluid discharge passage through a control valve, and the cam ring is caused to shift by the amount of eccentricity depending on the control pressure. is configured to be biased in the direction of decreasing.

With the above configuration, this conventional pump rotates the rotor to suck fluid into the pump chamber formed between the inner circumferential surface of the cam ring and the outer circumferential surface of the rotor through the fluid suction path, thereby pumping the fluid. The fluid can be discharged from the chamber through the fluid discharge passage. Also,
This conventional pump can change the eccentricity of the cam ring according to the control pressure introduced into the control pressure chamber, and can change the discharge amount according to the eccentricity of the cam ring. .

[Problems to be Solved by the Invention] In the pump configured as described above, the volume of the small chamber formed in the outer circumferential portion of the vane extrusion ring of the groove increases or decreases as the rotor rotates. Therefore, when the small chamber is sealed, the fluid inside the small chamber is compressed and expanded, creating rotational resistance of the rotor.

Therefore, in the past, the height of the vane extrusion ring was made lower than the depth of the groove, and there was a gap between the bottom of the groove or the side surface of the housing bore (pump housing inner surface) and the axial end surface of the vane extrusion ring. A gap is provided, and the small chamber is communicated with the inner circumferential side of the groove through this gap, so that the fluid in the small chamber can be released to the inner circumferential side of the groove, or from the inner circumferential side to the small chamber. The pressure inside the chamber was kept constant by allowing fluid to be introduced.

However, since a gap is provided between the bottom surface of the groove or the inner surface of the pump housing and the axial end surface of the vane extrusion ring as described above, there is a problem in that the vane extrusion ring rattles.

In view of the above circumstances, it is an object of the present invention to provide a vane pump in which the rotational resistance of the rotor can be suppressed without rattling of the vane extrusion ring.

[Means to solve the problem]

The vane pump according to the present invention includes a pump housing having a fluid suction passage and a fluid discharge passage, a rotor provided in a substantially cylindrical lumen of the pump housing and driven to rotate, and a radial direction provided on the outer periphery of the rotor. A ring-shaped groove is formed in the axial end surface of the rotor, and each radially inner end of the plurality of vanes faces into this groove. , a vane extrusion ring that contacts the radially inner end of each vane and pushes each vane radially outward is inserted in a loosely fitted state, and the vane extrusion ring connects the groove to the outer circumferential side portion and the inner side portion. In the vane pump, the outer circumferential side of the groove is divided into a plurality of small chambers by the respective vanes, and each of the small chambers and the inner circumferential side of the groove are communicated with the rotor. A communication path is formed.

In the pump described above, it is preferable that the portion of the communication passage facing the small chamber be formed closer to the rear vane in the rotational direction of the rotor among the vanes located on both sides of the communication passage.

[Effect]

According to the above configuration, when the volume of the small chamber increases or decreases as the rotor rotates, the fluid in the small chamber escapes to the inner circumference side of the groove through the communication path, or the fluid in the inner circumference side increases or decreases. The pressure inside the chamber is kept constant by introducing it into the chamber through the communication path.

In particular, if the part of the communication passage facing the small chamber is formed closer to the vane on the rear side in the rotational direction of the rotor among the vanes located on both sides of the communication passage, the fluid in the small chamber can be smoothly communicated when the volume of the small chamber is reduced. The water passes through the passage and escapes to the inner circumferential side of the groove.

〔Example〕

1 to 3 show an embodiment of a vane pump according to the present invention.

This vane pump is called a variable displacement vane pump, and includes a pump housing 1, an annular cam ring 2, and a rotor 3.

The pump housing 1 consists of a passage-side housing 1a and a cover-side housing 1b, and a substantially cylindrical recess is formed in the center of the passage-side housing 1a, and the opening of this recess is closed by the cover-side housing 1b. It constitutes a housing inner cavity 1c. Further, a fluid suction passage 11 and a fluid discharge passage 12 are formed through the passage side housing 1a, and these fluid suction passage 11 and fluid discharge passage 12 are formed through the passage side housing 1a.
Each one end thereof is opened at the outer peripheral flange portion of the passage-side housing 1a to form an inlet port 11a and a discharge port 12a. On the other hand, the fluid suction path 11 and the fluid discharge path 12
The other ends of the pump chamber 6 and the second control pressure chamber 92 each open into a pump chamber 6 and a second control pressure chamber 92 during a volume increase process, which will be described later.

The cam ring 2 has a circular inner peripheral surface 21 and is provided within the housing inner cavity 1C. Each axial end surface of the cam ring 2 is in close contact with each side surface (pump housing inner surface) 13, 14 of the housing bore 1C, respectively.

The rotor 3 is formed to have a smaller diameter than the circular inner circumferential surface 21 of the cam ring 2, is provided within the circular inner circumferential surface 21 of the cam ring 2, and has both axial end surfaces facing the pump housing inner surface 21.
3.14 is closely followed.

Further, this rotor 3 is connected to a rotor drive shaft 3a inserted through the cover-side housing 1b, so that the rotor 3 rotates in the direction of arrow C in FIG. 1 about its axis α.

A plurality of vane grooves 31 are formed radially on the outer circumference of the rotor 3. Each vane groove 31 is connected to the rotor outer peripheral surface 32.
The vane 4 is fitted into each vane 11t31 so as to be movable in the radial direction of the rotor.

An annular 11t33 is formed on one axial end surface of the rotor 3, and a guide ring (vane extrusion ring) 35 is loosely inserted into this groove 33.

Further, an annular ring 34 is formed on the other end surface of the rotor 3 in the axial direction, thereby maintaining the balance of pressure received from the fluid between one end surface side and the other end surface side of the rotor 3, and causing the rotor 3 to oscillate in the axial direction. I try not to.

The radially inner end of each vane 4 faces inside each 21133.34, and each inner end touches the outer peripheral surface of the guide ring 35, and each vane 4 is pushed radially outward by the guide ring 35. There is. The height of the guide ring 35 is I!
33, thereby preventing a gap from being formed between one end surface of the guide ring 35 and the bottom surface of the groove 33 and between the other end surface of the guide ring 35 and the inner surface 14 of the pump housing. This is to prevent the guide ring 35 from wobbling in the axial direction.

The groove 33 is divided into an outer peripheral part and an inner peripheral part 331 by inserting the guide ring 35, and the outer peripheral part is further divided into a plurality of small chambers 332 by the vanes 4.

A plurality of through holes 37 are formed in the wall 36 between the grooves 33 and 34 of the rotor 3. Each through hole 37 extends in the radial direction from the inner circumferential side portion 331 of the groove 33 to each small chamber 332, and forms a communication path that communicates each of these small chambers 332 and the inner circumferential side portion 331. Further, this through hole 37 is formed by the groove 33.
The guide ring 35 is formed to protrude from the walls on both sides (inner and outer peripheral sides) of the through hole 37 .
When touching the side wall of 1133.34 at the position,
The small chamber 332 and the inner circumference side portion 331 are communicated with each other via the through hole 37.

The vane 4 includes a rotor 3 in addition to the guide link 35.
The rotor is also urged outward in the radial direction by the centrifugal force accompanying the rotation of the cam ring 2, so that the outer end in the radial direction
The circular inner circumferential surface 21 is welded by being constantly pressed against the circular inner circumferential surface 21.

Outer peripheral surface 22 of cam ring 2 and pump housing inner peripheral surface 1
5 are formed with semicircular recesses 23a and 18 that face each other. A cylindrical pivot roller 23 is provided between these recesses 23a, 18 with its outer peripheral surface in contact with the inner peripheral surface of each recess 23a, 18.
The cam ring 2 is supported by the pump housing 1 so as to be swingable about the center 02 of the pivot roller 23 in the directions of arrows A and B in FIG. This results in
The center of the cam ring 2 (the center of the circular inner circumferential surface 21 > 0
3 can be eccentric with respect to the rotational axis α of the rotor 3. Note that the distance from the swing center 02 of the cam ring 2 to the rotational axis α of the rotor 3 and the distance from the swing center 02 of the cam ring 2 to the rotation axis α of the rotor 3 are
is set to be equal to the distance to the center 03.

A spring seat 24 is formed on one side of the cam ring 2 bordering on a center line β passing through the center 03 and the swing center 02. A spring force of a cam spring 25 is applied to this spring seat 24, which urges the cam ring 2 in the direction of increasing eccentricity (in the direction of arrow B in FIG. 1), thereby pressing the cam ring 2 to the maximum eccentric position. ing. Note that the spring force of the cam spring 25 can be adjusted using an adjustment screw (not shown).

Further, a stopper portion 26 is protruded from the other side of the cam ring outer circumferential surface 22 bordering on the center line β, and this stopper portion 26 is located at the maximum eccentricity of the cam ring 2! I! In the state shown in Figs. 1 and 3, the cam ring 2 comes into contact with a part (stopper surface) 15a of the inner circumferential surface 15 of the pump housing, thereby stopping the movement of the cam ring 2 in the direction of increasing eccentricity. There is.

A portion (surface) 22a of the cam ring outer circumferential surface 22 on the side substantially opposite to the swing center 02 is formed into an arcuate surface centered on the swing center 02. A sealing member 5 is interposed between this surface 22a and the pump housing inner circumferential surface 15, and the space between the cam ring outer circumferential surface 22 and the pump housing inner circumferential surface 15 is defined by this sealing member 5 and the pivot roller 23. It is divided into two parts. A first control pressure chamber 91 is provided on one side (cam ring eccentric side) of the space divided into two, and a second control pressure chamber 92 is provided on the other side.

Fluid pressure is introduced into the first and second control pressure chambers 91 and 92, respectively, as will be described later, and the first control pressure chamber 91 uses the introduced fluid pressure to bias the cam ring 2 in the direction of decreasing the amount of eccentricity. The second control pressure chamber 92 is configured to bias the cam ring 2 in the direction of increasing the amount of eccentricity by the introduced fluid pressure.

As shown in FIG. 5, the sealing member 5 is formed into a generally crescent shape as a whole. Moreover, this seal member 5
The inner circumferential surface (the surface on the cam ring outer circumferential surface 22 side) 51 is formed into an arcuate surface along the circular arc portion 22a of the cam ring outer circumferential surface 22, and the outer circumferential surface (the surface on the pump housing inner circumferential surface 15 side) 52 The seal member 5 is formed into an arcuate surface along the circular inner circumferential surface 15 of the pump housing 1.Furthermore, both side surfaces of the seal member 5 are formed on the inner circumferential surface 13 of the pump housing.
It is closely followed by 14.

The pivot roller 23 is provided with both end surfaces in close contact with the inner surface 13, 14 of the pump housing, respectively. Therefore, the pivot roller 23 has a sealing action, and the pivot roller 23 and the seal member 5 reliably seal the space between the first control pressure chamber 91 and the second control pressure chamber 92. Alternatively, both ends of the pivot roller 23 may be embedded in the inner surface 13, 14 of the pump housing.

The inner peripheral surface 21 of the cam ring 2 and the outer peripheral surface 32 of the rotor 3
A space surrounded by the inner surface 13, 14 of the pump housing is divided into a plurality of parts by the vane 4, and a plurality of pump chambers 6 are formed in the space. The center 03 of the cam ring 2 is eccentric with respect to the rotational axis α of the rotor 3, so that the volume of each pump chamber 6 increases or decreases as the rotor 3 rotates.

The pump chamber 6 position in the latter half of the volume reduction process on the inner surface 13 of the pump housing is for discharge? 1195 is formed. As shown in FIG. 4, the part of the cam ring 2 closer to the second control pressure chamber 92 than the pivot roller 23 has a pump chamber 6 and a second control pressure chamber 6 facing the middle part of the discharge groove 95.
A first fluid pressure introduction path 7 communicating with the control pressure chamber 92 is formed through the first fluid pressure introduction path 7 . A constriction portion (orifice) 73 is provided in the opening portion of the first fluid pressure introduction path 7 on the side of the pump chamber 6 . Further, in the portion of the cam ring 2 closer to the first control pressure chamber 91 than the pivot roller 23,
A second fluid pressure introduction path 9 that communicates the pump chamber 6, which the front end of the discharge groove 95 faces, with the first control pressure chamber 91.
5b is formed.

Pump chamber 6 in the first half of the volume reduction process of the cam ring inner peripheral surface 21
A side groove 210 is formed at the position, and this side 1!21c prevents sudden pressure fluctuations due to a decrease in the volume of the pump chamber 6.

In the above configuration, when the rotor 3 is rotated in the direction of arrow C from the state shown in FIG. Rotate and move.

Each pump chamber 6 communicates with the fluid suction path 11 during the volume increase process, and is connected to the fluid suction path 11 from the suction port 11a.
through which fluid such as oil is sucked, and in the volume reduction process, it communicates with the second fluid pressure introduction path 95b and the first fluid pressure introduction path 7, and the sucked fluid is transferred to the second fluid pressure introduction path 95b and the first fluid pressure introduction path. Discharge toward road 7. The fluid discharged toward the second fluid pressure introduction path 95b is introduced into the first control pressure chamber 91 through the second fluid pressure introduction path 95b, and the fluid discharged toward the first fluid pressure introduction path 7 is introduced into the second control pressure chamber 92 through the first fluid pressure introduction path 7, and then into the fluid discharge path 12 and discharged from the discharge port 12a.

Since the first fluid pressure introducing path 7 is provided with the constricted part 73, a pressure difference is generated before and after the constricted part 73, and the constricted part 73
The second control pressure chamber 92 on the downstream side has a constriction part 73.
A fluid pressure P2 lower than the fluid pressure P1 on the upstream side is introduced. On the other hand, the high fluid pressure P1 on the upstream side of the throttle part 73 is
Since the upstream portion of the throttle portion 73 and the upstream portion of the second fluid pressure introduction path 95b are communicated via the discharge groove 95, the fluid pressure is introduced into the first control pressure chamber 91 via the second fluid pressure introduction path 95b. be done. As a result, in addition to the spring force F of the cam spring 25 acting on the cam ring 2 in the direction of increasing the amount of eccentricity, the high fluid pressure P1 acts on the cam ring 2 in the direction of decreasing the amount of eccentricity.
The low fluid pressure P2 comes to act in the direction of increasing the amount of eccentricity. That is, the differential pressure ΔP (=P1-P2) between the high fluid pressure P1 and the low fluid pressure P2 acts on the cam ring 2 against the spring force E of the cam spring 25.

When the rotational speed N of the rotor 3 is low, the discharge amount Q is small;
The differential pressure ΔP also becomes smaller. Therefore, in this case, the differential pressure Δ
P is greater than the force acting on cam ring 2, cam spring 2
5 prevails, and the cam ring 2 is held at the maximum eccentric position.As a result, when the rotation speed N of the rotor 3 is low, the discharge amount Q increases in proportion to the rotation speed N.

On the other hand, as the rotation speed N of the rotor 3 increases, the discharge amount Q increases and the differential pressure ΔP also increases. Here, for example, if the spring force of the cam spring 25 is set to be balanced with the force due to the differential pressure ΔP when the discharge IQ reaches the predetermined amount QO, the rotation speed N of the rotor 3 will increase. When the discharge amount Q reaches the predetermined amount Qo, the force due to the differential pressure ΔP overcomes the spring force F of the cam spring 25, and the cam ring 2 begins to swing in the direction of decreasing eccentricity. The amount of eccentricity decreases, the displacement volume decreases, and the discharge amount Q is maintained so as not to exceed a predetermined IQo.In other words, according to the configuration of this pump, the rotor rotation speed N-discharge as shown in FIG. IQ characteristics can be obtained.

In addition, in this pump configuration, the guide ring 3 of the groove 33
A through hole (communication path) 37 is formed in the rotor 3 to communicate each small chamber 332 formed on the outer circumferential side of the groove 33 with the inner circumferential side 331 of the guide ring 35 of the groove 33. Therefore, the following effects can be obtained.

That is, in this pump, when the rotor 3 rotates, the volume of each small chamber 332 increases or decreases. However, since a through hole 37 is formed that communicates each small chamber 332 with the inner peripheral side portion 331 of the groove 33, when the volume of the small chamber 332 decreases, the fluid in the small chamber 332 is transferred to the through hole 33.
7 and is released into the inner peripheral side portion 331 of the groove 33.

Further, when the volume of the small chamber 332 increases, the fluid in the inner peripheral side portion 331 of the inner circumferential portion 331 comes to be introduced into the small chamber 332 through the through hole 37. In other words, when the rotor 3 rotates, the fluid inside the small chamber 332, which is in the process of decreasing its volume, escapes through the through hole 37 and into the inner peripheral side portion 331 of the groove 33.
The released fluid flows from the inner peripheral portion 331 to the through hole 37.
It is introduced into the small chamber 332 through which the volume is increased. Therefore, the pressure within each small chamber 332 and the inner circumferential portion 331 of the groove 33 is always kept constant, pressure fluctuations within the small chambers 332, etc. are prevented, and rotational resistance of the rotor 3 is suppressed.

In particular, as shown by the two-dot chain line in FIG.
2 is gradually narrowed from the front side in the rotational direction of the rotor 3 during the volume reduction process, so when the volume of the small chamber 332 decreases, the fluid in the small chamber 332 smoothly passes through the through hole 37 and flows into the groove 33. The rotational resistance of the rotor 3 can be further reduced. Note that the through hole 37 is formed at least in the small chamber 332.
It is sufficient that the portion facing the vane is located on the rear side of the vane in the rotational direction of the rotor 3.

Furthermore, in the configuration of the pump of the above embodiment, the portion 2 of the cam ring outer circumferential surface 22 on the side substantially opposite to the cam ring swing center 02
2a is formed into an arcuate surface centered on the cam ring swing center 02, and a seal member 5 is provided between this surface 22a and the pump housing inner circumferential surface 15, and this seal member 5 is formed into a substantially crescent shape as a whole. ing. Then, the inner peripheral surface 51 of the seal member 5 is connected to the arc-shaped portion 2 of the cam ring outer peripheral surface 22.
The outer circumferential surface 5 of the sealing member 5 is formed into an arcuate surface along 2a.
2 is formed into an arcuate surface along the circular inner circumferential surface 15 of the pump housing 1. Therefore, in addition to the seal member 5 and the cam ring outer peripheral surface 22, the seal member 5 and the pump housing inner peripheral surface 15, the seal member 5 and the pump housing inner surface 13
．． 14 come into contact with each other over a long distance, and the sealing member 5 can reliably seal between the first control pressure chamber 91 and the second control pressure chamber 92.

In addition, in order to configure a communication path, the through hole 3 of the above embodiment is
7, the rotor 3 may be provided with a groove 38 extending from the inner peripheral portion 331 to each small chamber 332, as shown in FIG. Furthermore, the present invention is not limited to variable displacement vane pumps, but can also be applied to fixed displacement vane pumps.

〔Effect of the invention〕

In the vane pump according to the present invention, a communication passage is formed in the rotor to communicate each small chamber with the inner peripheral side portion of the groove. For this reason, when the volume of the small chamber increases or decreases as the rotor rotates, the fluid in the small chamber may escape through the communication path to the inner circumferential side of the groove, or the fluid in the inner circumferential side may flow through the communication path. The pressure inside the chamber is kept constant by introducing the gas into the chamber. Therefore, pressure fluctuations in the small chamber etc. can be prevented, and rotational resistance of the rotor can be suppressed.

Moreover, since the rotational resistance of the rotor can be suppressed as described above, there is a gap between one axial end surface of the vane extrusion ring and the bottom surface of the groove, and between the other axial end surface of the vane extrusion ring and the inner surface of the pump housing. It is possible to fill the spaces between the vane extrusion rings without any gaps, and it is possible to prevent the vane extrusion ring from wobbling in the axial direction.

In particular, if the part of the communication passage facing the small chamber is formed closer to the vane on the rear side in the rotational direction of the rotor among the vanes located on both sides of the communication passage, the fluid in the small chamber can be smoothly communicated when the volume of the small chamber is reduced. The heat is allowed to escape through the passage to the inner peripheral side of the groove, thereby further suppressing the rotational resistance of the rotor.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the vane pump according to the present invention with the cover side housing removed, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a partially enlarged view of Fig. 1. , FIG. 4 is a sectional view taken along the line IN-■ in FIG. 1, FIG. 5 is a perspective view showing the seal member, FIG. FIG. 7 is a cross-sectional view showing the main parts of another embodiment. DESCRIPTION OF SYMBOLS 1... Pump housing, IC... Inner cavity of pump housing, 3... Rotor, 4... Vane, 11...
・Fluid suction path, 12... Fluid discharge path, 33... Annular groove, 35... Guide ring (vane extrusion ring)
, 37° 38... Communication path, 331... Inner peripheral side portion of groove, 332... Small chamber, C... Rotor rotation direction.

Claims (1)

[Claims] 1. A pump housing having a fluid suction passage and a fluid discharge passage; a rotor provided in a substantially cylindrical lumen of the pump housing and driven to rotate; a plurality of vanes provided so as to be movable in a direction, and an annular groove is formed in an axial end surface of the rotor;
Inside this groove, each radially inner end of the plurality of vanes faces, and a vane extrusion ring that contacts the radially inner end of each vane and pushes each vane radially outward. The vane extrusion ring is inserted in a loosely fitted state, and the groove is divided into an outer peripheral part and an inner peripheral part by the vane extrusion ring, and the outer peripheral part of the groove is divided into a plurality of small chambers by each vane. In vane pumps,
A vane pump characterized in that a communication passage is formed in the rotor to communicate each of the small chambers with an inner peripheral side portion of the groove. 2. The vane pump according to claim 1, wherein the portion of the communication passage facing the small chamber is formed closer to the rear vane in the rotational direction of the rotor among the vanes located on both sides of the communication passage.