JPH0614480U - Variable displacement vane pump - Google Patents

Abstract

(57) [Abstract] [Purpose] The deformation of the cam ring due to the stress concentration generated at the contact portion 34 due to the discharge pressure is prevented. [Structure] The cam ring 3 is formed with port grooves 32A and 32B in an inner peripheral portion near the discharge port 42 for preventing fluctuation of a discharge section due to rocking of the cam ring 3, and these port grooves 32A and 32B are supported. It is formed separately except for the contact portion 34 with the shaft 31. Thereby, the contact portion 3
The plate thickness of No. 4 is sufficiently secured, and even if the high pressure from the discharge port 42 acts, the contact portion 34 is not deformed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a variable displacement vane pump, particularly to increase the rigidity of a cam ring.

[0002]

[Prior art]

 An example of the pump portion of the variable displacement vane pump is shown in FIG. A circular ring-shaped rotor 1 is arranged in the center of the circular space of the pump housing 4, and its central opening is fixed to a rotation shaft (not shown) and rotates integrally with it (arrow in FIG. 3). A circular cam ring 3 is provided between the rotor 1 and the pump housing 4, and the cam ring 3 is a circular shaft member in which a semicircular recess formed on the outer periphery of one side is arranged between the inner ring and the housing 4. 31 and the other side portion abuts on the inner wall of the housing 4 via the seal member 35, and is vertically swingable about the shaft member 31 as a fulcrum.

A part of the other side portion of the cam ring 3 projects into a recess of the pump housing 4 to form a spring receiver 36, and a spring receiver 36 is provided between the spring receiver 36 and the lower surface of the recess. An il spring 37 is provided.

The rotor 1 is provided with a plurality of (nine in the figure) vanes 2 that are movable in the radial direction at equal intervals in the circumferential direction, and each vane 2 advances at its inner end portion by receiving pump discharge pressure. The front end of the cam ring 3 contacts the inner peripheral surface of the cam ring 3 to form a pump chamber P between the vane 2 and the adjacent vane 2. The pump chamber P is closed by walls of the housing 4 that abut on both side surfaces of the vanes 2 and the cam ring 3.

In the space 5 between the upper half of the cam ring 3 extending from the support shaft 31 to the seal member 35 and the inner wall of the pump housing 4, the pressure of the discharged fluid acts as a control pressure via a control valve (not shown). It is introduced from the control port 6 in the pump housing 4 and is controlled so that the discharge amount produces a pressure according to the usage condition of the load, while the space 7 between the lower half of the cam ring 3 and the wall of the pump housing 4 is controlled. The inside is the return pressure. However, when the control pressure increases due to an increase in the discharge amount from the pump due to an increase in the pump rotation speed, the cam ring 3 swings downward against the spring force of the coil spring 37 with the support shaft 31 as a fulcrum. As shown in the figure, the eccentricity between the center of the cam ring 3 and the center of the rotor 1 is small, the volume change of the pump chamber P formed between the vanes 2 due to the rotation is small, and the pump discharge amount is small.

When the pump rotation speed decreases, the pump discharge amount decreases, and the control pressure decreases, the cam ring 3 swings upward due to the spring force of the coil spring 37 and is formed between the cam ring 3 and the eccentric cam ring 3. In addition, each of the pump chambers P described above rotates while its volume changes. Then, the fluid is sucked from the suction port 41 formed in an arc shape at an inner position along the side portion of the cam ring 3 facing the pump chamber P of which the volume gradually increases, and the volume of the pump gradually shrinks. The fluid is pumped and discharged to a discharge port 42 facing the chamber P and formed in an arc shape at an inward position along the other side portion of the cam ring 3.

When the cam ring 3 swings, the relative position between the cam ring 3 and each port 41, 42 changes, and the suction section and the discharge section change. Therefore, in order to prevent this, the cam ring along each port 41, 42 Port grooves 32 and 33, both ends of which extend longer than both ends of the ports 41 and 42, are formed on the inner peripheral portions of the three side surfaces.

[0008]

[Problems to be solved by the device]

 By the way, in the conventional pump structure described above, the pressure in the pump chamber facing the discharge port 42 is high, and this high pressure acts on the cam ring 3, so that a force is applied to the cam ring 3 in the right direction in FIG. There is a possibility that the stress concentrates on the contact portion 34 and the cam ring 3 is deformed at this portion (two-dot chain line in FIG. 3) and its inner peripheral profile changes.

The present invention solves such a problem, and an object thereof is to provide a variable displacement vane pump capable of effectively preventing deformation of a cam ring.

[0010]

[Means for Solving the Problems]

 The structure of the present invention will be described. A plurality of vanes 2 which are urged outward in the radial direction are provided on the outer periphery of a rotor 1 at equal intervals, and one portion of the outer periphery of the rotor 1 is provided as a spindle. A cam ring 3 which is brought into contact with 31 so as to be swingable around the support shaft 31 is provided, and the tip of each vane 2 is brought into contact with the inner peripheral surface of the cam ring 3 and each vane 2 Further, housing 4 walls are brought into contact with both side surfaces of the cam ring 3 to form a closed pump chamber P between the vanes 2, and a fluid is sequentially transferred to each pump chamber P from an intake port 41 provided in the housing 4 wall. And the fluid is sequentially discharged from each pump chamber P to the discharge port 42 provided on the wall of the housing 4 described above, and a control pressure is applied to the outer surface of the cam ring 3 substantially half the circumference, and the cam ring 3 is responsive to the control pressure. From the eccentric position A variable-capacity vane pump configured to oscillate and move to a stationary position to adjust a discharge flow rate, and along a discharge port 42 that is opened in an inward direction of the cam ring 2 on a side that abuts a support shaft 31. Port grooves 32A and 32B extending in the circumferential direction are formed in the inner peripheral portion of the side surface of the cam ring 3, and the port grooves 32A and 32B are divided in the middle to remove the contact portion 34 of the cam ring 3 to the support shaft 31. The above-mentioned port grooves 32A and 32B are formed in the range.

[0011]

[Action]

 In the above structure, since the port groove 32A, 32B is not formed in the contact portion 34 of the cam ring 3 with respect to the support shaft 31, the plate thickness of the cam ring 3 becomes sufficiently thick at this portion, and the rigidity thereof is improved. Therefore, even if the high pressure from the discharge port 42 acts, the contact portion 34 is not deformed.

Further, the port grooves 32A and 32B formed excluding the contact portion 34 effectively prevent the variation of the discharge section during the swing of the cam ring 3.

[0013]

【Example】

 An embodiment of the present invention will be described below. The overall structure of the pump is the same as that of the conventional example already described, and the differences from the conventional example will be mainly described.

In FIG. 1, one side portion of the cam ring 3 is in contact with the support shaft 31 at a semicircular recess 341 formed in a rectangular protrusion on the outer circumference, and can swing vertically about the support shaft 31. Is. A discharge port 42 extending in the circumferential direction in an arc shape is formed at an inner position of the one side portion, and the discharge port 42 is formed on the side surface inner peripheral portion of the cam ring 3 along the discharge port 42. Port grooves 32A and 32B extending in the circumferential direction longer than the end grooves are formed along both ends.

Each of the port grooves 32A and 32B is formed by removing the side surface of the cam ring 3 at a constant depth. The port grooves 32A and 32B are, except for the contact portion 34 with respect to the support shaft 31, as shown in FIG. Are formed and are spaced apart from each other.

In such a structure, when the cam ring 3 swings around the support shaft 31, the relative position of the cam ring 3 and the discharge port 42 changes, but the respective port grooves 32A and 32B formed in the cam ring 3 are discharged. Since it communicates with the end of the port 42, fluctuations in the discharge area are prevented.

Since each of the port grooves 32 A and 32 B is not formed in the contact portion 34, the plate thickness of the cam ring 3 in this portion is sufficiently secured, and the contact portion is protected by the high pressure of the discharge port 42. Even if a large stress is concentrated on 34, no deformation occurs.

[0018]

[Effect of device]

 As described above, according to the variable displacement vane pump of the present invention, since the port groove is not formed in the contact portion with the support shaft, the plate thickness of the contact portion increases and the rigidity increases. Even if stress concentrates on this portion, the cam ring can be effectively prevented from being deformed. Further, since the discharge section is determined by the port groove excluding the contact portion, the fluctuation of the discharge section when the cam ring swings can be prevented as usual.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a pump unit according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of a pump unit.

FIG. 3 is a cross-sectional view of a pump section showing a conventional example.

[Explanation of symbols]

 1 rotor 2 vane 3 cam ring 31 support shaft 32A, 32B port groove 34 contact part 4 housing 41 suction port 42 discharge port P pump chamber

Claims (1)

[Scope of utility model registration request] 1. A plurality of vanes urged outward in the radial direction are provided on the outer periphery of a rotor at equal intervals, and one outer periphery of the rotor is brought into contact with a support shaft to support the support shaft. A cam ring that is swingable around is disposed so that the tip of each vane is brought into contact with the inner peripheral surface of the cam ring, and the housing walls are brought into contact with both side surfaces of each vane and the cam ring. A closed pump chamber is formed between the vanes, and the fluid is sequentially sucked from the suction port provided on the housing wall to each pump chamber, and the fluid is sequentially discharged from each pump chamber to the discharge port provided on the housing wall. , A variable displacement vane pump adapted to actuate a control pressure on the outer surface of substantially the half circumference of the cam ring and swing the cam ring from an eccentric position to a concentric position according to the control pressure to adjust the discharge flow rate. And a port groove extending in the circumferential direction on the inner peripheral surface of the side surface of the cam ring along the discharge port opening inwardly of the cam ring on the side abutting the support shaft, and the port groove is formed midway. A variable displacement vane pump characterized in that the port groove is formed in a range excluding a contact portion of the cam ring with respect to the support shaft.