JPH08121354A - Vane pump - Google Patents

Abstract

PURPOSE: To improve sealing ability through stabilization of the press force of a vane, to improve the suction discharge efficiency of a pump through prevention of deviated wear of a vane, and to reduce the number of part items and facilitate installation. CONSTITUTION: A rotor 25 rotated in such a state to be pivotally supported on an eccentric shaft 26 is disposed in a cylinder hole formed in a cylinder body and a vane 28 is arranged in a vane groove 33, formed in the peripheral wall of a cylinder hole, in such a manner to protrude from and retract in the cylinder hole. The tip of the vane 28 is brought into slide contact with the outer periphery of the rotor 25 and a suction chamber 34 and a delivery chamber 35 are partitioned between the peripheral wall of the cylinder hole and the rotor 25. The back side of the vane of the vane groove 33 and a delivery chamber 35 are intercommunicated and the tip of the vane 28 is brought into slide contact with the outer periphery of the rotor 25 through the pressure of fluid discharged through rotation of the rotor 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vane pump,
More specifically, the present invention relates to a vane pump suitable as a negative pressure source for a negative pressure booster in a braking device of an electric vehicle or the like.

[0002]

2. Description of the Related Art In a vane pump, for example, FIGS.
As shown in FIG. 2, in the cylinder hole 2 formed in the cylinder body 1, the rotor 5 which is supported by the eccentric shaft 3 and rotates in the cylinder hole 2 by the drive of the motor 4 is arranged. A vane 7 is provided in a vane groove 6 formed in the peripheral wall so that the vane 7 can retract into and out of the cylinder hole 2.
Is pressed from the backside by springs 8 and 8 and the tip of the vane 7 is slidably contacted with the outer circumference of the rotor 5, and the suction chamber 9 and the discharge chamber 1 are provided between the peripheral wall of the cylinder hole 2 and the rotor 5.
There is one that divides 0 and.

[0003]

However, when the vane pump having the above-mentioned structure is used as a negative pressure source of a negative pressure booster in a braking device of an electric vehicle or the like, the spring pressing the vane also vibrates due to the vibration of the vehicle. As a result, the pressing force may change, the sealing performance between the tip of the vane and the outer periphery of the rotor may be impaired, and the pumping efficiency of the pump may decrease. In addition, the pressing force of the spring changes as the pressing force changes as the spring expands and contracts when the vane fully advances into the cylinder hole with the rotation of the rotor and when the vane retracts into the peripheral wall of the cylinder hole. May deteriorate, the suction and exhaust efficiency of the pump may decrease, and uneven wear may occur in the vanes. Further, the work of assembling the spring was also troublesome.

Therefore, according to the present invention, the pressing force of the vane is stabilized to improve the sealing property, the uneven wear of the vane is prevented to improve the suction and discharge efficiency of the pump, and the number of parts is reduced and the assembly is facilitated. It is intended to provide a vane pump.

[0005]

In order to achieve the above-mentioned object, according to the present invention, in a first aspect of the present invention, a rotor which is supported by an eccentric shaft and rotates is provided in a cylinder hole formed in a cylinder body. At the same time, the vane is provided in the vane groove formed on the peripheral wall of the cylinder hole so that the vane can be retracted into the cylinder hole,
In a vane pump in which a tip of the vane is brought into sliding contact with the outer circumference of the rotor to partition an intake chamber and a discharge chamber between the circumferential wall of the cylinder hole and the rotor, the vane back side of the vane groove and the discharge chamber are communicated with each other. The tip of the vane is brought into sliding contact with the outer circumference of the rotor by the pressure of the fluid discharged by the rotation of the rotor.
In the invention described above, a flow rate control valve is provided in the discharge passage continuing from the discharge chamber.

[0006]

[Operation] According to the above configuration, the vane is pressed from the rear surface by the discharge pressure of the fluid discharged from the discharge chamber as the rotor rotates, advances into the cylinder hole, and the tip slides on the outer circumference of the rotor. The fluid on the back surface of the vane is discharged from the discharge port as the vane sinks into the peripheral wall of the cylinder hole as the rotor rotates.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings.

FIGS. 1 to 3 show a first embodiment of the present invention. A vane pump 20 includes a cylinder body 22 having a cylinder hole 21 and cylinder covers 23 and 24 provided on both sides of the cylinder body 22. , Cylinder hole 2
1, a rotor 25 disposed inside 1, an eccentric shaft 26 that axially supports the rotor 25, and the rotor 2 via the eccentric shaft 26.
The motor 27 rotates 5 and a vane 28 provided in the cylinder body 22 so as to be retractable in the cylinder hole 21.

The rotor 25 has an outer diameter smaller than the inner diameter of the cylinder hole 21 and has an eccentric shaft 26 through a bearing 29.
The eccentric shaft 26 is supported by the cylinder covers 23 and 24 via bearings 30 and 31, and the motor 27 is provided outside the cylinder cover 24. Incidentally, 32 is a counter weight for smoothing the rotation of the rotor 25.

The vane 28 is provided in a vane groove 33 formed in the peripheral wall of the cylinder hole 21 so as to be movable in the radial direction of the cylinder hole 21, and its tip is slidably contacted with the outer circumference of the rotor 25.
A space formed between the peripheral wall of the cylinder hole 21 and the outer periphery of the rotor 25 is divided into a suction chamber 34 and a discharge chamber 35.

The cylinder body 22 has a suction passage 34a communicating with the suction chamber 34 and a discharge passage 3 communicating with the discharge chamber 35.
5a communicates with the discharge passage 35a in the middle to communicate with the vane groove 33.
And a pressure supply passage 35b opening to the back side of the vane 28 of the connecting pipe 3 is formed in the suction passage 34a.
6 is provided, a throttle valve 37 is provided as a flow rate control valve at the outlet of the discharge passage 35a, and the outer end of the pressure supply passage 35b is closed by a plug 38.

[0012] The vane pump 20 constructed in this way
The rotor 25, which rotates in the cylinder hole 21 by the motor 27, compresses the fluid in the suction chamber 34 while the rotor 25 rotates, and sends the fluid from the discharge chamber 35 to the discharge passage 35a.

Since the compressed fluid sent to the discharge passage 35a is provided with the throttle valve 37 at the outlet of the discharge passage 35a, the flow rate discharged from the outlet of the discharge passage 35a is limited. And the pressure of the fluid in the pressure supply passage 35b rises, and the pressure causes the vane 28 of the vane groove 33 to rise.
Is pressed from the back side to advance the vane 28 into the cylinder hole 21 and the tip of the vane 28 is brought into sliding contact with the outer periphery of the rotor 25.

The pressing of the vane 28 by the pressure of this fluid is continued until the next discharge stroke of the rotor 25. Then, as shown in FIG. 2, the fluid on the back surface of the vane 28 is
With the rotation of the rotor 25, the vane 28 moves the cylinder hole 2
The liquid is discharged from the outlet of the discharge passage 35a as it is immersed in one wall.

As described above, since the pressure of the fluid discharged by the rotation of the rotor 25 is used for pressing the vane 28, the pressing force of the vane 28 is stabilized and the sealing property between the tip of the vane 28 and the outer periphery of the rotor 25 is improved. In addition to the improvement, uneven wear of the vane 28 can be prevented, and the suction / exhaust efficiency of the vane pump 20 can be improved.

Therefore, even if the vane 28 is mounted on a vehicle which is subject to vibrations or the like caused by traveling, the vane 28 has no change in the pressing force and operates properly. Further, since the spring is not used to press the vane 28, the number of parts is reduced and the assembling becomes easy.

FIG. 4 shows a second embodiment of the present invention.
The same elements as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the vane pump 40, a discharge passage 41 communicating with the discharge chamber 35 is bent and formed, and the discharge passage 41 is formed in the vane groove 3.
No. 3 vane 28 is opened on the back side and the vane 28
A check valve 42 is provided as a flow rate control valve at the outer opening end of the discharge passage 41 formed on the back side of the check valve 42 so that the check valve 42 opens when the pressure of the fluid sent from the discharge chamber 35 exceeds a predetermined value. There is.

As a result, the vane 28 is pressed from the back side, and the tip of the vane 28 is brought into sliding contact with the outer periphery of the rotor 25, and the same effect as that of the first embodiment is obtained.

In each of the above embodiments, the throttle valve and the check valve are provided as the flow rate control valve.
A relief valve or solenoid valve may be provided,
Also, although the description has been given with the flow passage control valve provided in the discharge passage,
The flow control valve may be provided in the pipe connected to the discharge passage. Further, when an actuator or the like is connected to the discharge passage, the flow control valve may be omitted.

[0021]

As described above, in the vane pump of the present invention, the rotor which is pivotally supported by the eccentric shaft and rotates is provided in the cylinder hole formed in the cylinder body, and the vane formed in the peripheral wall of the cylinder hole is provided. A vane is provided in the groove so as to be retractable in the cylinder hole, and the tip of the vane is slidably contacted with the outer circumference of the rotor to define a suction chamber and a discharge chamber between the peripheral wall of the cylinder hole and the rotor. Since the tip of the vane is brought into sliding contact with the outer circumference of the rotor by the pressure of the fluid discharged by the rotation of the rotor in communication with the discharge chamber, the pressure of the fluid discharged by the rotation of the rotor is used to press the vane. The pressing force of is stable,
The sealability between the tip of the vane and the outer periphery of the rotor is improved, and uneven wear of the vane can be prevented.

Therefore, even if the vane is mounted on a vehicle in which vibration or the like is generated due to traveling, there is no change in the pressing force of the vane, and the vane operates properly. Further, since the spring is not used for pressing the vane, the number of parts is reduced and the assembling becomes easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of a main part of a vane pump showing a first embodiment.

FIG. 2 is a cross-sectional plan view of the main part of the same.

FIG. 3 is a sectional front view of the main part of the same.

FIG. 4 is a cross-sectional plan view of an essential part showing a second embodiment.

FIG. 5 is a cross-sectional plan view of a main part of a conventional vane pump.

FIG. 6 is a sectional front view of the same main portion.

[Explanation of symbols]

20, 40 ... Vane pump, 21 ... Cylinder hole, 22 ...
Cylinder body, 25 ... Rotor, 26 ... Eccentric shaft, 27
... Motor, 28 ... Vane, 33 ... Vane groove, 34 ... Suction chamber, 35 ... Discharge chamber, 35a, 41 ... Discharge passage, 35b ... Pressure supply passage, 37 ... Throttle valve, 42 ... Check valve

Claims (2)

[Claims] 1. A rotor that is pivotally supported by an eccentric shaft and rotates is provided in a cylinder hole formed in a cylinder body, and a vane can be retracted into the cylinder hole in a vane groove formed in a peripheral wall of the cylinder hole. In a vane pump provided with a tip end of the vane slidingly contacting the outer circumference of the rotor to partition an intake chamber and a discharge chamber between the cylinder hole peripheral wall and the rotor, a vane rear surface side of the vane groove and the discharge chamber are provided. A vane pump, characterized in that the tip of a vane is brought into sliding contact with the outer circumference of the rotor by the pressure of a fluid discharged in communication with the rotor. 2. The vane pump according to claim 1, further comprising a flow rate control valve provided in a discharge passage extending from the discharge chamber.