JPS6118234Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vane type non-lubricated vacuum pump.

This type of vane pump has recently been widely used in industrial machinery due to its advantages such as small size, light weight, low noise, and low vibration.

Conventionally, in this type of pump, a groove is provided on the inner wall surface of the side housing in the suction stroke area to connect the vane groove space and the suction chamber, thereby reducing the negative force generated in the vane groove space when the vane protrudes radially outward. Efforts have been made to alleviate the pressure and thereby improve the vane's ability to follow the inner wall surface of the rotor housing.

On the other hand, in the discharge stroke region, especially in non-lubricated vacuum pumps, if a liquid such as oil is sucked in and enters the bottom of the vane groove, the liquid is compressed by the vane trying to enter radially inward, causing a significant This generates high pressures that prevent smooth entry of the vanes, sometimes even leading to damage to the vanes or rotor.

Therefore, it is conceivable to provide a through hole in the side housing wall corresponding to the vane groove space in the stroke area to allow the high pressure liquid to escape to the outside, but this case has the following problems.

First, a check valve is required at the outlet of the through hole to prevent foreign matter from entering the working chamber from the outside through the through hole, but in order to install such a check valve, the side housing must be installed. It is necessary to provide a case to accommodate the check valve on the outside of the pump, making the pump large. Further, when a plurality of through holes are provided, it is necessary to install a check valve for each through hole, making the device complicated.

The present invention provides a vane type non-lubricated vacuum pump of this type that skillfully solves the above-mentioned defects. An annular valve, a wave spring that supports the annular valve, a stopper ring that supports the wave spring, and a bearing are arranged toward the annular valve, and a plurality of communication holes that communicate the vane groove space and the annular valve in the discharge stroke area. is provided on the inner wall of the side housing, and a hole is provided in the side housing to communicate the space surrounding the drive shaft with the atmosphere.

The gist of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an example of a vane type non-lubricated vacuum pump of the present invention, and FIG. 3 shows an enlarged view of the main parts. Here, 2 is a rotor housing, 3 and 3 are side housings, 4 is a rotor rotated by a drive shaft 5, 51 and 52 are bearings, and 6 is a vane that is slidably installed in a vane groove provided in the rotor 4. ,7
2 is a vane groove space formed by the vane groove, the vane back surface 61, and the side housing 31, 20 is a communication hole corresponding to the vane groove space 7, and 21 is a communication hole 2.
0 is an annular valve, 22 is a wave spring that supports the annular valve 21, 35 is a space that accommodates the annular valve 21, 30 is a hole that communicates the space 35 with the outside, and 24 is a wave spring 22.
Shows the stopper ring that supports the.

FIG. 2 is a supplementary drawing to FIG. 1, and is a cross-sectional view taken at - in FIG. 1.

The chain lines indicate the rotor 4, the vane groove space 7, and the communication hole 20.
It shows the position of

9 indicates a suction stroke region, and 12 indicates a discharge stroke region.

The operation of the vane type non-lubricated vacuum pump of the present invention will be explained below.

By providing a groove connecting the vane groove space and the suction chamber on the inner wall surface of the side housing in the suction stroke area, negative pressure generated in the vane groove space when the vane protrudes radially outward is alleviated. Since such a configuration is not an essential part of the present invention, it is not shown in the drawings.

First, when the rotor 4 rotates and starts sucking fluid, the vane groove space 7 in the discharge stroke area 12 is filled with the vane 6.
Compressed by

At that time, if liquid such as oil accumulates in the vane groove space 7 and abnormally high pressure occurs, it passes through the communication hole 20 corresponding to the vane groove space 7 and the wave spring 2
2, the annular valve 21 is opened and the liquid is released into the space 35.

The liquid that has flowed into the space 35 is discharged through the hole 30 that communicates with the outside.

The pump is operating normally and the discharge stroke area 12
The vane groove space 7 corresponding to is at a relatively low pressure,
In addition, when the pressure is such that the normal operation of the pump is not hindered by the excessive protrusion force of the vane, the annular valve 21 is closed by being pressed by the wave spring 22 which has adjusted the pressing force, and the communication hole 20 is closed. Foreign objects will not enter from outside the street.

The vane type non-lubricated vacuum pump of the present invention described above can achieve the following effects.

That is, as described in the explanation of the operation, the abnormally high pressure in the vane groove space 7 is quickly released, and the vane 6
There is no damage at all. Next, an annular valve 21 that acts as a check valve for the communication hole 20 and a wave spring 22 are connected to the drive shaft 5.
Because of the structure surrounding the annular valve 21, the space 35 for accommodating the annular valve 21 is small, and the complexity and enlargement of the side housing 3, such as providing a space, can be avoided.

Further, by using grease filled type bearings 51 and 52 to protect the bearing 51 and fitting an oil seal 53 to the shaft, the influence of foreign matter entering the space 35 from the outside can be prevented.

As described above, the vane type non-lubricated vacuum pump of the present invention has no vane damage, is small in size, and is free from foreign matter contamination from the outside.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the pump of the present invention, FIG. 2 is a cross-sectional view taken from FIG. 1, and FIG. 3 is an enlarged view of the main part of FIG. Explanation of numbers, 3...Side housing, 31...
...Inner wall surface, 4...Rotor, 5...Drive shaft, 6...
... Vane, 7 ... Vane groove space, 12 ... Discharge stroke area, 20 ... Communication hole, 21 ... Annular valve, 22 ...
...Wave spring, 51...Bearing, 30...Hole.

Claims (1)

[Scope of utility model registration request] A rotor is supported in a rotor chamber formed by a rotor housing and a pair of side housings, and vanes are slidably provided in each of a plurality of vane grooves of this rotor, and fluid is sucked by vane action as the rotor rotates. In a vane type non-lubricated vacuum pump that performs compression and discharge, an annular valve and a corrugated shape supporting the annular valve extend axially outward in a space forming around the drive shaft in the side housing. A spring, a stopper ring for supporting the wave spring, and a bearing are arranged, and a plurality of communication holes are provided in the inner wall of the side housing to communicate the vane groove space and the annular valve in the discharge stroke region, and the circumference of the drive shaft is formed. A vane type non-lubricated vacuum pump characterized by having a hole in the side housing that communicates the space between the air and the atmosphere.