JPS6126639Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an oil rotary vacuum pump in which a pump casing is disposed below the oil level in an oil reservoir, and a vaned rotor that performs the pump function is housed within the pump casing. It is.

In this type of oil rotary vacuum pump, in order to be able to achieve a high vacuum through the so-called oil ballast effect, the oil in the oil reservoir is fed into the pump casing little by little during operation. There is.

However, simply guiding the oil in the oil reservoir into the pump casing will result in contaminants such as dirt and dust mixed in the oil being brought into the pump casing, so precision machining is required. This has the disadvantage that it adversely affects various parts inside the pump casing, resulting in a decrease in pump performance or failure. For this reason, some devices use net-like filters to remove impurities, but such filters have the disadvantage of clogging unless they are frequently cleaned.

By the way, recently, as one of this type of oil rotary vacuum pump, one end of the rotating shaft that supports the rotor is made to penetrate through one side wall of the pump casing and protrude into the oil reservoir. It has been proposed that a starting end of an oil supply passage communicating with the inside of the pump casing is opened on the outer circumferential surface of the pump casing, and the starting end opening is opened and closed by a centrifugal valve mechanism provided on the rotating shaft. However, this pump
It is unique in that the oil in the oil reservoir is taken in from one end of the rotating shaft that rotates at high speed.

The present invention was developed using such a special oil intake structure, and has a simple structure in which a centrifugal separation case that rotates together with the rotating shaft is provided at one end of the rotating shaft with the starting end of the oil supply path open. This allows contaminants to be reliably separated and removed from the oil supplied into the pump casing, and the desired pump performance can be maintained over a long period of time without the need for special maintenance or inspection work. The present invention provides an oil rotary vacuum pump as described above.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A cylindrical pump casing 3 is disposed below the oil level in an oil reservoir 2 in which a certain amount of oil 1 is stored, and a rotor with vanes 4 that perform a well-known pump function is located at an eccentric position within the pump casing 3. It accommodates 5. Then, one end of the rotating shaft 6 that supports the rotor 5 is made to penetrate through one side wall 3a of the pump casing 3 and protrude into the oil reservoir 2, and the outer circumferential surface of the protruding end 6a of the rotating shaft 6 is The starting end of the oil supply path 7 communicating with the inside of the pump casing 3 is opened. The oil supply passage 7 includes a vertical oil passage 7b formed at the axial center of the rotating shaft 6, and first horizontal oil passages 7c, 7c that open the vertical oil passage 7b on the outer peripheral surface of the protruding end 6a. The vertical oil passage 7
a second horizontal oil passage 7d that opens at the bottom surface of the vane holding groove 5a of the rotor 5; and a third horizontal oil passage 7d that opens the vertical oil passage 7b at a portion near the bearing member 9 on the outer peripheral surface of the rotating shaft 6. It consists of a horizontal oil passage 7e. The starting end openings 7a, 7a of the oil supply path 7 are opened and closed by a centrifugal valve mechanism 11. The valve mechanism 11 has its distal end surface in contact with the outer circumferential surface of the rotating shaft 6, and opens the starting end opening 7a of the oil supply path 7.
Valve bodies 11a, 11a that close the valve body 7a, and a weight 11 that holds the proximal ends of the valve bodies 11a, 11a.
b, 11b, and the weights 11b, 11 at the free end.
These weights 11b and 11
a U-shaped spring 1 that urges the valve bodies 11a, 11a toward the outer peripheral surface of the rotating shaft 6 via b;
1c, and the center portion of the spring 11c is fixed to the tip end surface of the rotating shaft 6 using a screw 11d. Further, starting end openings 7a, 7 of the oil supply path 7 are provided at the protruding end 6a of the rotating shaft 6.
A and a centrifugal separation case 12 surrounding the valve mechanism 11 are mounted so as to be rotatable together with the rotating shaft. The centrifugal separation case 12 has an open end connected to the rotation shaft 6.
It is a cup-shaped piece that is fitted onto the outer periphery of a flange 6b formed on the outer periphery of the end wall 12a, and an oil introduction hole 12b is bored in the center of the end wall 12a, and the largest diameter part of the peripheral wall 12c, for example, near the opening end. A plurality of contaminant discharge holes 12d are bored in the section.

With such a configuration, when the pump starts operating and the rotational speed of the rotating shaft 6 exceeds a certain value, the centrifugal force acting on the valve bodies 11a, 11a of the valve mechanism 11, the weights 11b, 11b, etc. overcomes the biasing force of the spring 11c and each valve body 11
a, 11a are separated from the outer peripheral surface of the rotating shaft 6, the oil supply passage 7 is brought into communication, and the oil 1 in the oil reservoir 2 is supplied into the pump casing 3 through the oil supply passage 7. Moreover, in the vacuum pump according to the present invention, the centrifugal separation case 12, which has the oil introduction hole 12b in the end wall 12a and the contaminant discharge hole 12d in the peripheral wall 12c, is connected to the starting end opening 7a of the oil supply path 7. , 7a and the valve mechanism 11 so as to be integrally rotatable with the rotating shaft 6. Therefore, the oil 1 introduced into the centrifugal separation case 12 through the oil introduction hole 12b is guided to the starting end openings 7a, 7a of the oil supply path 7 while undergoing centrifugal separation within the case 12. . As a result, impurities 1a mixed in oil 1
is collected at a position along the inner surface of the circumferential wall 12c of the centrifugal separation case 12 and returned to the outside of the case 12 through the contaminant discharge holes 12d provided in the circumferential wall 12c. Then, only clean oil 1 is led to the oil supply path 7 and supplied into the pump casing 3. Therefore, with such a device, it is possible to reliably separate and remove the impurities 1a from the oil 1 supplied into the pump casing 3, and there is no need for special maintenance and inspection work as in the case of using a filter. The desired pump performance can be maintained over a long period of time without the need for Also, this thing is simply centrifuge case 1
2 is simply attached to the protruding end 6a of the rotary shaft 6, the structure is simple and easy to implement.

It should be noted that the configuration of the centrifugal separation case is of course not limited to the one described above; for example, the configuration of the centrifugal separation case is
It may be as shown in the figure. That is,
The centrifugal separation case 12' shown in FIG.
Contaminant discharge holes 12'd are provided near the end wall 12'a at 2'c. Further, in the centrifugal separation case 12'' shown in FIG. 4, the inner circumferential surface of the peripheral wall 12''c is tapered, and contaminant discharge holes 12''d are provided at the maximum diameter portion of the peripheral wall 12''c.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the present invention;
Figure 2 is a sectional view taken along the - line in Figure 1;
4 are partial cross-sectional views showing other embodiments of the present invention. 1...Oil, 1a...Contaminants, 2...Oil reservoir, 3...Pump casing, 4...Vane,
5... Rotor, 6... Rotating shaft, 6a... Projecting end, 7... Oil supply path, 7a... Starting end opening, 11...
... Valve mechanism, 12, 12', 12" ... Centrifugal separation case, 12a, 12'a ... End wall, 12b ... Oil introduction hole, 12c, 12'c, 12"c ... Peripheral wall, 12
d, 12'd, 12''d...Contaminant discharge hole.

Claims (1)

[Scope of utility model registration request] A pump casing is disposed below the oil level in the oil reservoir, a vaned rotor that performs a pump function is housed in the pump casing, and one end of the rotating shaft supporting the rotor is attached to one side wall of the pump casing. is penetrated to protrude into the oil reservoir, and a starting end of an oil supply passage communicating with the inside of the pump casing is opened at the outer circumferential surface of the protruding end of the rotating shaft;
In a vacuum pump in which the starting end opening is opened and closed by a centrifugal valve mechanism provided on the rotating shaft, a centrifugal separation case surrounds the starting end opening of the oil supply path and the valve mechanism at the protruding end of the rotating shaft. 1. An oil rotary vacuum pump, characterized in that an oil rotary vacuum pump is mounted so as to be rotatable integrally with the rotary shaft, an oil introduction hole is provided in the end wall of the case, and a contaminant discharge hole is provided in the peripheral wall.