JPH0443875A - Vacuum pump of magnet type - Google Patents

Abstract

PURPOSE:To prevent exhaust air from remaining by forming the inner wall of a pump room into a curved surface in a dry vacuum pump of magnet type for obtaining dry high vacuum. CONSTITUTION:Air is sucked into a first stage pump room 7 through an inlet valve 6. Then the polarity of a coil mounted around a first stage core 4 is changed so as to cause a diaphragm 2 to move downward and air sucked into the first step pump room 7 is fed into a second stage pump room 8 accordingly. In this case, movement of the air from the first stage pump room 7 to the second stage pump room 8 is achieved through the center hole 9 of the diaphragm. When the diaphragm 2 is moved downward a built-in diaphragm 1 is separated from the upper portion of the diaphragm 2 so the center hole 9 is opened. When the diaphragm 2 is moved upward the built-in diaphragm 1 makes sealing contact with the upper portion of the diaphragm 2 so the center hole 9 is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnet type dry vacuum pump.

[Background of the invention]

Conventionally, as shown in FIG. 3, when the motor 1 rotates, the connecting rod 3 moves up and down by the amount of eccentricity of the crankshaft 2.

When the connecting rod goes down, air 5 is sucked in through the intake port 4, and when the connecting rod goes up, the air is compressed, pushes up the exhaust valve 6, and is exhausted. Since all the air cannot be exhausted during the exhaust stroke, air remains and the ultimate pressure decreases. In order to increase the displacement, the area of the diaphragm must be increased. However, there are limits to the strength and movable distance of the diaphragm, so it is not possible to increase the displacement. Therefore, when it is desired to increase the displacement, parallel operation is required, which has the disadvantage of requiring a larger vacuum pump. Because lubricating oil such as grease was used in the pump and motor bearings,
Difficult to start at low temperatures.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art.
The goal is to create a dry, high vacuum, and compact vacuum pump.

[Summary of the invention]

In the present invention, a magnet is built into a diaphragm, and the diaphragm is moved up and down by changing the polarity of an external magnetic field to perform a pumping action. In addition, it has a multi-stage structure to obtain a dry high vacuum.

[Embodiments of the invention]

As shown in FIG. 1 and FIG.
A pump chamber is formed by sandwiching the upper and lower surfaces of the outer periphery of the diaphragm between the stage cores 4.

Air 5 is drawn into the first stage pump chamber 7 through the intake valve 6. Next, by changing the polarity of the coil attached to the first stage core, the diaphragm is moved downward, and the air that has been sucked into the first stage pump chamber is sent into the second stage pump chamber 8. At this time, air movement from the first stage pump chamber to the second stage pump chamber is performed through the diaphragm center hole 9. When the diaphragm moves downward, the built-in magnet and the top of the diaphragm separate, opening a center hole. When the diaphragm moves upward, the built-in magnet and the top of the diaphragm come into contact and seal, closing the center hole.

The movement of air from the second stage pump chamber to the third stage pump chamber 10 is performed in the same manner. The air is then exhausted to the atmosphere from the final stage exhaust port 11.

Each pump chamber is stacked and tightened with bolts 12.

〔Effect of the invention〕

According to the present invention, since the inner wall of the pump chamber has a curved surface, the diaphragm can exhaust the air along the curved surface, so that no air is left unexhausted, and since a multi-stage structure can be formed, the ultimate pressure can be improved.

No lubricating oil such as grease is used in the pump or drive source, and since there are no sliding surfaces, no abrasion powder is generated, resulting in a clean vacuum. Additionally, since no lubricating oil such as grease is used, low temperature startup is easy.

The pump can be easily assembled and disassembled, so maintenance is easy. Also, by stacking the pump chambers, it can be made multi-stage, making it more compact.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the present invention, FIG. 2 is a top view of the present invention,
FIG. 3 is a longitudinal sectional view of the prior art. 1 is a magnet, 2 is a diaphragm, 3 is a rectangular coil, 4 is a first stage core, and 6 is an intake valve. Name of patent applicant Hitachi Koki Co., Ltd.

Claims (1)

[Claims] A pump chamber is formed by sandwiching the upper and lower circumferential surfaces of a diaphragm with a built-in magnet between a core with a rectangular ring-shaped coil, and by changing the polarity of the coil, the diaphragm is moved up and down to perform a pumping action, and the components can be moved in multiple stages. A magnetic vacuum pump that allows you to obtain a dry high vacuum.