Vacuum pump

Abstract

A vacuum pump includes shaft, two spaced from each other, dynamic gas bearings for supporting the shaft for rotation, and a pumping system arranged on the shaft between the two gas bearings and having two pumping sections which are so formed that compressed gas from each section is delivered in a direction of a gas bearing adjacent to this pumping section.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a vacuum pump having a shaft supported for rotation by two radial bearings, and a pumping system arranged on the shaft.[0003]2. Description of the Prior Art[0004]In many technical fields, the production of a high vacuum with pressures lower than 10−4 mbar is of great importance. There is an increasing need in compact vacuum pumps capable of producing such pressures. In the state of the art, however, often, pumping stations are used. In the pumping stations, several separate pumps, which are adapted to particular pressure regions, are combined. Recently, vacuum pumps dischargeable into atmosphere have been developed. In these pumps, several pumping principles are combined. E.g., the German Publication DE 199 30 952 A1 proposes to combine Holweck pumping stages with peripheral stages. However, the proposed construction, because of its rather high costs, is only attractive for class of pump...

AI Technical Summary

Benefits of technology

[0007]The provision of gas bearings permits to simplify the pump construction. Gas bearings do not require any organic lubricant so that a lubricant circuit with a lubricant pump can be eliminated, and no contamination of a recipient and the pumped gas can occur. Gas bearings are subjected to very little wear, which permits to achieve an extended service life of the pump, together with substantially reduced maintenance costs. The construction of the pump is simplified due to a favorable gas guidance.

[0016]According to the present invention, the rotor and the stator of the drive motor of the vacuum pump are so formed that they provide for an axial centering and, simultaneously, a rapid rotation of the shaft. This permits to eliminate the need for axial bearings, which further contributes to cost-effectiveness and compactness of the inventive vacuum pump.

Problems solved by technology

However, the proposed construction, because of its rather high costs, is only attractive for class of pumps having a suction capacity above 20 m3 / hr.

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