Oil-sealed vane rotary vacuum pump

Abstract

An oil-sealed vane rotary vacuum pump includes at least one pump stage arranged in the housing and having a cylindrical chamber, a shaft excentrically arranged in the cylindrical chamber and provided with vanes, and a drive for driving the shaft and having a plurality of permanent magnets arranged on the shaft and stationary electrical coils surrounding the permanent magnets and producing a rotatable magnetic field, and control electronics for controlling the coils and arranged in a removable housing part of the pump.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an oil-sealed vane rotary vacuum pump including a housing, at least one pump stage arranged in the housing and having a cylindrical chamber, a shaft excentrically arranged in the cylindrical chamber and provided with vanes, and drive means for driving the shaft. [0003] 2. Description of the Prior Art [0004] Vane rotary vacuum pumps play an important role in generation of vacuum. They are used to generate low and high vacuum with an end pressure up to about 6*10−3 mbar and are used in industry, research, and laboratories. Traditionally, these pumps are used as for vacuum pumps for pumps such as Roots vacuum pumps and turbomolecular pumps which are not sealed against the atmospheric pressure. Dependent on their use, they are formed as one stage or multi-stage pumps. [0005] The vane rotary vacuum pumps of the type described above belong to a class of oil-filled positive displacement pum...

AI Technical Summary

Benefits of technology

[0013] According to the invention, the oil-sealed vane rotary vacuum pump is equipped with brushless direct current motor that consists of permanent magnets arranged on the shaft of the pumping system, and stationary coils which are controlled by the control electronics. These motors have a very uniform relationship between the torque and rotational speed and rotational angle. Thus, already at a very low rotational speed, the motor starting torque is brought up to almost a full torque. Thereby, a motor can be used that has, in comparison with an asynchronous alternating current motor, a uniform torque and a noticeably reduced power consumption. In addition, the motor has reduced dimensions and, therefore, the pump itself can be formed more compact. Further, the uniform torque provides for a noticeably quieter running, which positively influences the vibration and noise. Further, instead of several shafts used in conventional pumps, only one shaft is used, which reduces the manufacturing costs and the danger of failure.

Problems solved by technology

Further, the uniform torque provides for a noticeably quieter running, which positively influences the vibration and noise.

Further, instead of several shafts used in conventional pumps, only one shaft is used, which reduces the manufacturing costs and the danger of failure.

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