Motor shaft voltage testing structure

Abstract

The invention belongs to a motor testing structure, and particularly relates to a motor shaft voltage testing structure. The motor shaft voltage testing structure comprises an end cover arranged at a non-transmission end of a rotating shaft, an electric brush, a shaft sleeve and an electric brush fixing frame, wherein the end of the rotating shaft is installed in the end cover through a bearing; a shaft sealing ring is arranged between the end cover and the rotating shaft; an outer cover is arranged on the end face of the end cover; a penetrating hole is formed in the outer cover; the shaft sleeve penetrates through the penetrating hole to be fixed to the end face of the rotating shaft; one end of the electric brush fixing frame is fixed to the end cover, and the other end of the electric brush fixing frame extends to the shaft sleeve and is fixedly provided with an insulating sleeve; and the electric brush is arranged in the insulating sleeve and abuts against the shaft sleeve. According to the invention, the electric brush fixing frame is fixed to the end cover located at the non-transmission end, and is cooperated with the shaft sleeve extending from the end of the rotating shaft, so the electric potential of a motor shaft side can be tested in a limited space environment; and the outer cover and the shaft sealing ring ensure the internal sealing performance of the motor, the outer cover is provided with a through hole, and the shaft sleeve is led out through the through hole, so assembling can be completed in a narrow space.

Description

technical field [0001] The invention belongs to a motor testing structure, in particular to a motor shaft voltage testing structure. Background technique [0002] With the development of power electronics technology, power converters using pulse width modulation technology (PWM) are widely used in motor drive systems. The application of high-speed switching devices with IGBT as the core speeds up the dynamic response time of the power converter and improves the operating performance of the system. However, the high-frequency common-mode voltage generated by the frequency converter will induce a high-amplitude bearing voltage on the motor shaft, and form a shaft current, which will damage the motor bearing in a short time and shorten the service life of the motor. [0003] At present, there are four ways to eliminate the shaft voltage: (1) use ceramic roller bearings; (2) use outer ring insulated bearings; (3) choose the most suitable grease according to the motor's operatin...

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Problems solved by technology

[0005] In order to overcome the problem that the existing structure cannot measure the shaft voltage in a narrow space without damaging the sealing performance of the motor, the present invention proposes a motor shaft voltage test structure, which is compact, simple, low in cost, simple in maintenance, and applied Wide field

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