An Influence of Atmospheric Humidity and Temperature on Brush Wear of Sliding Contact

Takahiro UENO  Koichiro SAWA  

IEICE TRANSACTIONS on Electronics   Vol.E83-C    No.9    pp.1395-1401
Publication Date: 2000/09/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Current Electromechanical Devices and Their Materials with Recent Innovations)
surface film,  brush wear,  contact voltage drop,  lubrication,  

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At the sliding contact of brush and rotating slip-ring or commutator, it has been recognized that the brush wear is influenced by brush pressure, current density and atmosphere nearby contact part. However, little is known about the relation between brush wear and atmosphere condition in detail. In this paper, the experiments are carried out with a great attention to the effect of surrounding temperature and humidity on brush wear. The sliding part of brush and slip-ring is put on the sealed box and the atmosphere in the sealed box is kept on the specified condition by temperature and humidity control system. The brush wear, contact voltage drop and slip-ring surface morphology are observed after the sliding test. From these results, in both cases of the high humidity (nearby 80%) and low humidity (nearby 20%), the brush wear are large. And the brush wear rate is the lowest around 60% relative humidity. However, the characteristics of brush wear under the 15C is not similar to others. When the surrounding temperature is changed, in case of the 20% humidity, the brush wear increases with increasing surrounding temperature. On the other hand, in case of 80% humidity, the brush wear increases with decreasing surrounding temperature. Consequently, the results clearly shows that the temperature and humidity not only affect the brush wear but also change the condition of the film formation on slip-ring.