Investigation of the electrical rolling contact degradation based on fractal theory

Rotary electrical connector is one of the key components for power source and electrical equipment connecting with rotating electrical interfaces, such as artificial space station, earth satellite, radar, wind generator, etc. Rolling contact connector (RCC) is a competitive technology compared to traditional sliding connectors for rotary electrical connecting, especially for long-life applications. In this paper, a novel coupled rolling contact structure of RCC prototype is presented. The degradation of rolling electrical contact is studied experimentally. Scanning electron microscope and confocal laser scanning microscope are utilized to obtain the gradual changes of the microscopic morphology and elemental composition on the rolling contact surfaces. A mathematical model of electrical contact based on fractal geometry is introduced to describe the contact behavior of RCC. Numerical analysis results illustrate the fractal dimension can be used as a key parameter to characterized the wear pattern. The mechanism of rolling electrical contact degradation is discussed in detail.