Experimental Research on Current-Carrying and Friction Characteristics of Sliding Electrical Contact

In order to prolong the service life of electric locomotive frictional pair, which consists of copper-tin alloy contact wire and immersed copper carbon pantograph slide, a high performance sliding electrical contact testing machine was developed. It not only can adjust contact pressure, contact current and sliding speed continuously in a certain scope, but also has the function of real time monitoring experimental parameters. Lots of current-carrying friction experiments were done by using the testing machine under different contact pressures, sliding speeds and contact currents. The results show that friction coefficient and contact current characteristics appear the dynamic fluctuation similarly in the same experimental condition. According to the experimental results, the friction process is divided into running-in period and relative-stable period by the authors. Through reading a large number of references, current-carrying efficiency and two coefficients of variation which are coefficient of variation of friction and coefficient of variation of current were put forward, then some rules between the current-carrying friction characteristics and contact pressure, sliding speed and contact current were summarized.