Experimental Study Of EHL Friction Under Big Slide-Roll Ratio Conditions

Gears and bearings that work in EHL are commonly used in machine industry, and their lubrication and friction characteristics have significant effect on the performance and the service life of mechanical equipments. Numerical calculations of EHL are extensive at present. By contrast, experimental study on EHL friction, especially on EHL friction under big slide-roll ratio conditions is in lack. Therefore, experimental study of EHL friction under big slide-roll ratio conditions is of significance not only to production practice but also to theoretical study.According to the actual operating parameters of line contact elements, this paper at first modified the existing JPM-1 two-disc contact fatigue friction and wear tester, a sensor was added for friction coefficient measurement. A series of EHL friction experiments were conducted under two conditions -moderate loads and heavy loads on the self-modified JPM-1 two-disc tribo-tester. A large amount of EHL friction coefficients under different conditions were obtained, and the relationship between friction coefficient and load, slide-roll ratio and the rolling speed was obtained from the analysis of the experimental results. Explanations were given from many aspects for the change of EHL friction coefficient with different operating parameters.For further study on the relationship between EHL friction coefficient and different operating parameters, the EHL film thickness was calculated with a proper formula, and the influence of working conditions on EHL film thickness was analyzed.