Surface Temperature Calculation and its Application for the Surface Fatigue Strength Evaluation of Rollers

Surface temperature is resulted by not only the load and dimension at the contact point but also the sliding velocity, rolling velocity, surface roughness, lubrication condition and etc. So, the surface fatigue strength of such as roller and gear may be evaluated more exactly and simply by use of the surface temperature or an index including the surface temperature than the Hertzian stress. In this research, the surface temperatures of rollers in different rolling and sliding conditions were measured with a thermocouple. The effects of the load P, mean velocity V_m and sliding velocity V_s on the surface temperature are clarified. An experimental formula, which expresses a linear relationship between the surface temperature and the P^0.86V_s^1.31V_m^−0.83 value, is presented to calculate the surface temperature. This formula is also confirmed available for the gear tooth surface temperature calculation by comparison of calculated temperature and the measured temperature on the gear tooth surface. The relationship between the surface temperature and the number of load cycles of rollers are investigated, the necessity and rationality of the surface fatigue strength evaluation considering the surface temperature are discussed.