Abstract
Using a two-roller testing machine, the rolling contact fatigue life of bearing steel rollers with mirror-like smooth surfaces was examined. A pair of rollers were driven under the rolling with sliding condition of s=-3.2%, and a maximum Hertzian stress in the range of PH=3.0GPa〜4.0GPa was applied in point contact condition. As lubricant, a low viscosity synthetic traction oil with viscosity grade of ISO VG 32 was used, and the test results were compared with those obtained using a low viscosity mineral oil with almost the same viscosity grade. Consequently, the fatigue life with a low viscosity traction oil was shorter than that with a low viscosity mineral oil, and this tendency appeared more distinctly under higher stress conditions above PH=3.4GPa. Based on the numerical calculation results of the thermal EHL, the authors discuss the mechanism which causes such a difference in the fatigue life.
