Machine components such as bearings and gears are required to operate under severe tribological conditions such as elastohydrodynamic lubrication (EHL). There have been recent advances in techniques to improve sliding performance using coated films possessing superior tribological properties to reduce machine component failures. These techniques are often used under severe conditions such as elastohydrodynamic lubrication. In this paper, for coated film with interlayer and substrate used under elastohydrodynamic lubrication, distributions of oil film pressure, oil film thickness and stress distributions therein were numerically investigated in detail in consideration of traction acting on lubricated surface of coated film generated by lubricating oil flow. Also, the effects of lubricant properties on distributions of oil film pressure, oil film thickness and stress distributions were discussed. The typical results showed that maximum oil film pressure pmax, minimum oil film thickness hmin and maximum stress σmax of materials including coated film and interlayer when a paraffinic mineral oil is used are larger than those when a polyglycol synthetic oil is used.
