Based on a camroller mechanism of an internal combustion engine,the corresponding numerical model of elastohydrodynamic lubrication was established,and the lubrication state during the rotating cycle of the cam was obtained.The influence of the roller convexity,the oil viscosity and the slipping between the cam and the roller was analyzed.The results show that the lubrication state of the camroller contact can be divided into fluctuation period and stationary period,which correspond to the changing law of cam lift.The roller convexity can affect the lubrication state of the contact pair,and the pressure distribution in the contact zone is very sensitive to it.To some extent,increasing the viscosity of the oil can optimize the pressure distribution in the contact zone and improve the lubrication state.However,the slipping phenomenon of the cam and the roller can reduce the film thickness of the contact zone,especially the influence on the temperature rise and friction coefficient of lubricating oil is more significant.