Abstract:Aimed at the problems of premature gluing and wear of cam mechanisms under mixed elastohydrodynamic lubrication(EHL),the lubrication characteristics of cam tappet pairs under mixed EHL were studied.Based on the idea of load sharing,the parameter equations of cam mechanisms and the theory of EHL were combined,the friction coefficient,film thickness and load bearing ratio of oil film in the pushing course of cam mechanisms were solved by numerical method.The curves of friction coefficient,film thickness and load bearing ratio of oil film of cam mechanisms varying with cam rotation of six motion laws were obtained,and the effects of radius of base circle,equivalent modulus of elasticity and rotating speed on the lubrication characteristics of cam mechanisms were studied.The results indicate that increasing the radius of the base circle and rotating speed is beneficial to reducing the friction coefficient in the pushing course,and increasing the film thickness and the load bearing ratio of the oil film,which is beneficial to improving the lubrication condition.Increasing the equivalent modulus of elasticity has little effect on the film thickness in the pushing course,but it will increase the friction coefficient and reduce the load bearing ratio of oil film,which is not conducive to the improvement of lubrication condition.