Abstract:Point contact mixed lubrication model for crowed modified gear was established based on the average Reynolds equation and Zhao-Maietta-Chang(ZMC)elastic-plastic contact model.Lubrication characteristic parameters were calculated by progressive mesh densification method.The correctness of proposed model was verified by comparing with the simulation results of steady-state point contact mixed lubrication model.The lubrication characteristics of engaging-in,pitch and engaging-out point were investigated.Effects of gear geometrical parameters,operating parameters on crowed modified tooth surface lubrication characteristics were analyzed.The results show that film pressure,contact pressure and total pressure are the largest at engaging-in point,and the minimum at engaging-out point.Nominal film thickness is the largest at engaging-out point and the smallest at engaging-in point.With the increase of modulus,pressure angle and rotating speed,the film pressure,asperity contact pressure and total pressure decrease,and the oil film thickness increases.As the power and crowned modification increase,the oil film pressure,asperity contact pressure and total pressure increase,and the oil film thickness decreases.Therefore,the rough tooth surface lubrication state can be improved by increasing modulus,pressure angle and speed,and reducing power and crowned modification.