A calculation method of differential planetary gear meshing efficiency based on dynamic load-friction coefficient coupling iterative

To solve the problem of inaccurate efficiency calculation caused by the coupling effect between dynamic characteristics and tooth surface friction in traditional calculation. In this paper, Based on the friction contact boundary of mixed elastohydrodynamic lubrication, the friction coefficient expression of coupled dynamic load is derived, the dynamics-tribology coupling iterative model of gear system is constructed, and a new meshing efficiency calculation method for gear dynamic loads-friction coefficient coupling iterative is proposed. The coupling iterative model solving algorithm is developed and compared with the meshing efficiency calculation results of the traditional efficiency calculation and the AGMA standard. The effects of dynamic characteristics, friction characteristics and lubrication characteristics on meshing efficiency under the coupling of dynamics and tribology are analyzed. The research indicates that the friction coefficient considering dynamic loads exhibits significant fluctuations compared to traditional values, leading to amplitude variations of the efficiency considering the iterative effect of dynamic load compared with the efficiency without considering the dynamic load. As rotational speed increases, the differences between dynamic load distribution characteristics and steady-state load distribution become more significant. As the surface roughness amplitude increases, the gear meshing efficiency decreases, thereby reducing the differential planetary gear transmission efficiency. This study has important theoretical significance to improve the transmission efficiency of differential planetary gear system.