Abstract:To study the effect of tooth surface wear on the timevarying mesh stiffness of gear pairs,by considering the gear tooth side clearance,transmission error and tooth surface wear,the gearshifttorque nonlinear dynamic model was established by the lumped parameter method.The effect of the gear speed and the number of runs on the dynamic characteristics of a gear train with tooth surface wear was analyzed.The results show that in the meshing area,the wear of the tooth surface at the root of the tooth is decreased,the wear of the tooth at the node is zero,and the wear of the tooth surface at top of the tooth is increased.The decreasing trend of the tooth surface wear is greater than the increasing trend.During the whole process,the tooth surface wear will cause the reduction of meshing stiffness.In the case of tooth surface wear,too large or too small rotation speed will increase the amplitude fluctuation of the gear system and decrease the amplitude.When the speed is constant,with the increase of operating times,the amplitude of the system with tooth surface wear will gradually decrease and the transmission fluctuation will be intensified.