Evaluating the influence of tooth surface wear on TVMS of planetary gear set

Time-varying mesh stiffness (TVMS), one of the most important parameters in gear dynamics, is usually used to analyze the influence of gear fault in gear transmission systems. In this study, a modified TVMS model is proposed to quantitatively evaluate the influence of the tooth wear on the mesh stiffness. In this model, the potential energy method is employed to calculate the mesh stiffness and the Archard's wear equation is adopted to calculate the tooth wear depth. Furthermore, the analytical expression of the modified mesh stiffness considering the tooth wear is theoretically derived, which can be used for a variety of tooth wear models. The modified TVMS model is applied in a planetary gear set, including the sun-planet mesh and the planet-ring mesh. The results of numerical simulation demonstrate that the tooth wear can result in the reduction of the mesh stiffness; for a planetary gear set, in the initial wear process, the mesh stiffness decreases proportionally when the tooth wear depth increases.