Dynamic wear evolution analysis of spur gear considering tribo-dynamic effect

Gear wear is an inevitable form of damage during long-term operation. However, current research on gear wear prediction primarily relies on quasi-static conditions, which neglects the reciprocal influence of dynamic tooth loads and friction. To address this gap, a dynamic wear evolution model is proposed by integrating sub-models of tooth-loaded contact, gear thermal-elastohydrodynamic lubrication (TEHL), modified gear wear, and gear tribo-dynamic effects. This model not only enables accurate prediction of tooth flank wear evolution but also captures the reciprocal effect of dynamic tooth loads and tribological behavior. The results indicate that gear wear predicted by the dynamic model is more severe than that by the static model. As transmitted load and operating speed increase, this discrepancy becomes more pronounced. This phenomenon is attributed to the decrease in time-varying mesh stiffness and the increase in loaded static transmission error excitation as gear wear accumulates, which in turn leads to higher dynamic tooth loads and friction forces. Additionally, gear wear further exacerbates the system dynamic response. As wear accumulates, the gear pair tends to enter chaotic motion more readily, manifested in phenomena such as tooth contact separation or back contact. These behaviors induce violent vibrations and a significant reduction in the transmission stability of the gear pair.