Nonlinear dynamics of gear transmission with an improved wear model

Abstract

Gear teeth wear is an inevitable fault in the gear transmission system, which will change tooth profile shape, tooth contact behavior, and system response. Traditional tooth wear models have limited accuracy because they neglect both the worn tooth profile’s effect on contact pressure or the varying sliding distances of discretized points on the tooth profile. Therefore, an improved teeth wear model is proposed, considering the asymmetric contact pressure distribution and pressure concentration caused by worn teeth or corner contact, along with a new sliding distance computation method that addresses overlapping contact spots. Subsequently, the interaction between the teeth wear and gear meshing models is realized through iterative updates of the worn tooth profile, wear depth, and tooth contact force. Experiments or finite element results verify teeth wear and gear meshing models, and how varying wear depths affect contact force, contact pressure, mesh stiffness, and system nonlinear dynamics are studied. The results show that the generation mechanism of significant wear near the tooth tip is attributed to the pressure concentration effects induced by corner contact. Micron-level teeth wear significantly deteriorates contact pressure distribution and induces pressure concentration near the reference circle. Moreover, the teeth wear will reduce the number of mesh teeth and cause the system’s chaotic motion and motion-jumping phenomenon. This work enhances the gear wear model’s calculation accuracy and explores the gear wear effect mechanism on mesh characteristics and the nonlinear response of gear systems.