Dynamic modeling and analysis considering friction-wear coupling of gear system

Gear wear becomes one of the important reasons for the fault of gear systems by causing tooth surface geometric deviations, changing time-varying mesh stiffness (TVMS), and increasing unloaded static transmission error (USTE). However, existing wear prediction models ignore the effects of friction and tooth profile parameter updates, which inevitably leads to unclear research on dynamic analysis. Based on the Archard equation, this work proposes a real-time iterative update model to calculate the wear evolution process with equivalent curvature radius updates. Subsequently, an improved friction-wear coupling model is developed to calculate the wear depth, TVMS, and USTE, with an iterative solution process based on the updating of friction and wear coefficients, and the load sharing factor (LSF). The effectiveness of the improved model is verified by wear experiments and finite element analysis. Based on the tribo-dynamic model of the gear-rotor-bearing systems, the dynamic characteristics considering friction-wear coupling are studied. The results indicate that the effect of friction intensifies as the speed decreases, while increased wear amplifies vibrations at most speeds, exacerbates meshing shocks, and initially expands then contracts the chaotic speed range. This work provides strong theoretical support for predicting wear depth and understanding gear wear behavior.