Dynamic Behaviors On Coupling Effects Between Fatigue Pitting and Wear in Spur Gear Transmission System

Gear transmissions are widely used in modern mechanical products, and the unavoidable fatigue pitting and wear damages on the tooth surface will lead to the deterioration of its dynamic behaviors. Moreover, there is a complex coupling effect between fatigue pitting damage and wear damage. Therefore, it is very necessary to study the coupling effects of fatigue pitting and wear on dynamic behaviors. Based on the analysis of fatigue pitting characteristics, the probabilistic growth model of fatigue pitting damage is established, and the characteristic parameter models considering fatigue pitting damage are determined. The characteristic parameter models considering wear damage are obtained by employing an improved wear model. Furthermore, the fatigue pitting area model, the wear depth model and a comprehensive time-varying mesh stiffness (TVMS) model under fatigue pitting-wear coupling damage are developed. A novel analytical method for fatigue pitting-wear coupling damage is proposed. The mechanism of fatigue pitting-wear coupling damage is explored by an iterative analysis. The dynamic behaviors of coupling damage are investigated by the analysis of the six degree-of-freedom (DOF) spur gear transmission system. The results of the comparative analysis show that the dynamic behaviors under coupling damage are significantly enhanced over either single damage. Fatigue pitting damage plays a dominant role in the reduction of TVMS, while wear damage mainly affects the increase of unloaded static transmission error (USTE). The proposed method is a good guiding significance for dynamic monitoring and fault diagnosis of gear transmission system.