Effects of friction and stochastic load on transient characteristics of a spur gear pair

The existence of randomness in external load of geared systems is widely known. Stochastic load induces more vibration and noise than deterministic load. In this paper, a nonlinear dynamic model is developed considering time-varying mesh stiffness, backlash, sliding friction, and stochastic external load. Friction is first introduced in a spur gear pair nonlinear dynamic model under stochastic load. Monte Carlo simulation is applied to analyze the transient characteristics focusing on the effects caused by stochastic load and friction. The results show that stochastic load makes the system stay in the transient state for a longer duration and lower transient stability comparing with the results under deterministic load. In addition, the system's transient stability and responses' dispersion vary with the increase in friction coefficient. The friction coefficients that will cause the lowest transient stability and highest dispersion of relative angular displacement are identified.