Dynamic Modelling of a Two-stage Helical Gearbox with the Consideration of Nonlinear Rolling Bearing Contact and Time-varying Meshing Stiffness

Gearbox system is a vital part in the industry and our daily lives, of which the dynamic behavior is important for equipment's prognostics and health management. In this paper, considering the effects of time-varying stiffness and nonlinear characteristics of bearings, one dynamic model of a two-stage gearbox test rig with helical gears is established, in which the motion of housing is included. An efficient expression of time- varying meshing stiffness has been adopted to study the gear dynamics, with the model of helical gear pair derived from the one of spur gear pair. Based on the coupling gear-rotor-bearing dynamic model, steady-state vibration response of the gearbox has been obtained by using numerical methods, and the vibrations of the input and output positions are compared and analyzed. The results prove that the position where the sensor is placed has an effect on the signal detection, and the effect of time-varying meshing stiffness on system response is discussed.