Dynamic modelling of the gear system under non-stationary conditions using the iterative convergence of the tooth mesh stiffness

Abstract

This paper presents a new gear dynamic model for the transmission system under the non-stationary condition with the consideration of the coupling between the external load and the internal gear excitation. The gear mesh stiffness variation is found to be the main internal excitation and therefore, the effect of the varying external load on the gear mesh stiffness is evaluated firstly, which can then be incorporated into the gear dynamic model. When the gearbox is subjected to a wide range of external load, the mesh stiffness varies correspondingly and an iterative process is proposed to ensure the convergence of the gear dynamic simulation at each step. The dynamic responses from the model with and without the iterative process have been compared. It indicates that the proposed model can successfully incorporate the external-internal coupling effect in gearbox and further shows that the operating condition has a significant influence on the gear response. The proposed model can provide an effective tool to improve the accuracy of gear dynamic modelling and improve the accuracy of gear fault diagnostics under non-stationary conditions.