A coupling dynamics analysis method for a multistage planetary gear system

The lumped parameter and finite element methods (FEM) are two relatively common modeling approaches for the coupling vibration analysis of the planetary gear system. In order to overcome the lack of fidelity of the lumped parameter models and the high computational cost of finite element models, and in order to obtain accurate vibration response predictions to understand the coupling vibration mechanism in the planetary gear system, a comprehensive, fully coupled, dynamic modeling method is proposed by applying a virtual equivalent shaft element. The continuous planetary gear transmission system is divided into numerous shafting elements. The dynamic model of the planetary gear system is constructed applying these shafting elements, including the shaft segments and flexible ring gear, and as well as the flexible planet carrier. The proposed method is implemented on a two-stage planetary gear system, and it is verified by comparing the results to the calculations using existing lumped parameter and FEM. The quasi-static and dynamic modeling results are presented to study the dynamic behavior and coupling characteristics in-depth. The proposed method can be used to guide the design of high reliability and low vibration planetary gear systems.