Dynamic characteristics analysis for a co-axial counter-rotating planetary gear transmission system

Based on the gear system dynamics and Lagrange equation, a coupled dynamic model of a co-axial counter-rotating epicyclic transmission (CCET) system was built with the lumped-parameter method, and the support stiffness, elastic coupling and power flow of the gear train were considered in the model. Under the action of gear pairs' run-out error, meshing-frequency error and time-varying mesh stiffness together, the time-domain dynamic characteristics including the displacement response and speed response of the CCET system were achieved with the numerical analysis method, and the load distributions were compared between an ordinary gear train and a differential gear train. The results provided a basis for dynamic performance optimization and noise and vibration study of a CCET.