Dynamic modeling and analysis of planetary gear train system considering structural flexibility and dynamic multi-teeth mesh process

The structural flexibility of planetary gear trains (PGTs) is a significant factor that affects tooth loads and system vibrations, especially in heavy-duty wind turbine gearboxes. Therefore, it is crucial to investigate the influence mechanisms of complex structural deformations on tooth loads and system vibrations. In this work, a dynamic modeling approach is proposed for the complex carrier and ring gear based on the condensation theory of finite elements. The dynamic model of the sun shaft is modeled using the Euler-Bernoulli beam element, and the planetary gear set is modeled using the lumped parameter method. Then, the dynamic multi-teeth mesh process is developed using variable-speed characterization variables and virtual vibration line displacements. Lastly, the rigid-flexible coupling dynamic model of PGT is established and validated. The results indicate that treating components as rigid solids may lead to an underestimation of the impact of input torque variation on system vibrations. When the input torque remains stable, the tooth stiffness can be used to assess the overall change trend of tooth loads. However, when the input torque varies significantly, it is necessary to take into account the comprehensive structural deformations.