Influence of manufacturing errors on dynamic floating characteristics for herringbone planetary gears

Owing to the present of manufacturing errors, the dynamic floating characteristics of herringbone planetary gear train (HPGT) can be changed in comparison with the original ideal design. In this research, based on the actual structure of herringbone gears, taking into consideration manufacturing eccentric errors and tooth profile errors, bearing deformation, time-varying meshing stiffness, gyroscopic effect, and so on, a novel and generalized bending–torsional–axial coupled dynamic model of a herringbone planetary gear train is presented to investigate the dynamic floating performances applying the lumped-parameter approach. The model is capable of being employed for the vibration behavior analysis of the HPGT with different types of manufacturing errors and arbitrary number of planets. The variable step Runge–Kutta algorithm is utilized to compute the dynamic responses of the HPGT system. In combination with the proposed computational approach of the component floating displacement amount, the relationship among manufacturing errors, component floating displacements, and different floating forms is obtained, and the effects of manufacturing errors on the HPGT dynamic floating performances are discussed. Meanwhile, sun gear radial floating trajectories in two cases of sun gear float and non-float are compared and analyzed. Results indicate that the manufacturing error and component float prominently affect the dynamic floating characteristics in the HPGT system.