The mapping relationship between multi-source errors and lost motion in planetary gear train

As a key indicator for evaluating the kinematic accuracy of planetary gear train (PGT), lost motion is affected by multi-source errors coupled of geometric and structural errors and their probability distribution characteristics. A thorough understanding on the mapping relationship between multi-source errors and lost motion is crucial to the improvement of kinematic accuracy. With this idea, this paper establishes a kinematic model of PGT considering multi-source errors. In this model, the structural error is derived based on the time-varying meshing stiffness affected via both geometric errors and load distribution on different power branch. Meanwhile, the uncertainty of geometric errors is incorporated into the PGT kinematic model to ensure the accuracy of the mapping relationship between errors and lost motion. Based on this kinematic model, the impact of multi-source errors on lost motion is revealed. The results indicate that the kinematic accuracy of PGT can be improved through simultaneously optimizing the errors of sun gear and any component. Also, the compound effect of carrier and ring gear errors constitutes the primary cause for the decrease of kinematic accuracy.