Dynamic modeling and analysis of high-speed flexible planetary gear transmission systems

Abstract

Modern planetary gear transmissions are often made with flexible components and operated at high or varying speed. Despite advances in understanding their dynamic performance, they remain vulnerable to problems leading—in some cases—to subsequent system failure. In this study, using angular and translational displacements as generalized coordinates, we establish lumped-parameter dynamic sub-models of the sun and planet gears that accurately consider gear-tooth dynamic behavior; we also develop reduced-order finite-element sub-models that fully consider the flexibility of the housing and carrier. Investigating the coupling between these sub-models in depth enables us to construct a complete hybrid dynamic model that can be used for coupling-dynamics analysis of flexible planetary gears under high- and variable-speed conditions. The accuracy of our planetary-gear-dynamics model is verified by comparing simulation data in the time and frequency domains to the results of experiments conducted on a planetary gear transmission system test bench specially built for this purpose. Finally, the dynamic characteristics of high-speed flexible planetary gears are studied at low speed, high speed, and high acceleration.