Efficiency Analysis of Planetary Gear Train under Ring Gear Deformation

摘要

Transmission efficiency is a key parameter of planetary gear train, it has a significant effect on power density of transmission systems. Usually, ring gear is regard as a rigid part in the efficiency calculation of planetary gear train. However, most of the planetary gear train adopt flexible ring gear design, which means the deformation of ring gear is large. In addition, the deformation of the ring gear leads to the change of the meshing relationship of the gears in the planetary gear train, thus both the dynamic load, sliding speed and friction force in the planetary gear train are affected. Besides, the meshing power loss in planetary gear train is also changed. Therefore, this paper takes the elastic deformation of the flexible ring gear and the dynamic friction force along the contact path of the gear teeth into consideration. Then the vibration responses of the planetary gear train are calculated based on a new established concentrated mass dynamic model. Next, power loss on the meshing interface and the meshing efficiency of the planetary gear trains are evaluated with the consideration of ring gear deformation. The calculation results show that the elastic deformation of the ring gear has a great influence on the meshing efficiency of the planetary gear train.