Abstract:Planetary organizations have a wide range of applications, its stability affects production reliability. In order to study the vibration characteristics of planetary gears, the dynamic model of planetary gear mechanism was established by using the mass method, and a single gear vibration model was established to obtain the factors that affected the vibration characteristics. Using the dynamic analysis software, the vibration of the planetary gear mechanism under the impact load was obtained, and the angular velocity curves were obtained as well as the meshing force curves. The results show that the meshing force fluctuates widely in the starting stage, impact is existed, meshing force curve fluctuates up and down around the mean; in the small cycle the same movements are repeated.Under the action of impact load, the instability of meshing force increases which fluctuates in a wide range, meshing force closes to three times of stable load.After the structural flexibility, flexible body contact occurs small elastic deformation which enlarges the meshing impact deformation. The results provide reference for the optimal design of planetary gear transmission system.