Vibro-impact characteristics of planetary gear transmission

In order to study the dynamic vibro-impact characteristics of planetary gear transmission system under the operating conditions of high speed and light load, a new planetary gear transmission modeling method is presented. In the modeling process, linear springs were used to simulate gear mesh elasticity under heavy load cases, and the Hertz contact theory was used to calculate the contact force under light load cases. In addition, the vibro-impact model of a planetary gear transmission was established by using lumped mass method. The effects of the operating conditions on the system vibro-impact characteristics are analyzed. As results show that, with the growing of the input speed, the mesh force exhibits obvious fluctuations due to the resonance of the sun gear and carrier appears torsion vibration, ring gear's transverse vibration under the heavy load. Under the light load condition, the vibro-impact occurs in the gear pair, the changing trend of the contact force shows strongly nonlinear characteristics. The time of contact loss in gear pair decreases gradually as the load is increased, until it is reach vibro-impact threshold value, then no contact loss happens. With increasing of the input speed, the time of mesh-apart is decreased gradually, and the fluctuation amplitude of contact force shows a linearly increasing trend. The study provides useful theoretical guideline to the low-noise design of planetary gear transmission.