Relationship between Planet Gear Parameters and the Vibration Characteristics of Planetary Gearboxes

The simultaneous engagement of planet gears with the sun gear and the ring gear is the main reason for the complicated vibration of the planetary gearbox. However, the relationship of planet gear parameters on the vibration has not been effectively revealed. To end this, the modified meshing phase model of gear pairs is established, and moments of sudden stiffness changes of gear pairs are calculated. Furthermore, the problem of simultaneous tooth shifting of gear pairs and the number of sudden stiffness changes in one meshing period are also discussed. Then, according to this sudden changing number, planetary gearboxes without tooth displacement are classified into four types, where the classification results are closely related to the gear number and the teeth number of the planet gear. Finally, the dynamic simulations of these four types of gearboxes are carried out in the finite element software. Simulation results show that these 4 vibration signals are different both in the time and frequency domains.