Dynamic Model for Planetary Gear Train in a Aircraft Rotary Actuator

Abstract

The study on non-linear dynamic properties of two stage planetary gear train used in machine device with double-tooth has not been reported. This work theoretically studied the vibration model of the aircraft rotary actuator double-stage planetary gear train (Type 3K) constructed with spur gears, and used it to investigate their natural frequencies and vibration modes. The model admits three planar degrees of freedom for each of the sun, ring, carrier and planets. It includes key factors affecting planetary gear train vibration such as the time-varying mesh stiffness, integrated error of gear tooth contact, the bearing support stiffness and the other factors, and gives the vector expressions. The thesis derives the meshing pair relative displacement in the meshing line based on the analysis of planetary gear train elastic deformation, and establishes the sun, planet, carrier and ring sub-structural dynamics model by the dynamic sub-structural modeling method. For the mode, the relation between inherent frequency and vibration amplitude is investigated in detail by the dynamic characteristics analysis. In accordance with the frequencies calculated and compared with the results by using finite element method, the comparison results show that method proposed is correct.