Influence of the Sun Gear on the Dynamical Behavior of Planetary Gear Train

A lumped-parameter model of a single-stage planetary gear train was established. The influence of the rotary inertia of the sun gear on the dynamical behavior of planetary gear train was investigated. The steady responses were obtained by using numerical method. The characteristic of the system was described by time history, phase plane plot, Poincare section and FFT spectrum. The result shown clearly that the rotary inertia of the sun gear had a very significant influence on the dynamic behaviour of planetary gear train. The response of the system experienced the period motion to the doubling period motions, the doubling period motions to the period-4 motion, and chaos motions at last, under the changing of the rotary inertia of the sun gear. It provided necessary theoretical base to improve the design of the planetary gear train with favourable dynamic behaviour.