Abstract: The key issue is how substituting plastic gears for steel ones affects planetary gear dynamic behavior. A torsional dynamic model of planetary gears is presented with time-varying meshing stiffness, damping, error excitation and gear compliance considered. The vibration teat rig for planetary geared system is also constructed. The dynamic behavior of the planetary geared systems composed of S(steel)/N(plastic)/S(steel), SSS, SSN and NSS (sun/planet/ring gear) are investigated. Numerical and experimental results demonstrate that plastic gears can dramatically change the dynamic behavior of planetary geared systems. The numerical results on the planetary geared system indicate that plastic gears can reduce dynamic loads on sun-planet and ring-planet gear mesh markedly. The experimental results also show that substituting plastic gears for steel ones can effectively reduce the high and low frequency vibrations for planetary geared systems.

Key words: Compound mode, Dynamic behavior, Planetary gear, Plastic gear