Transmission Error in Planetary Gear Systems as an Excitation Source Influencing Vibration Response and Wear Mechanisms

Abstract

Planetary gear systems offer compact design and high-power density, but they are strongly influenced by transmission error (TE), which originates from geometric deviations and elastic deflections. This study presents a dynamic model that integrates elastic compliance, mesh stiffness, damping, and error excitation to evaluate coupled gear responses. Numerical results show that planet–ring contacts undergo larger forces and deflections than sun–planet meshes. Time–frequency analysis with continuous wavelet transform (CWT) reveals nonstationary vibration patterns, while gear tooth flank inspection confirms torque bias and micro-pitting. The findings connect modeling predictions with observed wear, offering insights for planetary gear diagnostics and design.