Fault mechanism and dynamic modeling of planetary gear with gear wear

Gear wear is a typical and common early failure, which could lead to geometric deviation of tooth surface, further affecting vibration signal and transmission error. This paper is devoted to analyzing fault mechanism and dynamic characteristics of gear wear, which provides the basis for vibration-based fault diagnosis and monitoring of gear wear. For this purpose, a purely torsional dynamic model of planetary gear with gear wear is proposed where gear wear is evaluated by Archard's equation and it is incorporated into the dynamic model through time-varying mesh stiffness, unloaded static transmission error and gear backlash. Inspired by the work of Chen et al., gear wear is viewed as a kind of tooth deviation and the influence of gear wear on planetary gear dynamic parameters can be analyzed. Finally, the vibration responses of planetary gear under the effect of gear wear are analyzed.