Supported by Natural Science and Engineering Research Council of Canada (Grant No. RGPIN-2015-04897), International S&T Cooperation Program of China (Grant No. 2015DFA71400), National Key Research and Development Program of China (Grant No. 2016YFB1200401), and National Natural Science Foundation of China (Grant No. 51375078, 51505066).
Tooth pitting is a common failure mode of a gearbox. Many researchers investigated dynamic properties of a gearbox with localized pitting damage on a single gear tooth. The dynamic properties of a gearbox with pitting distributed over multiple teeth have rarely been investigated. In this paper, gear tooth pitting propagation to neighboring teeth is modeled and investigated for a pair of spur gears. Tooth pitting propagation effect on time-varying mesh stiffness, gearbox dynamics and vibration characteristics is studied and then fault symptoms are revealed. In addition, the influence of gear mesh damping and environmental noise on gearbox vibration properties is investigated. In the end, 114 statistical features are tested to estimate tooth pitting growth. Statistical features that are insensitive to gear mesh damping and environmental noise are recommended.