Diagnosis of gear damage based on coefficient of variation method by analyzing vibration accelerations on one gear tooth

Abstract

Since minor gear damage may cause serious failures of the entire equipment, early detection of gear damage is one of the important measures to prevent the machine system from malfunction. This paper proposes a method of diagnosing early gear damage by analyzing the vibration accelerations of one gear tooth. Gears manufactured with three different kinds of methods are tested in this study. Their tooth profile error is different from each other. Therefore, the influence of tooth profile error to the damage diagnosis is also discussed in this study. The vibration acceleration on the gear box was acquired as the original signal. In order to eliminate the interference components from the original signal, the time synchronous averaging method is adopted to process the original signal. Thus, the time synchronous averaging signal of driving gear is obtained as the analytical signal. Because the abnormal wave is not obvious in the whole signal, the vibration accelerations of one gear tooth was extracted from the time synchronous averaging signal for studying in detail. For illustrating the representative character of the vibration signal, statistical parameters are calculated from the vibration acceleration of one gear tooth to evaluate the conditions of gear tooth. In addition, the coefficient of variation method is employed to evaluate the contribution ratio of these parameters to gear damage and the weight coefficient of each parameter is obtained. The statistical parameters are synthesized into a unified feature based on the weight coefficient. The results show that the unified feature distance of damaged tooth is distinctive from the normal teeth, and the gear damage can be detected by the present method in this study.

Gear tooth surface damage diagnosis based on analyzing the vibration signal of an individual gear tooth

“…Because vibration signal is usually affected by environmental noise or vibration of other components, the abnormal features of gear damage are not clear in the original signal, especially when the gear damage is small. 2 In addition, because many gears work at the same time, it is beneficial to study the signal of some specific gears in order to precisely locate the gear damage. The time synchronous averaging (TSA) technology has advantages of reducing noise and extracting the signal of the target object.…”