Model-based condition index for tracking gear wear and fatigue damage

This paper describes a method that utilizes linear dynamic modeling to track the development of gear wear and tooth fatigue crack. A model is created from the gear meshing vibration signal when the gear is new and then the model is applied to vibration data taken over the gear's lifetime to calculate the prediction error. This error is expected to increase over the lifetime as the evolvement of the faults alters meshing stiffness. The method is evaluated by experimental data collected in two tests where gear wear and gear tooth fatigue cracks grew over time. It was found that the method gave more consistent trend when compared with state-of-the-art.