Research on Vibration Diagnosis Method of Broken Tooth Failure for Marine High-Speed Gearbox

Complex and changeable working conditions of marine high-speed gearbox make its operating environment harsh and cause the risk of internal gear tooth failure. In order to monitor the running status of high-speed gearbox and diagnose fault categories, vibration mechanism of high-speed gear box was analyzed and FE model of high-speed gearbox was established, then vibration response of the normal state of the body surface was simulated. Through testing actual vibration of the gearbox surface, correctness of the model and calculation method was verified. Based on the above analysis, exciting forces and vibration response of broken tooth failure were simulated, and then comparing root mean square value, kurtosis and peak in time domain vibration features of broken tooth with normal tooth, the rules of variation were summarized. On the other hand, contrast to normal and failure states of tooth, it was found that amplitudes of the rotation frequency and its higher order frequency, engagement frequency and sideband frequency with rotating frequency as modulation frequency were changed regularly by ways of frequency domain and Zoom-FFT analysis. Study shows that the vibration analysis method can identify broken tooth failure of marine high-speed gearbox.