120 Rotor Vibration Diagnosis using Wavelet Analysis : Detection of Rubbing and Lack of Lubricant in Bearings

Abstract

To diagnose unsteady rotor vibration, we developed a diagnosis method using vibration repetition factor calculated from a result of wavelet analysis. To improve the sensitivity of diagnosis, we subtracted normal vibration repetition factor from measured one. The diagnosis method detected abnormal vibrations with high sensitivity. An unsteady natural frequency vibration occurred with rubbing the rotor. As lubricant in bearings is reduced, a steady natural frequency vibration occurred, and it changed to an unsteady low frequency vibration. A steady high frequency vibration occurred when the lubricant in bearings is absent completely.