Fault Detection Method on a Compressor Rotor Using the Phase Variation of the Vibration Signal

The aim of this work is the application of the phase variation in vibration signal for fault detection on rotating machines in the non stationary cases. The vibration signal from the machine is modulated in amplitude and phase around a carrier frequency. The modulating signal in phase is determined after the Hilbert transform and is used, with the Fast Fourier Transform, to extract the harmonics spectrum in phase. This method is first validated on a simulator of vibration, then it is used for detecting potential faults on a rotor of a centrifugal compressor. In the case study of the centrifugal compressor, the nature of the defect was not revealed by the spectral analysis of amplitude of the non stationary vibration signal, unlike with the proposed method.