Rolling Bearing Fault Diagnosis Based on the Coherent Demodulation Model

The rolling bearing is an important part of rotary machineries and the health state monitoring is currently a hot research topic. There are four typical failure modes of a rolling bearing: the inner race failure, the outer race failure, the rolling element failure and the support frame failure. Based on the principle of the coherent demodulation, a new method for rolling bearing fault diagnosis is proposed in this work. This method establishes a coherent demodulator simulation model which is usually adopted in the field of radio communications. The proposed method first demodulates the vibration signal with coherent demodulation principle. Then, the characteristic frequencies related the different failures modes are extracted to obtain the fault characteristic amplitudes, to diagnose the ongoing failure mode. The bearing fault data from the Case Western Reserve University Bearing Test Center is taken as an example to verify and analyze the effectiveness of the proposed method. The results show that this method can accurately diagnose the corresponding failure mode with different locations and sizes.