Effective and Simple Identification Indicators of Different Rolling Bearing Fault Types

The paper presents some effective frequency indicators of rolling bearing faults. These indicators are used to diagnose localized faults in rolling bearing elements. These faults usually cause strong frequency peaks with harmonics in the envelope spectrum of the vibration signal. In the paper, we proposed a new type of indicator and compared it with the often used the log ratio of fault amplitudes. This relative value of characteristic fault frequencies works very effectively in the case of only one type of faults. In the case of simultaneous occurrence of several faults, this indicator often fails. We proposed a robust frequency indicator that correctly detects characteristic fault frequencies in such a situation. The conducted experiment in which we simulated the inner and outer faults race of a rolling bearing confirmed the effectiveness of the proposed indicator and its better identification properties in relation to the used logarithmic amplitude factor.