Characterization of Acoustic Emissions from Journal Bearings for Fault Detection

Acoustic emission (AE) technology is one of the most established diagnostic techniques for
rolling bearing monitoring in rotating machinery. The application of high-frequency AE for
bearing diagnosis is gaining acceptance as a useful complimentary tool. This paper demonstrates
the use of AE measurements to investigate the AE characteristics of self-aligning journal bearings
under different rotational speed, radial load and lubrication condition. To undertake this task, a
purpose-built test rig was employed for collecting AE signals from the journal bearings. Then, the
collected data was processed using time domain and frequency domain analysis methods which
are of the most common techniques used for monitoring in AE applications. The results shown
that the data analysis method applied in this work is effective for characterising complicated AE
signals. Based on obtained results, it is concluded that the AE energy levels in high frequency
range higher for the higher radial load and speed condition. For different lubricant cases AE
energy becomes high when the viscosity is lower, which means that AE can be used to detect
lubrication degradation in journal bearings.