Fault diagnosis of low-speed bearing with acoustic emission technique


Roller element bearings are widely used in both domestic and industrial applications. They play a major role in rotating machinery, and their failure can require machine shut down. Hence, research into improving the condition monitoring of these bearings is ongoing. Today, the major problem related to condition monitoring of bearings is to detect faults in their early stages. Previous researchers tended to focus on monitoring the bearings in high-speed machinery with only limited research on monitoring the condition of low-speed bearings. However, many applications are in the low speed range and this study investigates the applicability of Acoustic Emission (AE) to the detection of the preliminary stages of bearing defects at low speeds (10- 100 RPM). The defined tasks are to detect incipient faults at the bearing outer race at the earliest possible stage, and to investigate the effects of operating variables such as speed and load using statistical analysis of the AE signal. The results of this investigation show that AE successfully detected the seeded defect on the bearing outer race under low speed applications. Also, it is concluded that rotational speed has a strong influence on the measured AE parameters but that they are entirely independent of the load.