The objective of this study is to capture and characterize the acoustic emissions of radial ball bearings in operation. A comparison is made between healthy bearings and defective ones. A precise 0.012” wide groove was cut into either a ball, the inner or outer race of test bearings. To reduce vibrational interference, the test shaft is isolated using a magnetic coupling and is supported by a thrust air bearing. The test bearing is acoustically insulated from its surrounding with mass loaded vinyl and acoustic reflections are dampened by wedge foam to improve the signal quality. The acoustic emissions are captured and digitized using a smartphone. Various signal processing techniques are used to characterize the signals and analyze defect modes. The results provide a comparison between the acoustic emissions of healthy and defective bearings operated at various speeds and provide methods for characterization.

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