Detection of surface defects in a bearing ball using electromagnetic flux

Ellen M. Bradley, David Carl Swanson

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations


The electromagnetic flux of rotating ball bearings was measured by a gradiometer-configured inductance coil. Ball spin, and drive and slave ring frequencies are distinguishable throughout testing. One ball was tested for 22 hours, 45 minutes without reaching the failure level and the second involved restarting a ball that had already reached the failure level, but showed minimal visible damage. The first test showed increased magnetization of the ball via an increase in flux at the ball spin frequency by 14 dB. The second test shows a consistent level of flux at the spin frequency compared to the final level detected in the first test. As the surface of the ball becomes damaged from skidding, an increase in the magnetic field is hypothesized to originate from the abrased ferrous surfaces. The spinning ball allows this feature to be easily detected by a simple coil of wire.

Original languageEnglish (US)
Pages (from-to)537-542
Number of pages6
JournalProceedings - National Conference on Noise Control Engineering
StatePublished - Dec 1 1997
EventProceedings of the 1997 National Conference on Noise Control Engineering , NOISE-CON. Part 2 (of 2) - University Park, PA, USA
Duration: Jun 15 1997Jun 17 1997

All Science Journal Classification (ASJC) codes

  • Acoustics and Ultrasonics


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