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Acoustic emission frequency discrimination Patent #: 4738137
ApplicationNo. 201968 filed on 06/03/1988
US Classes:73/660, Rotating machinery or device73/587Acoustic emission
ExaminersPrimary: Levy, Stuart S.
Assistant: Arana, Louis
Attorney, Agent or Firm
Foreign Patent References
International ClassG01N 029/04
Foreign Application Priority Data1987-06-03 JP
AbstractAn apparatus for detecting a failure in a bearing has an acoustic emission sensor which detects acoustic emission from the bearing and outputs signals indicative of power of the acoustic emission, a bandpass filter which passes only signals in the range of from 100 kHz to 500 kHz out of the signals received from the aforementioned sensor, and a comparator which compares each of the signals in the range of from 100 kHz to 500 kHz extracted by the bandpass filter with a predetermined threshold value and outputs event signals each of which expresses that the signal from the bandpass filter exceeds the threshold value. This apparatus also has a computer which receives the event signals from the comparator, determines time intervals in which the event signals occur, totals the number of event signals for respective timer intervals, and determines whether or not the number of totaled events exceeds a predetermined threshold value to determine a failure in the bearing.