Bearing defect detection using time synchronous averaging (TSA) of an enveloped accelerometer signal

A method of identifying a rotating bearing defect comprising the steps of:

• measuring a vibration generated at least in part by the rotating bearing using an accelerometer to obtain a waveform signal;
• filtering the waveform signal using a bandpass filter to remove unwanted signal frequencies;
• enveloping the filtered waveform signal to obtain an enveloped low frequency time waveform;
• measuring the rotational speed of the rotating bearing;
• synchronizing the enveloped low frequency time waveform to the rotational speed of the rotating bearing in such a way to preserve the phase relationship between the tachometer pulse and bearing defect to obtain a time synchronized waveform;
• averaging the time-synchronized waveform with at least one previously stored time synchronized waveform to obtain an average time synchronized waveform (TSA);
• spectrum analyzing the TSA;
• and
• identifying an amplitude of the TSA at rotating bearing defect frequencies and their multiples.

A method for identifying defects in a rolling bearing, comprising the steps of:

• measuring a rotational speed of a rolling bearing;
• measuring a vibration generated by said rolling bearing using an accelerometer for generating an accelerometer signal,
• time synchronous averaging said accelerometer signal to remove vibration frequencies which are not in synchronism to the rotational speed of said rolling bearing:
• analyzing an averaged signal to obtain bearing defect frequencies indicative of the extent of a bearing defect.