Diagnosis of rolling bearing by measuring time interval of AE generation

We have developed a new method for measuring time intervals of Acoustic Emi ssion (AE) generation for diagnosis of a radial rolling bearing The method makes the AE signal itself a trigger of the oscillation of the clock pulse and measures the time interval of AE generation by integration of the clock pulses. The measurement device consists of the threshold, clock, time inte rval measurement and memory circuit, and was applied to rolling contact fat igue experiments. It was confirmed by the experiments that the measured tim e intervals of AE generation on the inner raceway or the ball agreed with t he value calculated based on the kinetics of the rolling bearing. Moreover we could identify the elements in which a fatigue crack was propagating by the method before the spalling appeared. The identified elements agreed wit h the failed elements.