Diagnostics of rolling bearing defects using envelope spectrum analysis of vibration and acoustic signals

The method of spectral analysis of the envelope of high-frequency vibration signal components is used to identify defects and assess the condition of rolling bearings. The disadvantage of this approach is the high loss of useful signal as the vibration transducer moves away from the product being diagnosed. The paper presents the results of the diagnosis of rolling bearing defects using the analysis of the envelope spectrum of the acoustic pressure signal obtained using measuring microphones. The vibration and acoustic radiation of a serviceable support bearing and a bearing with a defect artificially applied to its inner race were analyzed. It is shown that the identification of rolling bearing defects by acoustic pressure signals has limitations due to the fact that sound reflection, background noise and interference can mask useful signals. The presence of random spatial noise leads to a low signal-to-noise ratio, however, microphones located close to the damaged bearing make it possible to determine the presence of a defect and its type. The obtained results can be used to improve the methods of diagnostics and monitoring of the technical condition of rolling bearings.