Novel rolling bearing diagnosis technology using spectral kurtosis and the wavelet higher-order spectra

A novel technology based on a combination of spectral kurtosis and the wavelet higher-order spectra for the detection of local fatigue defects in rolling bearings by vibration measurement is studied. The bearing test-rig has a coupled motor driving a shaft supported on three identical rolling bearings. The drive provides a 20-60 Hz supply frequency. Tests were conducted at a full-speed and full-load condition. The full-speed and full-load condition corresponds to a 60 Hz supply frequency and 196 N resultant radial load. The test bearing was placed on the non-drive end. A systematic methodology for the selection of parameters of the wavelet higher order spectra is developed and successfully validated experimentally. Experimental validation of the technology is performed using test-rig data related to undamaged bearings and bearings at an early stage of local fatigue damage. The high effectiveness of early bearing diagnostics by the proposed technology has been experimentally demonstrated using the Fisher criterion and impact detection rate. The mean Fisher criterion and the impact detection rate for all impacts is 5.8% and 98%, respectively.