Dual-impulse behavior analysis and quantitative diagnosis of the raceway fault of rolling bearing

The dual-impulse behavior of rolling element bearing (REB) can estimate the degree of spalling damage effectively, which is of great significance to damage assessment, quantitative fault diagnosis and life prediction. However, the existing methods can not accurately extract the time point of the roller roll-in or roll-out fault. Hence, A nonlinear dynamic model of rolling element bearing is established for quantitative diagnosis of REB in this study, which introduces the outer race and inner race faults containing different sizes. The relationship between vibration response and fault size was observed by simulated signals. By comparing the simulation signal with the theoretical time of the rolling element passing through the fault area, and introducing the contact force variation of the rolling element during the process, the vibration characteristics of rolling elements roll-in and roll-out the fault are analyzed and the corresponding point in the vibration signal is found accurately. When the fault size is small, the vibration signal attenuates locally after the corresponding second step impact, and then continues to increase to reach the second peak value. With the increase of fault size, the phenomenon of dual-impulse is gradually obvious. Vibration signals of REB test rig are measured according to different raceway fault sizes. The experimental results agree well with the simulation results.