Research on the Instantaneous Slip Ratio Monitoring of Rolling Bearing Based on Variable Reluctance Sensor

The bearing slip ratio is an effective index for bearing slip evaluation, and is also of great significance for bearing design and condition monitoring. In this paper, we proposed a slip monitoring method based on the variable reluctance sensor (VRS). A magnetoelectric probe is directly aligned with the outer ring to obtain the instantaneous rotation frequency of the inner ring, cage rotation frequency, and rolling element revolution frequency. In addition, a method based on frequency-shifting filter and spectrum correction (FSF-SC) is used to evaluate the instantaneous slip ratio, and a test rig was developed to verify the effectiveness of the proposed method under different speeds, workloads, and oil levels. Experimental results show that the slip ratio measured by the proposed method is very close to that measured by ultrasonic, and the deviation is only 0.02%. Moreover, the proposed instantaneous slip ratio is useful for bearing condition monitoring.