A specially-designed electrostatic sensor for the condition monitoring of rolling bearings

The electrostatic method is a rapidly growing research field in the monitoring of rotating equipment. This article reports how a specially-designed integrated electrostatic sensor was utilized to monitor the working conditions of rolling bearings. We firstly analyzed the principle and mathematic modeling of inner current noise generated by cable vibration and deformation. To ensure the electrostatic monitoring avoided being affected by cable vibration and deformation, we designed a ring-shaped printed circuit board to integrate the electrostatic electrode and condition unit together, which can be mounted tightly beside the rolling bearings; in this way, the cable connecting the electrode with the condition unit is removed and the distance between the electrode and rollers is shortened. Experiments using this integrated sensor board were conducted to obtain the electrostatic signals of working bearings. Time features were analyzed in detail to show the differences of four working bearings across the whole process. Experimental results show that the proposed integrated electrostatic sensor has a good performance in the electrostatic monitoring of rolling bearings.