Motor bearing voltage simulator and bearing electric corrosion test system

The bearing current can lead to electric corrosion damage in bearings, thereby reducing the reliability of motor. Currently, the mechanism of bearing electric corrosion damage is not well understood. The traditional motor test platforms have limitations such as difficulty in measuring bearing currents, and inability to perform accelerated electric corrosion experiments. Therefore, a bearing voltage simulator and a bearing electric corrosion test system were proposed. First, the circuit structure, working principle, and parameter design method of the simulator were presented. Then, the structure and design method of the test system were proposed, including methods for applying electrical and mechanical stresses. Furthermore, the simulator prototype and the test system were designed. The bearing voltage and bearing current output from the simulator were compared with those from the actual motor. Finally, a 6208 bearing used in an automotive motor was chosen as the experimental subject, and a 360-hour bearing electric corrosion experiment was carried out using the time-truncation method. The experimental results show that the simulator can fully simulate the bearing voltage and bearing current of an actual motor. The bearing damage characteristics obtained from the electric corrosion experiment are consistent with typical electric corrosion damage in motor bearings, thus verifying effectiveness of the simulator and test system. The system can be used for research on bearing electric corrosion damage and failure mechanisms.