Intelligent Thrust Bearing Based on Electret Rotary Power Generator with Self-Powering and Self-Sensing Capabilities

With the rapid development of the Internet of Things (IoT) and big-data technology, the higher requirement for the intelligence of bearings has been put forward. This paper reports a novel type of intelligent thrust ball bearing, called electret thrust ball bearing (ETBB), which has both self-powering and self-sensing capabilities. Due to the common characteristics of non-contact and relative rotational movement, the electret rotary power generator on the free-standing mode is embedded into the thrust ball bearing, which not only maintains the mechanical structural integrity of the thrust ball bearing, but also obtains the capabilities of self-powering and self-sensing. A localized selective corona charging method is developed for integrating both positive and negative charged electret into the rotor of the ETBB to improve output performance and the output power of the ETBB by bipolar charging is increased by 365% to 0.35mW. Through measuring the electrical output characteristics of the ETBB at different rotating speeds, it is found that the rotating speed of the ETBB can be characterized by the two values of output current and frequency, which has extremely high sensitivity and stability. This work proposes an electrostatic intelligent bearing with self-powering and self-sensing, which has widespread application prospects in the development of IoT and Intelligent machinery.