Speed Monitoring and Fault Detection in Bearings Using an Embedded Piezoelectric Transducer Under Speed Varying Condition

For more than three decades, vibration monitoring by accelerometers has been a common technique in the health monitoring of bearings and rotating machines. These sensors are typically mounted on the housing of the system to collect the vibration data. However, the susceptibility of accelerometers to surrounding noise and vibration has attracted more attention toward embedded sensors in bearings. Also, the current trend toward intelligent manufacturing and IoT requires mechanical components with integrated sensors to monitor their health status. In this research, a previously developed piezoelectric transducer embedded in a bearing housing is further investigated for condition monitoring of bearings. By using this transducer, the rotational speed of the bearing in the variable speed condition is measured. The results show a great correlation between the estimated speed compared with an encoder. Moreover, the performance of the transducer in local fault detection in the speed-varying condition is investigated. According to the results, it can be concluded that this low-cost and self-sensing transducer can be successfully used for condition monitoring and speed measurement in bearings.