Bearing fault detection and fault size estimation using an integrated PVDF transducer

Vibration analysis of bearings by accelerometer sensors is one of the most common techniques in bearing condition monitoring. However, the susceptibility of accelerometers to noise and vibration of other machines creates practical difficulties in detecting bearings faults in applications with noisy settings. To overcome this issue, the development of integrated sensors in bearings with a short transmission path has been an emerging research area to enhance fault detection in bearings. According to the literature, polymer-based piezoelectric transducers can be a proper transducer for this application, although their performance has not been thoroughly investigated. Therefore, in this research, using an integrated PVDF transducer in a cylindrical roller bearing is proposed to detect the local fault and estimate the size of the damage. Through experimental analysis in a bearing test system, the performance of the PVDF is evaluated. According to the results, the fault symptoms can be accurately captured in the voltage signal of the PVDF transducer under constant and variable rotational speeds. Also, by analyzing the behavior of a roller over a local fault and comparing it with the measured voltage signal, the fault size estimation with an accuracy of ±0.025 mm is achieved.