Triboelectric pad journal bearing for self-powered condition monitoring

With the widespread application of the Internet of Things (IoT) technology, smart fault detection and condition monitoring are urgently required in mechanical systems. The emergence of triboelectric nanogenerators (TENG) provides a novel strategy to achieve self-powered sensing, which can serve as an ideal candidate for the condition monitoring of bearings. In this study, a triboelectric pad journal bearing (T-PJB) was designed and fabricated to directly monitor the bearing condition. Through simulation, the geometrical structure of the T-PJB for high output was optimized, and the electrical performance was examined under various rotating conditions. The speed of the bearing shaft could be accurately measured using time-and frequency-domain methods. During the operation, faults caused by unbalanced forces were effectively identified based on the characteristics of the electrical output signals. Furthermore, the proposed T-PJB can be applied to monitor lubrication states because of its sensitive response to different lubrication conditions. Condition monitoring using the proposed T-PJB greatly contributes to reduced maintenance costs and long-term stable operation of various sliding bearings. Furthermore, the demonstrated smart T-PJB has promising feasibility in industrial applications for rotating machinery, establishing the foundation for smart plants.