In Situ Monitoring of Dynamic Loads on Shafting via Nanogenerators

Abstract Dynamic loads are inevitably generated during the operation of rotating machinery. In situ monitoring the dynamic loads is of great significance for assessing shafting health. Triboelectric nanogenerator (TENG) is sensitive to motion but not suitable for load monitoring, while piezoelectric nanogenerator (PENG) is just the opposite. Therefore, the combination of the two can complement each other. From this, a dynamic load monitoring smart bearing (DLMSB) integrated with TENG and PENG is proposed. The specially designed TENG can produce an “M‐waveform”, which can be used to extract rotation frequency and distinguish the quadrant of the rotor. Meanwhile, applying PENG to capture the load condition of the bearing, and referring to the main frequency of M‐waveform, it is convenient to obtain the dynamic loads of shafting. Furthermore, a real‐time monitoring system is developed, which can realize not only real‐time monitoring of the rotation speed and dynamic loads magnitude but also the quadrant discriminating of dynamic loads. The results have shown that the monitoring error for dynamic loads is 3 N or 5.5%, and the accuracy rate for determining the quadrant of the dynamic loads can reach 93%. This study provides a novel approach for the in situ monitoring of mechanical operating status via nanogenerators.