A novel self-powering planetary gear bearing skidding sensor using dual triboelectric nanogenerators

Wind turbines, positioned as advanced devices with significant potential for optimizing the global energy landscape, have garnered widespread attention. Among the integral components of a wind turbine, the planetary gearbox (PGB) plays a crucial role. Real-time monitoring of the PGB holds immense promise for enhancing its service life and quality. The main objective of this study is to design a novel type self-powering planetary gear sensor of PGB that can measure the speed of PGB system and monitor the skidding state of planetary gear bearings in real-time under stationary and non-stationary conditions. The planetary gear speed and bearing skidding sensors are introduced by dual triboelectric nanogenerators (PBSS), comprised of two sets of concentric floating freestanding layer mode triboelectric nanogenerators (TENGs) designed for the planetary gear (G-TENG) and its bearing cage (C-TENG). The assembly ensures the structural integrity and original functionality of the PGB. The study investigates the impact of rotational speed, composite dielectric material, internal clearance on optimizing the output of the PBSS. The speed sensing function on PGB system and planetary bearing cage of PBSS has been rigorously validated by commercial sensors. Results from self-sensing tests reveal that the featured frequency of triboelectric signal accurately quantifies the speed of G-TENG, while its amplitude effectively qualifies it. C-TENG proves capable of perceiving the overall skidding and transient cage stability of the planetary gear bearing under variable speeds and torque loads. Furthermore, the superiority of the PBSS over traditional sensors in precise speed sensing under non-stationary conditions is verified.