High-speed rail roller bearings with built-in triboelectric sensors

To dynamically monitor roller bearings in high-speed trains and computationally predict their fluid dynamics with high precision, this study proposes a built-in, compact, and integrated triboelectric cage speed sensor for double-row tapered roller bearings (TCSS-DTRBs). The design is based on a dual-sided electrode located in the internal space and two polytetrafluoroethylene dielectric layers that rotate synchronously with both cages, forming two freestanding-mode triboelectric nanogenerators that detect motion on both cage sides. Experiments on a full-scale train roller bearing are conducted under two types of lubricating scenarios. The stability and applicability of the monitoring function are validated using two different scale test rigs. Furthermore, setting the skidding results of the TCSS as boundary conditions, a FLUENT model of the DTRB is established to achieve high-precision computational fluid dynamics predictions. The combination of TCSS and fluid dynamics analysis provides a solid foundation for the intelligent design of train roller bearings.