A Tapered Rolling Bearing Based on Tribovoltaic Effect for Active Rotational Speed Sensing

Abstract

The issue of status sensing in bearings is a fundamental and significant subject in development of smart manufacturing. The tribovoltaic effect is a newly proposed physical effect where direct current is generated at semiconductor interfaces by friction, which is expected to provide an effective solution for intelligent bearing sensing. Herein, we firstly present a rolling mode tribovoltaic nanogenerator (TVNG) based on a steel roller and a monocrystalline silicon ingot, which has a peak current density of 3.75 A·m^-2 and an open-circuit voltage of 5.8 mV. Based on the TVNG in freestanding-mode, a tribovoltaic bearing (TVB) was fabricated consisting of two different dopped silicon rings, bearing rollers and retaining frame. The Isc of TVB has a segmented linear relationship with the rotational speed (R²=0.9933 at 400-800 rpm; R²=0.9867 at 800-1000 rpm). Furthermore, the TVB and signal processing unit are encapsulated together as mechatronic smart bearing, which can realize accurate monitoring of rotational speed for overspeed alarming. This work achieves the integration of TVNGs and bearings in terms of structure and function, providing experimental and technical support for self-sensing in intelligent components and smart manufacturing.