Mathematical Model and Sensing Characteristics Simulation of SPES for Monitoring Wear Particle in Lubricating Oil

Heavy equipment gear transmission systems require monitoring of wear particles in lubricating oil to assess the degree of wear and predict failure. Compared to the traditional detection method, electrostatic sensor is an innovative online sensor for wear particle monitoring due to its high sensitivity and strong capability of early fault warning. This study presents a new spiral-shaped probe electrostatic sensor (SPES) and derives an analytical mathematical model of point charges on a spiral-shaped probe based on the physical model. To obtain a deeper understanding of the spiral-shaped probe, a finite element model was developed by using COMSOL software to explore the sensing characteristics and spatial static sensitivity of the spiral probe. Furthermore, experimental studies were conducted to investigate the dynamic sensitivity. The findings indicate that the sensitivity distribution of SPES is asymmetric due to the asymmetric structure of the probe. The simulation analysis and experimental studies provide a scientific basis for the design of spiral-probe sensor.