Method for Detecting Semi-solid Lubricating Grease Content by Plate Capacitance Sensor Based on Differential Technology

In order to detect the grease content of greasy semi-solid in gearbox, a method of changing the value of the plate capacitance due to the change of grease content is adopted. This paper makes a theoretical analysis of the flat capacitance sensor, carries out COMSOL simulation experiment on the detection of grease content in the gearbox by the flat capacitance sensor, studies the influence of the structural parameters of the flat capacitance sensor, the grease in the gearbox and the environment in the gearbox on the detection of flat capacitance. As a result, a flat capacitive sensor and detection circuit for detecting the grease content in the gearbox are designed. Combined with theory, simulation and practice, the algorithm of the detection system is optimized. Through the experimental verification of the grease height in the gearbox, the experimental data in the range of 0mm similar to 50mm are analyzed. The results show that the detection method works stably, has linear output, and can accurately measure the content of grease in the gearbox.