Research on Ferromagnetic Wear Debris Sensor Based on LC Resonance

By detecting the wear debris information in the lubricating oil through lubricating oil detection technology, it is possible to achieve fault early warning and health assessment of key components of machinery equipment. The magnetic plug sensor, as a typical online detection sensor, has been widely used in the field of oil-liquid detection. This article proposes a magnetic plug-type ferromagnetic particle detection sensor based on LC resonance, which can be used to detect ferromagnetic wear debris in the oil liquid of engineering equipment. The circuit transmits the resistance signal of the detection coil to the PC end, thereby achieving the detection of ferromagnetic metal particles in the oil liquid. The sensor’s optimal frequency and magnetic field distribution were analyzed using COMSOL software. The sensitivity analysis experiment of the sensor for particles at different detection positions was carried out, and the dynamic experiment was set to detect the maximum flow rate of the oil under the normal working condition of the sensor, and the aliasing wear particles of different sizes were detected. The experimental results show that the sensor can detect ferromagnetic wear debris with a minimum diameter of about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~\mu $ </tex-math></inline-formula>m under the condition of a larger coil diameter. The sensor detection unit still has a good detection effect when the wear particles are adsorbed successively, and the experimental signal can be accurately reflected on the waveform diagram. The sensor proposed in this study has a probe diameter of 13 mm, a sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$28.119~\mu $ </tex-math></inline-formula>H/mg, and a resolution of up to 3.9%, which is high in sensitivity and resolution relative to the same class of sensors and can be better adapted to a variety of working conditions due to the large enough probe diameter. In addition, the structure of the sensor is simple, which provides a new idea for the research and development of oil detection equipment.