Research On On-Line Monitoring Method Of Ferromagnetic/Non-Ferromagnetic Metal Wear Particles In Lubricating Oil

The oil debris on-line monitoring technology of the lubrication oil is urgently needed for wear evaluation and early failure warning of mechanical equipment.Among them,the inductive oil debris monitoring method based on the principle of electromagnetic induction can meet the full flow and real-time online monitoring of lubricating oil debris.The detection capability of the inductive oil debris sensor is improved by improving the structure of the sensor,adding the built-in magnetic core,increasing the number of excitation coils or optimizing the weak signal processing circuit.However,the influencing factors rule of the the inductive oil debris sensor detection performance are unclear,and the analysis of the electromagnetic characteristics of ferromagnetic and non-ferromagnetic wear debris in the alternating magnetic field is insufficient,resulting in high false alarm rate and large error in the detection results of wear debris,which cannot accurately acquire the information of the oil wear debris under the actual working conditions.To solve these problems,the following studies are carried out in this paper:（1）Based on the electromagnetic effect of metal wear debris under alternating magnetic field,the working principle of the sensor is is analyzed and summarized.The magnetic field inside the sensor is studied.On this basis,the mathematical model of the output signal of the sensor is established,which provides reliable theoretical guidance for the optimal design of the sensor.（2）The simulation analysis model is established to extract the output signal of the wear debris through the sensor detection area,and the mapping relationship between the output signal and the characteristics of the wear particle is excavated to provide method support for the accurate measurement of the wear debris.（3）The influence of sensor structure parameters（pipe diameter,coil spacing,coil layer number）,wear debris parameters（material,size）,excitation frequency and multiple wear debris（different gaps,different distribution positions）on the detection performance of inductive wear debris sensor is obtained by simulation analysis,and the influence laws of various factors are analyzed and summarized.（4）In order to verify the correctness of the test model of the lubricating oil wear debris detection and the influence rules of different parameters on the output signal of sensor,the three-coil structure sensor is designed and the experimental platform of the lubricating oil wear debris detection is constructed.The relevant experiments are designed,and the detection experiments of different materials,different sizes and multiple wear debris are carried out.The research in this paper provides guidance basis and direction for the high sensitivity optimization design of inductive oil debris monitoring sensor,and the research results provide a new idea for the application of oil wear debris monitoring technology.