Research On Influencing Factors And Rules Of Metal Particle Detection Based On Micro Inductive Sensor

As the blood of mechanical equipment,lubricating oil can cool,clean and reduce the wear of mechanical parts.But it will inevitably be affected by ’various kinds of pollution in the work,affecting the normal operation of the equipment.Among all kinds of pollutants in oil,solid particles are the main cause of mechanical wear,and metal particles are the main pollution source.By detecting the nature,size and quantity of the metal particles in the lubricating oil,the wear materials in the system can be distinguished accurately,and the source of the metal particles and the wear state of the relevant friction pairs can be determined.This method can save the maintenance cost,improve the reliability,reduce the accident rate and prolong the mechanical life.Firstly,this paper points out the causes,sources and hazards of metal particle pollutants in lubricating oil,and briefly introduces the research status of particle detection technology at home and abroad,as well as the advantages and disadvantages of various detection methods.Then the principle of metal particle detection is analyzed.Finally,a kind of micro inductance sensor is designed and manufactured,and the experimental research of metal particle discrimination detection is carried out on the sensor.The main content of this paper is divided into the following parts:(1)The distribution characteristics of magnetic field in the micro inductance coil are studied.The magnetization model of metal particles in the micro inductance coil is established.The mathematical model of the influence of eddy current in the metal particles on the impedance of the micro inductance coil is established.The theoretical study shows that the magnetization field of metal particles changes the equivalent inductance of the micro inductance coil,while the eddy current field changes the equivalent inductance and the equivalent resistance of the micro inductance coil at the same time.(2)Using COMSOL finite element analysis software,the distribution characteristics of magnetic field in the micro inductance coil are simulated.The effects of the parameters of micro inductance coil,metal particle and excitation signal on the change of equivalent impedance of micro inductance sensor are studied.The relationship between the parameters and the change of equivalent impedance of micro inductance sensor is determined.(3)The experimental system is designed and the metal particles and micro inductance sensor are made.Combined with the simulation results,the effects of sensor parameters,particle parameters and excitation source parameters on the output impedance of the micro inductive sensor are experimentally studied,and the accuracy of the simulation results is verified.