Study On On-line Monitoring Sensor Of Oil Metal Wear Debris

In this study,the object is the on-line oil metal wear debris monitoring sensor which is used in the integrated transmission system of armored vehicle.In order to solve the problem that the detection precision of sensor cannot satisfy the needs of on-line oil debris monitoring,the new mathematic model and internal circuit model were established.The magnetizing mechanism offerromagnetic metal debris in alternating magnetic field was analyzed.The on-line monitoring sensor was manufactured based on analysis simulation result.Test with and without oil were conducted separately and test data was collected and analyzed.The test result shows that: new on-line monitoring sensor increases detect precision of ferromagnetic debris and non-ferromagnetic debrissignificantly.And this study is meaningful to future application of on-line oil debris monitoring.The main research contents were as follows:(1)Based on the Maxwell equations,the magnetizing mechanism of metal debris in alternating magnetic field was analyzed,whichis the theoretical basis of mathematic model.Based on the Biot-Savart law and Faraday's law of Electromagnetic Induction,mathematic model of sensor was established.The effect of different parameters on detection precision was obtained by simulation calculating in MATLAB.The 3-D model of sensor was built,whose parameters were based on MATLAB simulation results.The validity of sensor model was verified by 3-D simulation in J-MAG.(2)In order to increase detection precision to ferromagnetic debris and non-ferromagnetic debris,the circuit of sensor was designed based on magnetizing mechanism.LC oscillation circuit was introduced into sensor circuit,which is benefit to filter high-frequency noise and increase signal to noise ratio.(3)Integrated on-line monitoring detect system was established and test bench with and without oil were built.Test scheme was drafted,which contains rotate speed of vane pump,inductive frequency and current amplitude.Test with and without oil were conducted separately and test data was collected.Comparison between test data and simulation result verified the validity of sensor model.Comparison test between Metalscan sensor and the sensor designed by ourselves were conducted and test data was analyzed.Under actual lubricate condition,detect precision of ferromagnetic debris increased from 200?mto 80~90?m,and non-ferromagnetic debris increased from 400?mto 200?m.The result of test means the sensor has reached an advanced level in China and provides guidance to follow-up actual test.