Research On Sensitivity And Throughput Enhancement In Wear Debris Inductance Detection

Detecting wear debris in lubricant oil is of great significance for analyzing mechanical wear status and condition-based maintenance.Inductance detection is an important method to detect wear debris in lubricant oil.The use of high sensitivity detection method to detect small size wear debris can predict wear failure earlier.The use of high throughput detection method can detect multiple parts of machinery.So improving the sensitivity and throughput of inductance detection is always the focus of research.This article theoretically analyzed the role of metal particles in the magnetic field,studied the application of magnetic materials to improve the sensitivity of the inductance detection,and studied the increase of the inductance detection throughput based on the phase division multiplexing.Specifically,the research contents of this article mainly include:(1)Based on the basic theorem of electromagnetics,the magnetization effect and eddy current effect of metal particles were analyzed,and the magnetization model of metal particles in the inductance detection was established.Based on the vector potential,the relationship between metal particles and the surrounding magnetic field was analyzed,and the influence factors of the change of inductance caused by metal particles were studied.The results showed that the influence of metal particles on the magnetic vector potential of the magnetic field is related to the original magnetic field strength,the frequency of the excitation signal,the particle size and attribute,and the amount of change in the inductance detected by the metal particles is related to the volume and permeability of the metal particles.(2)On the basis of theoretical analysis,an inductive detection sensor using magnetic materials was designed and an experimental system was built.The influence of magnetic powder concentration on the inductance detection signal was studied.The comparison experiment of inductive sensor with or without magnetic material was carried out by using different sizes of iron particles.The detection limit of inductive sensor with or without magnetic material was verified by experiment.And the sensor with or without magnetic material was used to detect the wear debris in lubricant oil.The results showed that the inductance change of the inductive detection sensor is linearly related to the concentration of magnetic powder.The detection sensitivity of the inductive detection sensor with magnetic material is significantly higher than that of non-magnetic material sensors,and the smallest diameter of iron particles can be detected is 11 ?m.(3)A multi-channel inductance detection method based on phase division multiplexing technology was proposed,a four-channel inductance detection system based on phase division multiplexing technology was designed,the circuits of each module of the detection system were designed and studied,and an experimental system was established.The feasibility of the system was verified by experiments,the mechanism of interference signals in the experiment was analyzed,and the interference signals were eliminated.The results showed that by reducing the signal amplitude or increasing the signal threshold voltage,the interference signal can be reduced and eliminated.The four-channel inductance detection system based on phase division multiplexing technology can increase the detection throughput.