基于GMR磁传感器的小尺寸铁磁性磨粒监测技术

Monitoring Technology of Micro-sized Ferromagnetic Particles Based on GMR Magnetic Sensor

为在线监测机械设备润滑油中的铁磁性小颗粒,设计并搭建了一套在线监测实验平台,利用永磁铁聚集并磁化循环油路中的小尺寸铁磨粒,基于巨磁电阻磁传感器的磁敏特性监测磁化磨粒的剩余磁场,分析提取磁场信号特征指标从而获取磨粒信息。研究了测试系统的磨粒检出能力、输出信号强度与永磁铁位置、磨粒含量、磨粒尺寸之间的关系。结果显示:聚集法显著提高了磁传感器芯片对75μm以下小尺寸铁磁性颗粒的检出能力,且检测信号强度可基本反映磨粒尺寸及浓度含量。表明对磨粒进行磁性聚集后可利用巨磁电阻磁传感器有效实现对设备早期磨损故障的在线监测。

In order to monitor oil micro-sized ferromagnetic particles of mechanical equipment,an on-line monitoring experimental platform was designed and constructed.Permanent magnet was used to collect and magnetize micro-sized particles in circulating oil circuit,the magnetic sensitivity of giant magnetresistance(GMR)magnetic sensor can be used to measure the residual magnetic field of magnetized particles,debris information may be obtained by analyzing and extracting characteristic indexes of magnetic field signals.Test system s ability to detect wear debris and relationships among output signals intensity,position of permanent magnet,wear particles quantity and size were studied.The results show that aggregation method can significantly improve sensor s detection ability of micro-sized ferromagnetic particles less than 75μm,and the detection signals intensity can basiclly reflect their sizes and concentrations.It demonstrates that GMR magnetic sensor can effectively realize on-line monitoring of equipment early wear faults when wear debris gathered by magnetic field.