Technical Study On Micro Inductive Sensor For Metal Debris Static Detection

Wear metal debris produced by the friction pair suspends in the machinery oilsystem while the concentration, composition, size and morphology of the debris arechanging with the increasing equipment working hours and the different wearconditions. About82%of the wear failures are caused by the metal debris. Therefore,it has important research significance to detect the metal debris of the oil used in themachinery equipment while it can forecast equipment wear failure and reduce majoraccident and economic loss.First, this article discusses the research status about metal debris detection in theoil, and proposes the research on micro inductive sensor for the static detection ofmetal debris. The micro inductive sensor is designed and the coil structure is spiralplanar.Secondly, this article proposes the calculation method based on segmentationmethod and Jenei method, while taking advantage of the COMSOL Mutiphysics to dothe simulation analysis about the effect of metal debris effect tatic detection.Thirdly, focus on the key process for the production of micro sensor, includingsputtering process, etching process and electroplating process, and then design theMEMS processing to make the micro sensor according to the lab condition andeconomic cost.At last, in the static detection experiments based on the micro sensor, a sensorcalibration device is designed to detect the metal debris. The micro metal debris isdivided into ferromagnetic and non-ferromagnetic. The ferromagnetic micro metaldebris mainly contains iron debris, steel debris and nickel debris, andnon-ferromagnetic micro metal debris is mainly copper debris. According to thetheoretical simulations and experiments, the steel debris has the most obvious impactto enhance the inductance value of micro-coil, and the change rate of inductance valueis0.13%. The second is nickel debris which causes the inductance value change rate0.1%. The last is iron debris which causes the inductance value change rate0.05%.The weakening effect of the copper debris on the micro-coil inductance value is alsosignificant, the inductance value change rate caused by copper debris is-0.1%. It proves the non-ferromagnetic micro metal debris can lead to lower inductance valuewhile the ferromagnetic micro metal debris can increases inductance value based onthose experiment data above.Therefore, the static detection experiments can provide theoretical guidance tothe metal debris dynamic detection in the oil, and the micro inductive sensor is rarelyaffected by air bubbles and water in the oil, so it is an important significance to do theresearch about metal debris on-line detection in oil.