Research Of Detection Of Lubricants Metal Particles

Lubricant is regard as “Blood”, it’s indispensable and widely used in mechanical devices. Solid pollutants, especially metal particles play an important role in wear, which is considered as the main reason for the malfunction of mechanical devices. Recently, Lubricants metal particles detection technology as a mean to monitor mechanical devices running condition, receives much emphasis. Lubricants metal particles detection technology is able to detect kind, dimension and quantity of metal particles to analyze the wear condition and predict its breakdown, so to prevent serious accident caused by wear. However, the existing metal particles detection sensors have such disadvantages as low measure precision, high cost and technical barrier. Therefore, it is necessary to make further research on metal particles detection technology and develop a reliable detection sensor.According to detection requirement and metal particles character, this thesis studies the metal particles detection technology based on the principle of electromagnetic induction. The main contents include:Through research on detection principle, mathematical model and detection characteristics, to determine the structure of the sensor and detecting circuit. According to the characteristics of the sensor output signal, a data acquisition system is design. The data acquisition system includes three parts: Keysight 53230 A frequency counter, Keysight Command Expert and MATLAB. Using moving average filtering algorithm and median filtering algorithm to deal with collection data, information of metal particles can be obtained.Then, there experiment tests for the sensor have been done. The sensor calibration test shows that the sensor can effetely distinguish between magnetic and non-magnetic metal particles. Under laboratorial condition, the sensor can detect the minimum diameter of magnetic particles and non-magnetic particles respectively 50μm and 100μm. The engine test shows that the sensor has good detection ability for the metal particles in engine oil. Through the reciprocating friction pair wear test, to obtain the wear quantity of the friction pair, then using the change of wear quantity to carry out preliminary discussion of the wear failure early warning model.