Research On Detection Of Metal Partical In Hydraulic Oil

With the widely application of hydraulic machinery in industrial production, the oil detection technology plays a more and more important role both in the prediction and the diagnosis of the hydraulic machinery fault. Though the metal particles pollutant in the oil is the important item to test the oil, it still cannot detect and count the common metal particles appeared in the oil, even cannot distinguish count. Therefore, there is some limitation on this kind of technology.First, this thesis introduces the origin and harm of the hydraulic oil pollutant, the importance of the oil analysis for the fault diagnosis and detection, the main way, advantages and disadvantages of the oil testing nowadays, and the major principle and limitation of the particle detection. Second, the principles of the inductive metal detection and the main application way of the metal particles detection were analyzed. And finally through the experiment, the detection chip of high sensitivity was designed. This experiment is mainly divided into three stages:The first stage:Static experiment. The influences produced by some basic parameters such as the inductance type, the incentive frequency, the incentive voltage, distance, location etc. on the detection sensitivity were measured in this stage. The metal particles with different size and nature were tested using the same inductance and from which make a conclusion.The second stage:the design and optimization of the detection chip. First, according to the actual application of the oil testing and the experimental results in the first stage, it puts forward the requirements of the detection chips, and then designs the structure and selection of the detection chips depending on the requirements; The next step is to produce the detection chips with the micro processing counting method and then optimized the test of the detection chips.The third stage:We know that both inductance coil and film inductor have the high rate of change through the experiment in the first stage. Using the detection chips as the carriers, this thesis studies the basic parameters of the inductance coil and film inductor. These parameters mainly include circle number, layer number, and the diameter of making inductance enameled wire and the coil diameter and so on. Through the analysis of the experimental results, the detection chip with high sensibility is designed and it realizes the distinctive testing of the 19um iron particles and the 40μm copper particles.