Research on Typical Wear Fault Diagnosis of Electro-Hydraulic Servo Valve Element

Electro-hydraulic servo valve is the key element of hydraulic servo system. The failure of electro-hydraulic servo valve has great influence to the reliability of hydraulic servo system. The valve element wear failure has a highly frequency and concealment. Failure simulation technology has been widely used in astronautics field, and it also made success in other field. Composition and structure of electro-hydraulic servo valve have been studied in this paper. Mechanism of hydraulic wear fault which mostly caused of abrasion has been discussed. Mechanism study is an important session of failure diagnosis. Model of electro-hydraulic servo valve was built and simulated by using AMEsim. The valve element failure features knowledge base was built by using electro-hydraulic servo valve element wear failure information according to the simulation model. Flow characteristics under different wear condition were simulated by valve element wear simulation. Simulation data was got and simulation curve was fitted. Different degree of valve element could be distinguished by Support Vector Machine (SVM) model, which was trained according to simulation data. The effectiveness of electro-hydraulic servo valve simulation model was validated in this paper.