Abstract:Electro-hydraulic servo valve is an important control component of the aerospace precise electro-hydraulic servo system, and the armature assembly is the key component responsible for the electro-hydraulic conversion of servo value. To ensure the high precision and sensitive amplification output of attitude control signal, the armature assembly is required to have extremely high position and dimension accuracy, the design of interference fit parameters is very important. Based on the interference fit principle of the thick wall cylinder, the reasonable range of interference is determined by the parts material yield limit theory. The equivalent stress of the original armature assembly exceeds the material yield limit, which is an important reason for the damage of the tube spring. Through assembly and testing of the armature, the problems such as excessive pressure deformation, parallelism, and damage of pipe spring are solved, and the reliability and the qualified rate of interference fit joint originally have a very big promotion. The design parameters determined with the proposed approach in this paper can better satisfy the requirements of the products.