Analysis of stress influencing factors in the spring tube screw connection assembly of electro-hydraulic servo valve

The armature assembly of the electro-hydraulic servo valve, featuring the spring tube as its core component, is essential for converting torque into displacement with high precision. During operation, the spring tube, in conjunction with the armature baffle assembly, undergoes micro-bending due to swinging motions, significantly affecting the mechanical properties and assembly quality, which in turn impacts the dynamic and static performance of electro-hydraulic servo valves. This paper investigates the evolution of stress and strain in the spring tube screw connection assembly under various operational conditions. The study begins with a simulation of the assembly process of the spring tube to determine the stress distribution patterns under different preload conditions. Concurrently, a comprehensive analysis of the stress relaxation characteristics of the spring t ube material is performed, along with an evaluation of the reliability of the predicted performance indicators for the spring tub e screw connection assembly under room temperature storage conditions.