The flow field modeling and performance analysis method for the pilot stage of deflector jet servo valve

The deflector jet servo valve (DJSV) is a critical component in modern hydraulic control systems, widely used in aerospace, industrial automation, and precision machinery due to its high response speed and reliability. The pilot stage, as a core component of the servo valve, plays a crucial role in converting the displacement signal from the torque motor into the pressure signal to drive the movement of the power stage spool valve. However, the pilot stage flow field structure of the DJSV is intricate, involving multiple phases of energy conversion, and existing studies lack a complete mathematical model that can accurately describe its performance. This limitation has hindered the optimization of servo valve design and performance analysis. To address this gap, this paper proposes a novel method for modeling and performance analysis of the pilot stage flow field of the DJSV. Based on the working principles of the pilot stage and the mechanisms of energy transfer and conversion during the jet flow process, the pilot stage jet flow is divided into five distinct phases to develop a mathematical model of the flow field. Furthermore, the performance of the pilot stage and the influence of key structural parameters are analyzed, then a mapping relationship between them is established. This paper conducted a pressure characteristic test of the pilot stage to verify the correctness of the proposed method. The proposed model offers significant practical value for optimizing servo valve design, reducing development time, and improving system performance in various industrial applications.