Design and construction of interference fit testing system for electro-hydraulic servo valve nozzle

Abstract The interference-fit assembly process for shaft holes is characterized by its simplicity, high-quality control, and efficient, pollution-free characteristics, making it widely used in the industrial manufacturing field. The force feedback mechanism of the electro-hydraulic servo valve plays a crucial role in system operation, with very high-reliability requirements. Key components within the force feedback mechanism require interference-fit assembly, but during assembly, the instantaneous fluctuations in friction force can lead to imprecise control of axial displacement. Therefore, an in-depth study of the friction process during the nozzle’s interference-fit assembly is necessary. This paper proposes a method for measuring the radial force exerted by cylindrical closed surface contact during the study of the interference fit between the nozzle and the bottom hole of the electro-hydraulic servo valve, laying a significant foundation for further enhancing the precision of nozzle assembly displacement.