Analysis of clearance flow field of integrated mechanical-hydraulic servo spool valve for fan

JIA Yong-shuai, SU Dong-hai
(College of Mechanical Engineering, Shenyang University of Technology, Shenyang 110870, China)

Abstract: Aiming at the problem of clamping and large leakage of the mechanicalhydraulic servo spool valve, the flow field of the fit clearance at the mechanicalhydraulic servo spool valve of the fan was analyzed. When the spool valve was pour tapered, the effects of eccentricity between the spool valve and the sleeve, the taper of the spool valve and of the servo valve rotating at a high speed of 1 500 r/min on the flow field in the spool valve clearance were studied respectively. The simulation software was used to analyze the flow field changes of the clearance between different spool valve eccentricity and taper of the spool valve, the dynamic performance of the high-speed rotating integrated mechanical-hydraulic servo-hydraulic cylinder was simulated and compared to analyze the characteristics of the fluid field of the mechanical-hydraulic servo spool valve with the gap, the allowable range of eccentricity and taper of the integrated mechanical-hydraulic servo spool valve was obtained. The results indicate that in order to ensure the dynamic performance of the servo valve and ensure the system has good stability，the eccentricity of the mechanical-hydraulic servo spool valve should not exceed 0.01 mm，the radius difference of pour tapered of the mechanical-hydraulic servo spool valve should not exceed 0.015 mm. The results can lay a foundation for the structural optimization analysis of the mechanical-hydraulic servo hydraulic cylinder.
Key words: mechanical-hydraulic servo spool valve; fit clearance; flow field analysis; radial force; leakage