Research on valve core’s clamping stagnation of double flapper-nozzle servo valve

作     者：Zhao Jianhua Zhang Bin Chen Tao Wang Qiang Zhou Songlin Gao Dianrong 赵建华;Zhang Bin;Chen Tao;Wang Qiang;Zhou Songlin;Gao Dianrong

作者机构：Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and ControlYanshan University 

出 版 物：《High Technology Letters》 (高技术通讯（英文版）)

年 卷 期：2019年第25卷第1期

页      面：65-73页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：Supported by the National Natural Science Foundation of China(No.51705445) Natural Science Foundation of Hebei Province of China(No.E2016203324) Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems 

主　　题：double flapper-nozzle servo valve flow-solid-thermal coupling numerical simulation catching phenomenon thermal deformation mechanism smooth movement 

摘      要：Due to great changing of instantaneous temperature of hydraulic oil of double flapper-nozzle servo valve, thermal deformation between valve core and valve sleeve may result in catching phenomenon of valve core, and then the reliability of servo valve could be affected seriously. The work focuses on a particular model of double flapper-nozzle servo valve and establishes three dimension couple models of liquid-solid-thermal under extreme operating condition. The transmission route and dissipative mechanism of heat is revealed and thermal deformation behavior of valve core and valve sleeve is researched. A change law of the key fit clearance under the effect of thermal expansion and warp deformation is explored, the source of catching phenomenon of valve core is identified, and then preventive measure and improvement can be proposed. In order to verify the correctness of theoretical analysis, the moving smoothness of deformed valve core and reground valve core under the circumstance of high-temperature hydraulic oil on electrohydraulic servo valve static characteristics test table is compared and tested. The results show that as oil temperature rises, relative deformations between valve core and valve sleeve in different direction at a same cross-section are not equal, and then the key fit clearance is less than the initial value. Relative deformations in the same direction at different axial position are not equal, the deformations of middle and two ends are maximum and minimum values respectively, and then warp deformation of valve core occurs. When oil temperature is higher, the relative deformations between valve core and valve sleeve is larger, the moving smoothness of valve core gets worse, and the catching phenomenon of valve core occurs. Axial deformation of valve sleeve and valve core at different axial position is different, and the opening coefficient and stability of servo valve could be affected, especially the operation circumstance of small opening. The