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Hydrostatic drive technology as a medium to sea (light) water, with no pollution, no burning, energy conservation, the working medium is easily accessible and prominent advantages are increasingly subject to a wide range of domestic and international engineering community attention. Hydraulic servo control technology is an indispensable part of water pressure technology, water pressure technology is a very important development branches and direction, and has become the forefront of the discipline is a very important research topic. Hydraulic servo valve is a combination of mechanical, electronic and hydraulic technology, high-precision components, its performance directly affects the performance of the entire hydraulic servo system. According to the characteristics of the water with a hydraulic servo valve, hydraulic bridge circuit using the the two fixed orifice nozzle flapper series structure. Focus on water hydraulic servo valve hydraulic the Kiu flow characteristics, and explore the nozzle flapper displacement, the relationship between both ends of the spool movement speed and spool pressure; nozzle diameter, series fixed orifice diameter, the spool diameter and its movement speed, nozzle flapper-nozzle the initial distance parameters for hydraulic bridge circuit characteristics. Bridge characteristics of the interaction between the change of each parameter and the parameter analysis of orthogonal design, laid a theoretical foundation for the design of the hydraulic servo valve. Conducted a theoretical analysis of the static characteristics of the hydraulic servo valve and its transfer characteristic is obtained a block diagram showing a hydraulic servo valve system feedback obtained, according to a block diagram of the transfer function of the servo valve system, the simulation of the transfer function derived its primary Testo, verify the stability of the servo valve system. CFD software - on the the tandem the nozzle flapper hydraulic bridge circuit by two fixed orifice nozzle flapper application commercialization FLUENT, the introduction of mass transfer equation, the gas volume equations and the RNG k? Ε turbulence model, its flow characteristics and cavitation characteristics of a comprehensive simulation study. Two fixed orifice has two structural forms, is a two are thin-walled orifice, the other one is a thin-walled orifice, an annular disc slit. Changing the diameter of the fixed orifice, the annular gap and overlap length of the circular slit, the nozzle flapper displacement parameters, obtained the flow characteristics of of nozzle flapper hydraulic bridge circuit in different geometric conditions and boundary conditions. Through the technological transformation of existing test bench, to design the nozzles of different shapes and sizes, ring round seam, fixed orifice combination specimens were studied on the flow characteristics of the nozzle flapper hydraulic bridge circuit, The nozzle flapper on fluid power were related tests. On the basis of the above research work, completed the design and manufacture of hydraulic servo valve; using existing test equipment, design the static characteristics of the hydraulic servo valve test rig, developed a test device hardware interface circuit, preparation function data acquisition software, completed Experimental study of the static characteristics of the hydraulic servo valve. The no-load flow characteristics of the hydraulic servo valve, the load flow characteristics, the internal leakage and the pressure characteristics and the correlation analysis, and on this basis, the hydraulic servo valve bias, hysteresis loop, flow gain, the pressure gain and non-linear linearity as well as the degree of asymmetry characteristics related research.
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