| Water hydraulic eletro-hydraulic servovalve as a new type hydraulic component which is inosculated of mechanical, electronic and hydraulic technology, it is one core control component of water hydraulic servo control system, and has many merits such as small volume, light weight, high control precision and fast response speed, it has also become a very important research object in the forefront of international fluid power field at present. Structure principle and work trait of jet pipe water hydraulic eletro-hydraulic servovalve (JPWHEHSV) developed by ourselves are introduced in the dissertation, and its mathematic model is set up, transfer function and quadrate charts are also founded out. According to analysis conclusion of system stability of JPWHEHSV, the condition for the control system stability is educed. In the thesis system simulation study has been completed using AMESim software, simulation result indicates that JPWHEHSV has good static characteristic and dynamic characteristic, this also illuminates that JPWHEHSV has perfect static and dynamic characteristics which include nicer control stability, quickly response and perfect control precision. Using AMESim software, system simulation and parameters tenderness disquisition of JPWHEHSV are completed to find out the variational trend and effect in this thesis, these parameters mainly include the clearance between valve spool and sleeve, overlap length of slide valve orifice and mass of valve spool.According to framework in the jet flow ejection and receiving area of JPWHEHSV, this thesis has built 3D grid model for key jet flow domain using CFD software, and flow field characteristic in key area has been simulated using FLUENT software. The influences of fluid characteristics caused by the geometry structure parameters and system boundary conditions of WHJPEHSV are especially investigated in the dissertation. This has laid the theoretical foundation for the optimization design of JPWHEHSV. For compariation of simulation conclusion, many models with different geometry framework parameter has been built in the thesis, simulation endings of different flow field are compared, the simulation result indicates that the geometry model has perfect flow field characteristic when geometry framework parameter d1 (diameter of jet pipe) and d2 (diameter of jet receiver pipe) are 0.3mm, the clearance between jet pipe and jet receiver b is 0.5 mm, and angle between two jet receiver pipesαis 45°. This conclusion offers theory thereunder for the development sample of JPWHEHSV.According to the physical and chemical characteristic differences between water and oil, applicabilities of water hydraulic element and system are introduced in the dissertation, and methods and measure about optimizing structure and choosing manufactural materials are also established, which can solve the problems including erode, cavitation, abrasion, vibration and noise. Development sample of JPWHEHSV (upmost working pressure is 14MPa and rating flux is 40L/min) and water hydraulic eletro-hydraulic servovalve multifunctional CAT experimeantal stage are developed by ourselves, experimental research about characteristics of JPWHEHSV has been put up using the CAT experimeantal stage, the test results indicates that the technological performance parameters of JPWHEHSV prototype developed by ourselves reach the study object preconcerted by this task research; the test result and the simulation conclusion using AMESim software are more identical. It also showes that the design theory, simulation model and theory analysis of development sample are rational, adopted method is feasible.
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