Study On Flow Field And Clearance Leakage Of Integrated Transmission Hydraulic Spool Valve

In the study,the object is the buffer shift spool valve used in the integrated transmission of a armored vehicle,CFD calculation models of spool valve were established.Visualization research for internal flow field of spool valve by using FLUENT software,obtained the flow field characteristics and change rule of steady state flow force under the valve different working conditions.Aiming at the clearance leakage of spool valve in polluted environment,two-dimensional geometric models with different clearance were set up,which considering the effects of the clearance,particle diameter,density and the concentration of the polluted oil.The distribution of particle and the clearance leakage have been numerically simulated by the FLUENT software,then test bed was designed to verify the above simulation.The research results are significant for the flow field visualization research of spool valve,the design of fit clearance can be used to forecast the working condition in polluted environment.The main research contents were as follows:(1)The model of flow region was built by using CATIA software,which simulated by using FLUENT software.The flow field characteristics under different working conditions were obtained,and then the change rule of steady state flow force according to the flow field was studied,furthermore,the effects of diameter of axle on steady state flow force was considered.As to the results of simulation,modified model of steady state flow force was obtained.(2)Aiming at the situation of spool valve with polluted particles,the movement characteristic of polluted particles in hydraulic oil were explored,the morphology and size distribution characteristic of polluted particles were analyzed in hydraulic oil by experiment,and then the distribution characteristic of particle in spool valve was simulated by FLUENT.(3)Aiming at the phenomenon of the polluted particles flow into the fit clearance of spool valve,the flow field of particles in clearance fit was explored,and then influence factor of the distribution of particles was analyzed.The clearance leakage have been simulated,the change rule of leakage with the changing of clearance and particle concentration was obtained,which proved by experiment.(4)An experimental system to test spool valve leakage with polluted particles was established,Air Cleaner Fine Test Dust(ACFTD)was used to compound different particle concentration of polluted oil,the relationship of leakage with different particle concentration at different clearance was researched.