Design And Analysis Of Compound Texture Core For Safety Valve Of Water Hydraulic Support

Hydraulic support safety valve,as the core component of equipment support safety,has a decisive impact on the reliability,safety and service life of support equipment.Usually the working medium of hydraulic support is emulsion,but the emulsion is easy to deteriorate,which will lead to blockage of filter equipment,thus affecting the work schedule,reducing the service life of safety valve,and causing pollution to the environment.With the proposal of sustainable development strategy,the State advocates the construction of green mines,so the hydraulization of coal mine machinery has become a hot research direction of water hydraulic technology.However,due to the low viscosity of water,high pressure and high flow rate of coal mining machinery,there will be lubrication,friction and wear,cavitation and other problems in hydraulic machinery.In this paper,the safety valve in water hydraulic support is taken as the research object,and the working medium emulsified liquid is replaced by water.The key problems such as lubrication and cavitation erosion of the safety valve in water hydraulic support are mainly studied.It will provide theoretical and technical support for future research on mine machinery water hydraulization.The main contents of this paper are as follows:1.A new structure of composite texture valve core is proposed.The composite texture was introduced to the surface of the safety valve core of the hydraulic support,and the lubrication and wear reduction of the friction pair between the safety valve core and the valve sleeve were studied.By establishing a composite texture lubrication model,the dynamic pressure lubrication characteristics and wear reduction mechanism of the composite texture valve core were analyzed.In order to solve the problem conveniently,the composite texture of the valve core is simplified to a L1 *l2 micro-element.Different parameters of area ratio,depth and arrangement order are set to simulate the composite texture unit of the valve core.The surface pressure nephogram,the central section curve and the surface bearing capacity of the valve core are obtained.By comparing with single texture with the same parameters,the advantages of composite texture are illustrated,and the effects of depth,area ratio and arrangement order on the lubrication characteristics of composite texture core are analyzed.A group of composite texture of valve core which can produce good hydrodynamic lubrication characteristics is optimized.2.A new concept of radial hole of variable cross-section relief valve core is proposed.Aiming at the cavitation problem in the radial hole of the valve core of traditional water hydraulic support,six new structures of variable cross-section radial hole are designed.The CFD model of variable cross-section radial hole was established,and the structure of the radial hole was optimized.The cavitation erosion reduction method at the radial hole of the valve core was studied.Through simulation,pressure nephogram,streamline diagram,turbulent kinetic energy nephogram and vapor volume fraction diagram of six kinds of variable cross-section radial pore structures are obtained.The comparative analysis shows that the circular platform radial pore structure and the spherical radial pore structure have better cavitation resistance,but considering the influence of processing technology and cost,the positive platform radial pore structure with the best cavitation resistance is optimized.It can effectively reduce the occurrence of cavitation at the radial hole of the spool.Figure [43] Table [5] Reference [88]...