Research On Sealing Characteristics Of Hydraulic Cylinder For Pure Water Hydraulic Support

Hydraulic support is an important support equipment in the process of coal mining,at present,hydraulic supports use emulsion as the working medium.Emulsion is composed of water,base oil and chemical additives with various components,and it is easy to deteriorate,with high cost of use and maintenance,also with leakage and environmental pollution.So,the application research of hydraulic support using pure water as the transmission medium has attracted people's attention.Due to the low viscosity of pure water,hydraulic components are more easily likely to leak when they work,the leakage sealing problem of the hydraulic support column is always one of the main problems in the application of pure water medium hydraulic support.The thesis takes the sealing of the piston rod of the hydraulic support of hydraulic cylinder for hydraulic support with pure water medium as the research object,through theoretical analysis,Structural design,modeling,structural optimization,sample test analysis and other methods,The sealing characteristics of the piston rod of hydraulic cylinder for hydraulic support with pure water medium are studied.The main research work of the thesis is as follows:(1)Analysis of the characteristics of the interface fluid in reciprocating piston rod sealsAccording to the characteristics of pure water medium,the boundary layer state of its sealed interface is determined by boundary layer theory.Through the analysis of the internal and external stroke of the piston rod,it derive the calculation formula of the leakage amount of the piston rod movement for one cycle,according to the N-S equation,it deduce the contact stress calculation formula for the reciprocating dynamic seal and static seal of the Lei-ring combined seal,the influence factors of contact stress of dynamic and static seal are analyzed.(2)Design a new type of Lei-ring combined seal structureCombined with the sealing characteristics of pure water hydraulic cylinder and the chemical and physical characteristics of pure water,through analysis and comparison of existing Lei-ring combined seals and seal groove forms,to summarizes the application status and characteristics of Lei-ring composite seals;by carrying out research on the sealing structure of the piston rod.And use CAD/UG and other design software,designed a new Lei-ring combined seal structure for piston rod seals.(3)Structural simulation analysis using ANSYS softwareSimulation analysis of the new type of Lei-ring combined seal structure was carried out.The new sealing structure is modeled by ANSYS software,in order to get stress-strain cloud diagrams.The von Mises stress criterion was used to evaluate and analyze the test results.By extracting the contact stress curve during the analysis,the structure optimization analysis is carried out,and a new type of Lei-ring seal structure for pure water medium working conditions is obtained.(4)Prototype production and testFor new type of Lei-ring combined seal with design,the trial production of sample and design of experiment scheme is carried out,the experimental scheme of the new type of Lei-ring combination seal suitable for pure water medium is designed,and through the sample test to check the sealing performance of the new combination seal,and to ensure that the seals meet the requirements for the use of pure water medium hydraulic supports.