Mechanics Analysis And Optimization Research On The Key Structure Of Vacuum Gate Valve

Vacuum gate valve,as a indispensible and widely used part in the vacuum system,plays an important role in connecting the pipeline,cutting off the pipeline and regulating the gas flow.The composition of the vacuum gate valve and the relevant theories were introduced firstly in this paper.Currently,the vacuum gate valves are only used in the vacuum systems with high cleanness requirement.Compared with the oversea products,the vacuum gate valve made in China has a low cleanliness and out gassing rate and high air leak rate.Moreover,as a vacuum unit,the vacuum gate valve in our country has an imperfection of short service life,which significantly increases cost of the vacuum system.China’s valve industry since 1980s has made tremendous progress on both the design and manufacturing of the valve,and its overall level gradually caught up with that in American and European countries.But the overall quality of our valve products is still uneven,and the detection level and the manufacturing technique still fall behind which hinder our valve products from entering the international markets.Therefore,it is imperative to reform and innovate the technology of the design,development and manufacturing in our country’s valve industry.Based on the structural characteristics of the gate valve and the operating principle of the movement mechanism,the optimization design of the movement mechanism was conduced in this thesis.The structural model of the valve casing was established in Ansys,and the stress and deformation were analyzed.Based on the analysis results,considering the requirements of the structural strength and stiffness,the structure size of the valve casing was optimized by wall thickness.Based on theoretical mechanics,the movement features of the sealing mechanism of valve casing and the states of the different structures in critical points were analyzed,and the bearing life was also checked.The section areas and lengths of the bars in the four-bar linkage were optimized based on the optimization theory which guarantee that the connecting rod can be stressed uniformly and the drive can be smoother and more steady.Through the analyses on the mechanical characteristics of the valve casing of the vacuum gate valve and the dynamics of the sealing mechanism,some suggestions for optimizing the structure of the paddle valve are proposed which is beneficial for increasing and maximizing the role and the value of vacuum system.The work in this thesis will provide a theorical basis for designing the structure of the gate valve.