Tooth Profile Design And Process Technology Research Of Two-stage Oil-injected Screw Compressor

Screw compressor is broadly used in various industrial sectors such as mining,metallurgy, dynamic force, construction, machinery, refrigeration, chemical industry etc.Screw compressor, with a wide range of capacity, output pressure and workingconditions, has gradually substituted other types of compressors on a large scale due tothe feature of low noise and vibration level, high reliability, convenient operation andmaintenance, outstanding dynamic equilibrium and good adaptability. Consequently,screw compressor has very broad market. However, the development of our screwcompressor is mainly in the stage of imitation and the products, which has a bigdisparity for instance low discharge pressure, large power loss, unstable movement,big noise, fast wearing and short life compared with similar foreign, always cannotachieve the desired effect. And the production of screw compressors in our country areoften involves only in medium&low pressure models and there is hardly any researchof screw compressor with high pressure or multicompression. All of these have greatlylimited the development of related industries. Therefore, the research of the design andtheory of two-stage oil-cooled screw compressor will be very significant.The main content of the thesis is as the following：①Working principle and structure characteristics of screw compressor areanalyzed and design principles and methods of shaped conductor are researched. Thenthe end tooth curves of male and female rotors are designed and the equations of screwhelicoidal surfaces are deduced.②Geometrical characteristics of rotors on two-stage screw compressor areresearched by using engagement theory and differential geometry. The main parametersare calculated and then selected according to working conditions. Air displacement ofcompressor and the quantity of the oil which is needed for cooling are calculated, thenthe structure of suction and exhaust orifice are designed, and last driven approach of themachine and the regulation of air displacement are analyzed.③The machining tool of rotors, which is critical component of screw compressoris researched deeply combined with the spatial meshing theory and tool profiledesigning theory. Machining tool and processing method of rotors are designed on thebasis of studying shaped conductor of tooth profile.