Design And Optimization Of Lightweight Screw Rotor With Hollow Inner Support

With the rapid development of industry and economy,air compressor has become one of the essential aerodynamic equipment in production and life,especially the screw compressor is widely used in medical equipment,coal metallurgy,electric power refrigeration and other fields.As the core component of compressor,the design and research of screw rotor’s end profile have been mature,but the research of lightweight structure design and rapid prototyping technology is currently being explored.In this paper,based on additive manufacturing technology,the lightweight structure design of the screw rotor with hollow inner support was carried out,and the simulation analysis and optimization of the lightweight structure of the screw rotor were carried out.In addition,the PA12GF40 was used as the processing material for rapid protoforming,and the forming quality of additive manufacturing technology was studied.The research contents of this paper are as follows:(1)The screw rotor is designed with hollow and equal wall thickness structure,and the supporting structure is added on the basis of the hollow and equal wall thickness,and the3 D modeling is completed with UG modeling software;The statics and dynamics simulation analysis of the lightweight rotor with hollow inner support was carried out.The deformation of the rotor with hollow inner support structure was analyzed by statics.It was found that the inner support structure could effectively reduce the deformation and improve the stiffness of the lightweight rotor.Through the analysis of the dynamic structure,the natural frequency and the change law of the mode shape of the free mode and the prestressed mode are obtained,and the dangerous frequency generated by the external excitation is analyzed.(2)Simulate the working process of screw compressor,change the outlet pressure,and get the internal pressure distribution rule of flow field with different outlet pressures;The internal flow field of the compressor and the static field of the lightweight rotor with internal support were coupled to analyze the deformation law of the solid rotor,the hollow rotor and the rotor with internal support structure and the influence of different outlet pressure on the deformation of the two structures under the condition of fluid-structure coupling.(3)Using the Design Expert in Box-Behnken module structures,the response surface model for optimization analysis,the optimal response factors,lightweight rotor determined response value and best response range,multiple regression equation model,through the analysis of response model,variance,standard deviation and response of the cloud of the optimum parameters of the optimization combination of lightweight rotor structure.(4)Rapid prototyping of the optimized model was completed by additive manufacturing technology,and the density,dimensional accuracy,surface roughness and tensile properties of the printed sample were measured to explore the forming quality and mechanical properties of the additive manufacturing formed parts.