Research On The Design Of Structure Parameters Of Large Centrifugal Compressor Impeller Curvic Coupling

The curvic coupling structure has the advantages of large transfer torque,high assembly efficiency,good to neutral,less connecting bolts,stable transmission,long life and so on.As the compressor of the working machine,not a lot of curvic coupling are used to connect the impeller with the spindle.Impeller compressor is the core component,its dynamic characteristics in a certain extent,decided to compressor working performance of the machine,and the impeller curvic coupling as the main shaft torque of features,the current domestic haven’t mature design method of impeller curvic coupling,the strength calculation method,etc.,in addition,because of the existence of transverse tooth structure causes the rotor structure of discontinuous,continuous structure has weakened its stiffness,has certain influence on rotor vibration characteristic analysis,therefore,its stiffness calculation method and the rotor vibration characteristic analysis method needs special refining.Therefore,the purpose of this paper is to propose a design method for curvic coupling,strength calculation method,stiffness calculation method and corresponding rotor vibration characteristics analysis method by referring to the existing experience at home and abroad.The research is carried out around the design of straight curvic coupling.The main research contents of this paper include:(1)According to the meshing principle of curvic coupling,the design formula of main parameters of curvic coupling is derived.The correctness of the main parameter design formulas is verified by comparing with the existing standards and design examples.Modeling was carried out by large-scale commercial 3D software,and the correctness of the design equation was verified by finite element contact stress analysis.(2)According to the force analysis,a suitable formula for calculating the bending strength is given,and the feasibility of the formula is verified by finite element analysis.According to the bending strength calculation formula,the influence law of the main parameters of curvic coupling on the bending strength is analyzed,which provides the basis for the subsequent tooth type optimization and provides the direction for the actual engineering design process(3)Based on the stress analysis of single tooth on tooth surface and the compression model of rigid flat punch,the formula for calculating the average contact stress on tooth surface and the formula for calculating the linear average stress along the direction of tooth width are derived,and the distribution law diagram of contact stress is drawn according to the calculation results,which provides the basis for the optimization of tooth type of curvic coupling and makes its machining more convenient and practical.(4)Based on the comparison between finite element analysis of multiple parameters and the stiffness obtained from theoretical calculation,the modified stiffness coefficient was proposed to improve the stiffness calculation formula.The unbalanced response of the rotor was analyzed according to the modified stiffness,and the modified stiffness was compared with the actual rotor dynamic balance test to verify the rationality of the modified coefficient.