Research On Structure Optimization Design Of The Involute Scroll Compressor

As a kind of precise and efficient volumetric fluid machinery,scroll compressor is widely used in mining machinery,medical and health care,air conditioning refrigeration,engine pressurization and other fields.Medium and large scroll compressors often have many problems such as low utilization rate of scroll plate area,poor reliability,sealing fault,and serious wear.To obtain a scroll air compressor with good geometric performance,mechanical properties of scroll teeth,and good sealing conditions,the parameters of the involute scroll profile were systematically optimized in this paper,by establishing the structure model of the scroll compressor,the kinematic performance,the modal shape of the rotor system,the flow field characteristics in the compression chamber and the stress and deformation of the scroll teeth were analyzed.The operation of the scroll compressor was verified by design experiment,and the tribological performance between the orbiting scroll,the Oldham’s coupling,and the fixed scroll were explored,which provides a reference for the optimization design of scroll compressor.The specific work content of this paper is as follows:1.Aiming at the problems of low utilization rate of scroll plate and poor mechanical properties of scroll teeth in scroll compressor profile design,the influence of parameters of base circular involute scroll compressors on geometric properties and mechanical properties of scroll teeth was investigated.The optimal profile parameter combination within a certain range was obtained by orthogonal test considering the stroke volume and mechanical properties of scroll teeth.The vortex profile was further optimized by genetic algorithm toolbox,so the optimal profile parameters of the existing scroll blank were obtained,and the optimal profile parameters were used to model the scroll disk.2.In order to analyze the operation characteristics of scroll compressor parts and test the meshing of orbiting and fixed scroll teeth,the dynamic balance design of the scroll compressor rotor system was carried out,and the virtual prototype model of the simplified model of scroll compressor was established.The kinematics characteristics of the main moving parts and the first six modes and natural frequencies of the rotor system were analyzed,the working reliability of rotor system was tested.3.In order to obtain the variation of flow field in compression chamber of scroll compressor,based on the ANSYS Workbench platform,the flow field simulation analysis of the fluid domain grid model of the scroll compressor at different speeds was carried out.The changes of pressure and temperature in the compression chamber with the crank angle and the motor speed were explored.According to the simulation results of the flow field,the pressure and temperature transient load in the compression chamber at the highest motor speed was selected to carry out the fluid-heat-solid multi-field coupling analysis on the scroll disk,and the mechanical properties of the scroll teeth were checked.4.In order to test the actual working performance of scroll compressor,a scroll compressor test platform was built to test the compressor discharge.Aiming at the wear problem between the Oldham’s coupling and the orbiting scroll,the main force of the keyway of orbiting scroll on the convex key of Oldham’s coupling was calculated.Based on this,the friction and wear test of the orbiting scroll and Oldham’s coupling material was carried out,and the wear rate of the convex key material of Oldham’s coupling was obtained.The pollutant filter device at the compressor exhaust was designed to reduce the damage of the wear particles in the compression chamber to the subsequent working parts.The copper powder filled PTFE was used to make the seal strip,and its wear performance to scroll disk material was investigated,which provided a new idea for the study of tribological properties of the scroll compressor.