Finite Element Analysis Of Orbiting Scroll Of Scroll Compressor Based On Thermal Stress Field Coupling

Scroll compressor is a widely used form of energy-saving type fluid machinery, with the advantages of high performance, light weight, small vibration and high reliability. The aim of this thesis was to numerically simulate the flow field of scroll compressor in working to obtain the temperature distribution, and the vortex flow field was loaded as boundary condition of wraps. The stress and deformation in scroll under the action of gas pressure, temperature load and both of them was analyzed, and the stress distribution and deformation of wraps in different shaft rotation angles was discussed, it also respectively obtained the stress distribution and deformation discipline of wraps. Natural mod of scroll was analyzed, and the natural frequencies and mode shapes were got. Also, the fatigue life was predicted based on the results of finite element structural analysis, the life distribution and the minimum fatigue life of orbiting scroll were got. The main work was as follows:(1)According to current research and theory of scroll compressor, we studied the basic structure, the working principle, line geometry theory and the force on orbiting scroll was analyzed,including the basic equations of lines, the basic parameters of scroll wrap, the calculation of the working chamber volume and the calculation of load.(2)The finite element model of the orbiting scroll of a scroll compressor based on the thermal stress coupled field was established, the stress distribution and deformation of wraps in different shaft rotation angles was discussed, it also respectively obtained the stress distribution and deformation discipline of wraps. The results show that the overall stress and deformation in scroll are the largest when compression chamber is moving near the vent position; the head and the end of the vortex gear is dangerous. Thermal deformation is the main factor of affecting the overall deformation of scroll. The reliability on finite element simulation was analyzed, verify the reasonableness of the analysis method and the reliability of the results.(3)Analysis modal of the orbiting scroll was to get the natural frequency and vibration mode. The results show that the rotary vibration frequency of the scroll compressor is one-third lower than orbiting scroll modal. rotary percussive frequency is not in the range of natural frequency of orbiting scroll, it will not produce resonance. Modal analysis provide basis for structural dynamics analysis and structure improvement of design and laid the ground work for later compressor design.(4)According to the working conditions and material properties of the orbiting scroll, select the s- n curve and a reasonable correction parameters, use the previously obtained results of structural static analysis and impose reasonable fatigue loads is to analysis the fatigue and forecast the fatigue life. The result shows that the orbiting scroll can meet the requirement of minimum fatigue life; it has a guiding meaning and application value.