The Finite Element Analysis On Scrolls Of New Oil-free Scroll Compressor

At present, food, medical, electric cars, and other areas of the industry need clean and oil-free compressed gas. As the fourth generation of the most advanced displacement fluid machinery, oil-free scroll compressor has many advantages such as high efficiency, low noise, simple structure, reliable, energy saving, and widely used in above fields. In order to understand the deformation rule of scrolls and improve the efficiency of scroll compressor, the finite element analysis is applied to anlyse the deformation of scrolls under the actual working conditions. The main research contents are as follows.(1)Based on the geometry theory of scroll profile, the volumes of the working chambers are calculated with respect to the orbiting angle from the suction to the discharge process. The gas forces and moments acting on the orbiting scroll are calculated with respect to the orbiting angle. Working principle of self lubricating sealing mechanism of oil-free scroll compressor is illustrated(2)The temperature and pressure of each chamber are measured through arranging temperature and pressure sensors in the back of the fixed scroll. The measured temperature and pressure are the input conditions of finite element analysis. The thermal analysis, structure analysis and physical field coupling analysis of orbiting scroll were analysed, the analysis results indicated that the maximum deformation of scrolls is located on the head, the maximum deformation of coupling field was 0.169 mm. The control variate method is applied to analyse the scrolls of prototype for different parameters including the hight and thickness of scrolls. The compared results indicated that the deformation of scrolls increases with increasing the height and the deformation of scrolls decreases with increasing the thickness.(3)The orbiting and fixed scrolls are assembled in Solidworks. The finite element method is applied to analyse the assembled scrolls under different axial and radial clearance. The best assembly clearance of the prototype is obtained, the axial gap and radial gap are 5μm and 20μm, respectively. The deformation of fixed scroll was analysed with the different position and number of pin. The test rig for 0.6m3/min oil-free scroll compressor is developed and the performance is tested.