Study On Scroll Compressor Teeth Deformation Under Multi-load Coupling

Scroll compressor is a new positive-displacement compressor. As the pressure and temperature increase during the gas compression process, thus leads to thermal and force deformation of the scroll plates. The deformation result in the meshing place clearance variation between orbiting and fixed scroll plates. If the clearance is too large, more compressed media will leak and the performance of compressor will drop. If the clearance is too small, wear between scroll plates will increase. Therefore,the study on deformation and clearance of scroll plates has an important significance to improve the performance of scroll compressor. In this paper, with the method finite element analysis software, the scroll teeth deformation with different materials and different thickness are to be analyzed to acquire the scroll teeth deformation under different loads, then achieve the variation rules of axial clearance and radial clearance.Based on the circular involutes and thermodynamics theories to obtain the calculation foundation of gas forces and gas temperatures, take this as the border condition to acquire the scroll teeth deformation under force/thermal/coupling loads with the usage of finite element analysis method.Through the analysis on three kinds of materials deformation: cast iron,cast copper and cast aluminum, study shows: Cast iron scroll plate has the smallest deformation under coupling effect, then is copper,aluminum has the largest deformation; There is a large difference in deformation of scroll teeth under force and thermal loads, cast iron has similar maximum deformation under these two kinds of loads, copper and aluminum take a larger deformation under thermal load than force load. For scroll teeth with different thickness under thermal/force loads and coupling effect, the thicker scroll teeth is, the smaller deformation it has. Teeth head has the largest deformation difference. As the increase of spread angle, the deformation difference decreases. In comparison with radial deformation, the influence of thickness to axial deformation is more remarkable.Under force/thermal loads and coupling effect, scroll teeth in cast iron has the smallest clearance, then copper, clearance of aluminum scroll teeth is the largest. The increase of all spread angles radial clearances inner orbiting scroll plates will lead to the raise of leakage; from the center discharge chamber to outside, the radial clearance of first compression chamber within fixed scroll plate increases comparatively larger,variation of chambers outsides decrease slightly. The axial clearance of firstcompression chamber at the top of scroll teeth decreases, whereas other chambers increase.This paper has achieved the deformation laws and leakage clearance of scroll teeth under multi-load effect, perfect the materials and teeth thickness and provide theoretical guidance and technical support to scroll teeth design to a certain extent.