Dynamic model for the orbiting scroll based on the pressures in scroll chambers–Part I: Analytical modeling

This two-part work proposes a dynamic model for the orbiting scroll based on the pressures in the scroll chambers. In Part I, the scroll mechanism and characteristic polygon of the scroll compressor are defined, the geometry of the multi-wrap compressor is described, the modification and construction methods for one multi-wrap scroll are presented, and the dynamic model is developed. Thereafter, the overturning moment and theoretical driving power of the scroll mechanism are discussed. This dynamic model can predict the pressure distribution on wrap surfaces as well as the variations of the axial force, tangential force, radial force, overturning moment, self-rotation moment, and resistance moment. This dynamic model provides better understanding of scroll compressors and other types of scroll machines. The investigations on scroll compressors using this model and the model verification are reported in Part II.