Geometric design and analysis of scroll compressors with a novel circular involute modified wrap

The scroll geometry in the central region of the scroll wrap plays a crucial role in determining the working performance of scroll compressors. In order to improve the comprehensive performance of scroll wraps, in this study, a novel circular involute modified wrap was put forward, in which the central and peripheral wrap profiles were connected by a circular involute in the central regions, so that a pair of fully smooth and correct meshing scroll wraps were generated. A geometric model of the involute modified wrap were proposed, and then equations of the wrap profiles and relations between geometric parameters were derived. Effects of geometric parameters on the shape and performance of the involute modified wrap were discussed in detail. Furthermore, the compression ratio of the involute modified wrap was studied by numerical simulation, and the deformation of the involute modified wrap produced by temperature load and pressure load was calculated, compared with the conventional circular arc modified wrap under the same geometric shape of scroll compressors. Study results demonstrate that the proposed involute modified wrap may simultaneously improve the compression ratio and the strength of wrap head for scroll compressors; in addition, the involute modified wrap is good for design flexibility, and therefore is superior to the circular arc modified wrap.