A Study of Oval Scroll Compressors for Stroke Volume Increase

Abstract

In recent years, there has been demand for a large-capacity scroll compressor to reduce the size and increase the output power. To increase the capacity of the scroll compressor, technology to increase the stroke volume without increasing the shell size is required. To increase the stroke volume, increasing the wrap height in the axial direction is most effective. However, the higher wrap height raises the stress on the wrap and causes the orbiting scroll to overturn. So, we started to study a new shape of wrap to increase the stroke volume in the horizontal direction. The base plate of an orbiting scroll is usually circular. However, the shape of the sliding surface of the fixed scroll on the base plate of the orbiting scroll is not circular, so wasted space that is not useful for compression exists on the base plate. We devised an oval wrap to make the trajectory of the fixed scroll on the base plate circular and reduce this space. Oval scrolls can increase the stroke volume by 20% compared with the conventional scroll under the conditions evaluated in this paper.