A study of planar orbiting mechanism and its applications to scroll fluid machinery

Abstract

The law of gearing plays a very important role in the mechanism and machine design. On the contrary to a gear which usually rotates about its own axis without translational motion, the planar orbiting mechanism moving around a circular orbit without self-rotation is also an important mechanism. It has the ability of changing its enclosed fluid volume and therefore can be applied to fluid machines such as pumps, compressors and engines. In this paper, some elementary theorems related to the design of planar orbiting mechanisms are proposed and proved. Applications based on these thethese theorems are discussed. Two examples in the design of scroll fluid machines are particularly illustrated; one of which focuses on the geometric scroll shape design and the other points out a way to construct the so-called perfectly meshing scroll profiles.