Study on basic parameters of scroll fluid machine based on general profile

Based on general profile theory, the basic scroll profiles are presented in the form of polynomial or simple trigonometric functions. For a scroll fluid machine with an arbitrary number of scroll wraps on its individual scroll, the phase difference between adjacent scroll profiles is defined as the characteristic angle and its scroll pitch lines are classified into A-type and B-type. The normal thickness and the all-thickness of scroll wrap are also defined. The number of scroll wraps on one scroll, the orbiting radius, the maximum tangential component of general profile, the thickness coefficient, and the height of scroll wrap are determined as the basic parameters which can demonstrate basic characteristics of scroll fluid machine. It is more reasonable to employ involute of circle and double-wrap scroll, to specify a smaller orbiting radius and a smaller height under satisfaction of the basic requirement. According to the basic parameters proposed, scroll fluid machine is classified into small-parameter and large-parameter scroll fluid machines. In order to obtain the performance with higher working pressure and larger compression ratio, it may be a significant work to study the large-parameter scroll fluid machine.