Multi-stage scroll compressor

Abstract

A scroll is provided which can be operated as either a vacuum pump, a low pressure compressor or a high pressure compressor. The scroll includes a housing, a fixed scroll plate having a continuous fixed involute wrap and an orbiting scroll plate having a continuous orbiting involute wrap. The wraps are of constant width and pitch. The fixed and orbiting scroll plates are mounted in the housing with their involute wraps extending toward each other to define a series of chambers. The fixed involute wrap and orbiting involute wrap each have at least a first section of one height and a second section of a second different height. Additionally, the scroll includes a first port proximate a peripheral edge of the housing, a second port proximate the center of the housing, and at least one mid-port; the mid-port being located proximate the change in height between the first and second sections of the involute wraps.

Dependencies are inferred from the claim text.