Scroll type compressor with displacement adjusting mechanism

Abstract

A scroll type compressor including a housing, a fixed scroll which is joined to the housing and including a first end plate from which a first wrap extends and an orbiting scroll which includes a second end plate from which a second wrap extends. The wraps interfit at an angular and radial offset to make a plurality of line contacts to define at least one pair of sealed off fluid pockets. The first end plate is formed with a plurality of pairs of holes, the holes of each pair of holes being placed at symmetrical positions. The most inwardly placed hole is placed at a location defined by involute angles within the area defined by .phi.end-2(n-1).pi.>.phi.1>.phi.end-2n , where .phi.end is the final involute angle of the wrap which extends from the end plate having the holes, .phi.1 is the involute angle at which the hole is placed and n is the amount of pairs of holes. The most outwardly placed hole is placed at a location defined by involute angles within the area defined by .phi.n-1+2.pi.>.phi.n>.phi.end-2.pi.. The intermediate holes are located within an area defined by .phi.k-1+2.pi.>.phi.k>.phi.k+1-2.pi., where .phi.k is the involute angle at which hole kth from the most inwardly placed hole is located. A control mechanism controls the opening and closing of the holes to thereby control the capacity or displacement volume of the compressor.