Variable capacity scroll type fluid compressor

Abstract

A scroll type fluid compressor with a capacity adjusting mechanism is disclosed. The compressor includes a housing, a first fluid inlet port, a second fluid inlet port and a fluid outlet port. A fixed scroll member is disposed within the housing and has a circular end plate from which a first wrap extends. The end plate of the fixed scroll member partitions the inner chamber of the housing into a front chamber and a rear chamber. The rear chamber is divided into a discharge chamber connected to the fluid outlet port, a first suction chamber connected to the first fluid inlet port and a second suction chamber connected to the second fluid inlet port. An orbiting scroll member is disposed in the front chamber and also has a circular end plate from which a second wrap extends. Both wraps interfit at angular and radial offsets to form a plurality of line contacts to define at least one pair of sealed off fluid pockets. The end plate of the fixed scroll member has a hole at an outer peripheral portion thereof which connects the first suction chamber to the front chamber. The end plate also has a pair of holes which are placed at symmetrical positions and which connect the fluid pockets to the second suction chamber. Valve means is disposed in the communication line between the external fluid circuit and the connecting line of the first and second inlet ports to sectively control the connection therebetween.