Scroll type compressor having a counterweight mounted with a clearance

Abstract

The scroll type compressor includes a stationary and orbiting scroll members, of which the spiral elements are interfit at an offset angle to form line contacts defining at least one fluid pocket, and an anti-spin mechanism for causing the orbiting member to orbit within the stationary member. A drive shaft is rotatably supported in a housing, and has an outer end a cylindrical inner end and, depending upon the embodiment, either a crank pin or a sliding guide portion projecting axially inward from its inner end. A drive bush couples the drive shaft to the orbiting scroll member, and has either a circular aperture for receiving the crank pin or an engaging slotted recess for receiving the sliding guide portion, as the case may be, whereby the drive bush is either pivotable or slidable with respect to the drive shaft. A counterweight is mounted on either the crank pin or the sliding guide portion between the drive bush and the drive shaft, and is coupled to the drive bush for conjoint movement therewith. The counterweight has a cylindrical recess for receiving the cylindrical inner end of the drive shaft, with a clearance maintained between the radially inner perimeter of the recess and the radially outer perimeter of the inner end of the drive shaft, so as to allow the drive bush and counterweight either to pivot relative to the crank pin or to slide relative to the sliding guide portion, depending upon the embodiment.