Abstract: A unitary, “hollow out” piston is molded or forged with only two tools, which move along a single parting direction, with a pair of arcuate side walls that provide maximal outer surface area with minimal thickness and weight. The thin walls are internally fortified by a cruciform support structure that is molded integrally by the same tools. No post forming machining steps are needed to reduce weight.

Abstract: A compressor of the present invention includes a drive shaft extending along a longitudinal axis, a swash plate assembly operatively connected to and driven by the drive shaft, a retainer ring for disposition about the drive shaft. The drive shaft has first and second annular grooves therein and spaced longitudinally from one another and a conical ramp extending out of the first annular groove toward the second annular groove for facilitating movement of the retainer ring out of the first annular groove and along the drive shaft to the second annular groove. The swash plate assembly includes a journal member connected to a drive hub further connected to the drive shaft and is rotated thereby with the drive shaft around the longitudinal axis to form the inclination angle of a swash plate thereby controlling displacement of the swash plate assembly.