Abstract: A wobble plate compressor including a three-part housing in the form of a front shell-like section, defining a wobble plate mechanism cavity, an intermediate cylinder block section and a rear head section, all of the parts being connected in series such as by elongated cap screws. A blind bore in the first section end cover receives a piston to define an expansible chamber actuator. Passage means are formed in the housing for conducting hydraulic fluid from the housing sump to the inlet of pump means. Hydraulic liquid outlet passage means, providing a flow passage between the front and rear heads, are formed in the housing such that control valve means in the rear head can affect the flow of the liquid or oil from the sump to the expansible chamber, causing the modulating piston to vary the angle of the wobble plate mechanism and thus the pumping capacity of the compressor.

Abstract: A swash plate radial piston compressor having a toggle action connection means between the swash plate and pistons wherein each piston makes two reciprocations in its cylinder for each 360.degree. of rotation of the compressor input shaft. Means are provided for varying the angle of the swash plate such that a nutating ring, which encircles the swash plate in journaled fashion around the periphery of the swash plate will vary the length of the stroke of the pistons upon a change in the angular position of the swash plate causing a change of volume displacement of the compressor without changing the head clearance of the radial pistons, thus allowing the compressor to go to zero displacement while the input shaft continues to rotate.