Abstract: A pure rotary positive displacement device includes a rotatably mounted circular cylindrical housing having an even number of equiangularly spaced, radial cylinders formed therein. A rotatably mounted piston carrier rotates in synchronization with the cylinder housing and supports at least one piston for movement within the cylinders. The central axis of the piston carrier is offset from the central axis of the cylinder housing, and each piston is spaced from the central axis of the piston carrier by the offset between the rotational axes of the piston carrier and the cylinder housing. The pistons and cylinders preferably have congruent conjugate surfaces to reduce leakage between the pistons and the cylinders, and the pistons are rotatably mounted to the piston carrier. The number of pistons is typically one-half the number of cylinders, and if multiple pistons are used, then they are spaced equiangularly about the piston carrier.

Abstract: The disclosure relates to a rotary machine, the basic elements of which are generically adapted for use as a two-stage pneumatic compressor or as a four-cycle combustion engine or as a two-cycle combustion engine. The basic combination of elements of the machine comprises a plurality of rotors rotatably mounted on axes disposed at substantially right angles to each other and wherein the rotors are provided with peripheral portions having inwardly notched or recessed chamber portions which are disposed between alternate radially extending lobe portions.