Abstract: A rotary engine is provided. The engine has a main body that fits within a housing to form an annular chamber. A piston moves within the annular chamber along an annular path. A door assembly operates to block and unblock the annular chamber, opening to unblock the chamber as the piston approaches the door and closes to block the chamber after the piston has travelled past the door. A temporary combustion chamber is formed between the closed door and the piston as the piston moves away from the door.

Abstract: The problems of prior compressor structures relying upon conventional check valves are obviated by using, instead, flow control passages which operate to control flow while avoiding mechanical moving elements which may become problematical.

Abstract: A motor, expander, compressor, or hydraulic device is formed with an oscillating rotating piston comprising a cylinder having an axis of rotation and end surfaces and defining an oscillating compression volume and an expansion volume. An axial sealing member separates the compression volume and the expansion volume, and seal members seal the end surfaces of the piston. Valves operate to close the compression volume and open the expansion volume at each oscillation of the piston. Means are provided for reversing the rotation of the cylinder at the end of a compression cycle of the piston. One or more pistons may be provided that contact other pistons along axial surfaces to form axial seal surfaces with rolling contacts that reduce friction energy losses.

Abstract: A reversible rotary internal combustion engine comprising a stator which defines a cylindrical chamber (43), a drive shaft (1) extending coaxially through the chamber, a rotor (2) comprising a cylindrical hub mounted coaxially on the drive shaft and a rotor arm (3) extending radially from the hub, two radially movable wall members (4a, 4b) mounted in the stator, each of the wall members having a retracted position in which the radially inner face of the wall member lies flush with the inner periphery of the stator and an inserted position in which the face of the wall member is in contact with the peripheral surface of the hub, means (8a, 8b) for selecting one of the wall members (4a, 4b) to lie normally in the inserted position so as to divide the chamber (43) into a combustion chamber (47) between such wall member and the rotor arm (3) and an air compression chamber (48), means (12, 13) for introducing air and a fuel into the combustion chamber (47) whereby upon ignition of the fuel/air mixture the combusti