Thermodynamic rotary engine

A rotary engine which operates on a single-pass, constant pressure, thermodynamic process, which rotary engine comprises a rotary positive-displacement compressor for supplying continuous compressed air, a combustion chamber which is for receiving the compressed air from the compressor and in which a fuel is burned at substantially constant pressure, a rotary gas expander through which the products of combustion from the combustion chamber are passed for the purpose of the generation of useful mechanical power, and mechanical connector means by which the expander drives the compressor, the expander comprising a rotor which is mounted for rotation in a cylinder which is itself rotatable about an axis displaced from that of the rotor so as to create between the cylinder and the rotor a chamber, the volume of which chamber varies with rotation of the cylinder and the rotor, and an inwardly projecting vane fixed to the cylinder and slidably engaging in a pivotable sealing means in the rotor so as to divide the chamber whilst permitting engagement between the rotor and the cylinder throughout 360.degree. of rotation, and the expander having a fixed housing part containing inlet means for entry of the products of combustion to the chamber, which inlet means comprise a fixed first port in the housing part of the engine, which port is in communication with the combustion chamber, and a second port which rotates with and is located in one end face of the cylinder, and said expander also having outlet means for the products of combustion, which outlet means comprises an outlet port which communicates with the chamber and which is located in a circumferential face of the cylinder and rotates with the cylinder for the purpose of continuous passage of the exhaust gases to atmosphere.