Rotary engine

A rotary engine comprising a housing, a drive shaft extending through the housing, a rotor coupled to the drive shaft, the rotor including a main body and a piston extending outwardly therefrom, the main body adapted to fit within the housing so as to form an annular chamber with the walls of the housing, the piston being movable within the annular chamber along a circular path and being shaped to fit closely to the walls of the annular chamber so as to provide a substantial seal without being prohibited from rotation, first and second cam assemblies mounted on the drive shaft on opposite sides externally of the housing, a door assembly operating to block and unblock the annular chamber, the door assembly actuated by synchronous rotation of the first and second cam assemblies such that the door assembly opens to unblock the annular chamber as the piston approaches the door assembly and closes to block the annular chamber after the piston has travelled past the door assembly, a temporary combustion chamber being formed between the door assembly and the piston as the piston moves away from the door assembly, a fluid inlet for providing a working fluid into the temporary combustion chamber, a fuel inlet for providing a fuel into the temporary combustion chamber, an ignition source, an exhaust path from the annular chamber, wherein, in use, the ignition source ignites a mixture of the fuel and the working fluid within the temporary combustion chamber and the explosion therefrom forces the piston along the circular path to thereby rotate the drive shaft, and wherein the piston releases pressure from the explosion within the chamber by uncovering an exhaust hole from the chamber into the exhaust path as the piston moves towards the door assembly but before the door assembly is reopened, means for thereby generating a single power stroke of the rotary engine coincident with the movement of the piston along the circular path starting from when the mixture is ignited and ending when the piston reaches the exhaust hole, and thus enabling the door assembly to reopen without frictional resistance due to pressure of the explosion within the chamber.