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 combustion gases exert a force on the rotor arm (3) to rotate the rotor (2) in a predetermined direction according to which wall member (4a, 4b) is selected, and timing means sychronized with the rotation of the rotor (2) to retract the selected normally inserted wall member (4a, 4b) for a period of time sufficient to allow the rotating rotor arm (3) to move the space occupied by the selected wall member when inserted and then to reinsert such wall member.