Patent ID: 8528505

Claim:
A rotary internal combustion engine comprising: a cylinder having a cylinder circumferential wall provided with a horizontal valve groove on an inner circumferential surface thereof; a working shaft concentrically run through said cylinder and held to be freely rotatable; a rotor which includes a rotor base made of a circular shell, a rotor base surrounding wall, and a rotor blade standing in a radial direction of the rotor base surrounding wall, and which is firmly fixed to said working shaft; a shutoff valve which performs intermittent movements of insertion and returning between an outside of said cylinder and a cylinder space defined inside the cylinder; and left and right side lids each having one of two longitudinal valve grooves, wherein, in a manner to be timed to the insertion of said shutoff valve into said cylinder space, a radial distance in a circular rotation angle region of said rotor base is shortened by an interference prevention distance so that said rotor base surrounding wall has a cam-like shape; in the cylinder space, both side faces of said rotor base and all outer edge portions of said rotor blade are hermetically in contact with left and right inner walls of the cylinder and the cylinder circumferential wall; when the insertion of said shutoff valve into the cylinder space is completed, both ends of said shutoff valve are hermetically held by the two longitudinal valve grooves formed in the left and right side lids respectively, an upper portion of said shutoff valve is hermetically held by the horizontal valve groove formed in said cylinder circumferential wall and a lower end surface of said shutoff valve is hermetically in contact with said rotor base circumferential wall to form a sliding face of said rotor base; immediately after passing of said rotor blade through a position of said shutoff valve, said shutoff valve is inserted into said cylinder space to stop up said cylinder space in a radial direction, and compressed mixed air, or compressed air and fuel is/are injected into a sealed layer, which serves as a combustion chamber and which is defined between said shutoff valve and said rotor blade, to be ignited or fired in the combustion chamber, and further said rotor blade is pressed with combustion expansion pressure, with said shutoff valve as a base point for a mechanical action, to directly provide rotation to said working shaft, and combustion gas is released through an exhaust hole and said shutoff valve is returned back to an outside of said cylinder for preparation of a next stroke to terminate one working stroke.