Rotor for a rotary engine

An air cooled rotor in a rotary internal combustion engine of the kind comprising a cavity, means for mounting the rotor in the cavity for rotation, the walls of the cavity being shaped to provide walls of working chambers formed by the rotating rotor, the working chambers varying in volume as the rotor rotates, the engine having inlet and outlet ports to the cavity, the rotor comprising a body having, in a plane transverse to the axis of rotation of the rotor, an outer profile of generally equilateral triangular shape with outwardly curved sides and an inner profile providing part peripheral location portions in the regions of the mid point of the rotor sides, an insert in engagement with the part peripheral location portions, the insert providing a bearing part and an indexing gear of the rotor, the inner profile of the body adjacent each apex of the rotor, being radially outwards of the insert over the entire axial length of the body, thereby providing gaps between the location portions to provide axial cooling passages, peripherally bounded by the rotor body and the insert, which extend continuously over the entire axial length of the body, and the engine having means to pass cooling air axially through said axial cooling passages from one end of the body to the other end thereof.