Abstract: The present invention provides improved alternators for use alone or in combination with, for example, rotary internal combustion engines wherein the alternators are characterised by absence of moveable bearings or mountability to existing driving shafts by use of an aligning plate and through passage through the rotor of the alternator to mount to the driving shaft. The alternators may be further characterised by plural rotors on the rotor driving shaft. The rotary internal combustion engines of the present invention are characterised by fixed size combustion chambers formed of radial recesses around a rotor amongst other features.