Abstract: A rotary internal combustion engine (200) of the type having a rotor assembly (216) supported in a housing (210) for rotation about a longitudinal axis (217), the housing having two spaced apart end plates (212, 213) and the axis being the axis of rotation of an output shaft (218) operatively connected at one end to the rotor assembly, the other end being free and passing through an aperture in one of the end plates, the rotor assembly including a plurality of pistons (231 to 238) mounted for reciprocating movement in respective cylinders (228) arranged in spaced relation around the longitudinal axis, and cam follower means (254) operatively connected to each piston and adapted to coact with undulating cam track means (225) supported around the axis of rotation and between the end plates, characterized in that the undulating cam track means includes an annular track mounted to a support stem or shaft (219) disposed substantially centrally thereof and extending in the direction of the longitudinal axis, the su

Abstract: A rotary internal combustion engine of the type having pistons mounted for reciprocatory movement in respective cylinders which are arranged in equally-spaced relationship around a longitudinal axis of rotation, said axis being the axis of rotation of an output shaft passing rotatably and sealably through apertures of respective first and second end plates of a housing within which the pistons and cylinders move as part of a rotatable rotor assembly secured to said output shaft, while the pistons are simultaneously movable reciprocably in the cylinders, cam follower means being associated with each piston and adapted to coact with undulating cam track means around the housing. Cyclical combustion of fuel in the cylinders imparts reciprocation to the pistons with resultant thrust against the cam track means so as to cause rotation of the rotor assembly and output shaft.