Abstract: A free piston engine wherein a combustion piston directly drives a pumping piston to pump hydraulic fluid to and fro to a linear to rotary motion pump/motor converter which is in the form of a "split cycle" machine.

Abstract: A machine that converts between reciprocating motion of a piston and rotary motion of a shaft. The shaft rotates an integral web that carries a number of lobe wheels spaced evenly about a pitch circle centered on the shaft. The lobe wheels are planetary driven by pinions and a fixed ring gear. The lobe wheels are somewhat star shaped with radially extending lobes which push followers outwardly, then release them inwardly, as the lobe wheels orbit past and below the follower. The follower is connected by a lever and a pair of connecting rods and to the piston.

Abstract: A radial cylinder machine comprises a number of equispaced lobed shafts (7) which orbit about the central machine axis inwardly of the pistons (13). The lobed shafts (70) also rotate about their individual axes by virtue of planetary pinions on each shaft (7) meshing with a fixed ring gear. The orbiting and rotating lobes (9) act as cams on the inward faces of the pistons (13) whereby there is inter-conversion of reciprocatory motion of the pistons (13) and rotary motion of the lobed shafts (7). The lobed shafts (7) are mounted on a carrier fixed to a central axis input/output shaft whereby torque may be transferred permitting the machine to act as an engine or pump. There is also disclosed a means of maintaining contact between the pistons (13) and the lobes (9).