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.