Patent ID: 8201407

Claim:
A drive unit comprising: a reciprocating piston expansion engine, the reciprocating piston expansion engine comprising: at least two cylinders; a piston arranged in each of the cylinders; a supply for each of the at least two cylinders configured to provide a fluid in at least one of a vaporous and gaseous form; an inlet valve for each of the at least two cylinders, the inlet valve having an open state configured to provide the fluid from the supply to an interior of a respective one of the at least two cylinders and a closed state configured not to provide the fluid from the supply to the interior of the respective one of the at least two cylinders; at least one bypass valve arranged in parallel to a respective one of the inlet valves, the at least one bypass valve configured to provide the fluid from the supply to the interior of the respective one of the at least two cylinders in an open state; and a crankshaft to which each of the pistons is coupled; a combustion engine, the combustion engine comprising a driven shaft; and a freewheel coupled to the crankshaft configured to transmit torque to the driven shaft.