Combustion engine

The internal combustion engine has a piston rod (6), which is connected at both ends with respective piston-cylinder units (3,4,17,18). A coupling part (7) is arranged on the rotor (10) having a rotor or driving shaft (9). The conversion elements (8,22) are provided for converting the reciprocating motion of the piston rod and the coupling part into a rotational movement the rotor and the rotor shaft.