The machine combination of an internal combustion engine and the generator of a hybrid drive has two cylinder-piston units, which are arranged parallel to each other in a common housing and each piston of which has a drive connection to an individual crankshaft via connecting rods associated with the pistons. The crankshafts have a counter-rotational connection to each other by gears. This coupling of the two crankshafts by gears allows the internal combustion engine to be combined with a generator in a particularly compact design, in that the shaft of the generator bears a gear, which is arranged in the same plane as the gears of the crankshafts.