Device comprising an expansion engine and a separate apparatus for feeding said engine

A device comprising an expansion engine, having at least one cylinder provided with at least one scavenge port and with a piston moving therein, a separate apparatus for feeding said expansion engine with combustion gases under pressure, said separate apparatus comprising a housing with a heat insulating liner, said housing being subdivided into a first and a second chamber by means of a partition, at least one burner being mounted in said partition to receive all air from said first chamber and, and in such a way that the combustion takes place in the second chamber, said first chamber being connected by a conduit to the cylinder of said expansion engine for supplying air under pressure by said expansion engine to said first chamber, a non return valve being provided in said conduit which opens due to the compression of the air during the return stroke of the piston, said first chamber acting as the only source of supply of air under pressure for said burner, means for controlling a continuous supply of fuel and air to said burner in such amounts that a substantially complete combustion of said fuel in said second chamber is obtained, said second chamber being connected by a conduit to the cylinder of the expansion engine, a controlled valve being provided in said conduit for supplying combustion gases to the cylinder of said expansion engine.