THERMAL ENGINE, ESPECIALLY PISTON ENGINE

A thermal engine operating according to the Stirling process, particularly a piston engine which includes at least one hot gas section and one cold gas section between which a gaseous working medium is interchangeable by way of a regenerator. The working medium is heated directly in the hot gas section by the feed and combustion of fuel while the combusted working medium is at least partially replaced at the cold gas section by fresh working medium. An exhaust gas turbo-charger may be utilized for supercharging the fresh working medium. The engine is constructed so that fresh working medium is introduced during the transition from the expansion to compression of the cold gas section with a delay in the introduction of the fresh medium until late in the expansion phase. Either a rotary piston arrangement or an engine with axially reciprocating pistons may be used with both arrangements using piston controlled slot openings for admission of the fresh medium and exhaust of part of the medium. In the axially reciprocating piston arrangement, the piston of the hot gas section is axially aligned in a common housing with the piston of the cold gas section and with the regenerator arranged in the housing between said pistons.