Abstract: An engine (5) with a gas supply unit (10) that supplies combustion gas for driving purposes with linear reciprocal movement of a piston (12) is provided. The gas supply unit (10) includes a first combustion chamber (31) provided on a first side of the piston, a first gas outlet (17) that supplies high pressure combustion gas generated in the first combustion chamber for driving purposes, and a second combustion chamber (32) that is provided on a second side on the other side of the piston and generates a second force that moves the piston toward the first side. The engine (5) further includes a piston control unit (60) that controls the position of the piston against a first force of the piston that moves due to combustion in the first combustion chamber and the second force described above.

Abstract: There is provided an engine (10) including a gas turbine unit and a plurality of combustion units (80) that supplies combustion gas (51) to the gas turbine unit. Each of the combustion units (80) includes: a combustion chamber (11); a first mechanism (71) that moves a first wall surface (81a) that configures a part of the combustion chamber, using an elastic force of a spring (83) to reduce a volume of the combustion chamber (11) and pressurize a gas (58) inside the combustion chamber; and a second mechanism (72) that opens and closes an exhaust port (85) of the combustion chamber to control the timing at which combustion gas (51) is discharged from the exhaust port.

Abstract: An engine (10) that jets out combustion gas as a driving force is provided. The engine (10) includes a combustion chamber (11), a fuel supplying path (13) that mixes fuel and air and supplies to the combustion chamber (11), an igniter (42) that ignites the mixed gas in the combustion chamber (11), a gas ejecting path (15) that ejects combustion gas (51) from the combustion chamber (11) though a nozzle (18a); and an opening-closing apparatus (80) that opens and closes the gas ejecting path (15). The gas ejecting path (15) is opened by the opening-closing apparatus (80) immediately before ignition, simultaneously with ignition, or immediately after ignition.