The present invention provides a system and method for economically using compressed air as automobile power source, comprising: a compressed air power device, which includes automobile air storage tubes (1) to store a sufficient amount of high-pressure compressed air and a cylinder-combined engine consisting of the first and second cylinders (9)(10), and which can make full use of the compressed air to produce driving power; a mechanism to produce, store and provide high-pressure compressed air, which includes a boiler-type high-pressure compressed air producing and storing device, abbreviated as boiler-type HCAPS device (4), to be able to use electricity during periods of low energy demand (off-peak) such as at night simultaneously recovering the by-produced heat for central heating, and pressurizing and inflating into the automobile air storage tubes (1) during daytimes; brake energy recovery and regeneration devices, which include a spring reserving-releasing device and/or a compressed air reserving-releasing device to save the compressed air in the automobile air storage tubes (1) for saving the driving power; an inner gear ring assembly, which includes an inner gear ring (2) gearing meshing with inner acting gears (45), with the first and second accelerating gears (72)(92), with a flywheel front inner meshing gear (48) and reset gears (46), for transmitting torque and mixing/outputting power; some clutch transmission devices and a controller, which controls orderly coordinated operation of devices and mechanisms.

A free piston device, comprises a housing with a cylindrical inner wall having a first wall opening and a second wall opening; a cylindrical piston movable in axial direction and rotatable around its longitudinal axis; the piston comprising a first skirt forming a first chamber, said first skirt having at least a first opening in the form of a hole through the wall of the skirt for allowing passage of a fluid directly into or out of said chamber; control means for controlling axial and angular movement of said piston; sensing means for providing signals related to the axial position and/or the angular position of the piston; a digital control unit for rotating the piston around its longitudinal axis in synchronism with its axial movement.

Various embodiments of the present invention are directed toward a linear combustion engine, comprising: a cylinder having a cylinder wall and a pair of ends, the cylinder including a combustion section disposed in a center portion of the cylinder, a pair of opposed piston assemblies adapted to move linearly within the cylinder, each piston assembly disposed on one side of the combustion section opposite the other piston assembly, each piston assembly including a spring rod and a piston comprising a solid front section adjacent the combustion section and a gas section; and a pair of linear electromagnetic machines adapted to directly convert kinetic energy of the piston assembly into electrical energy, and adapted to directly convert electrical energy into kinetic energy of the piston assembly for providing compression work during the compression stroke.

The present invention is a linear internal combustion free-piston engine with three acting pistons per combustion chamber, that has the ability to store energy until needed. This engine utilizes a spring to store potential energy after combustion. The present invention also introduces additional air into the combustion chamber during the combustion cycle providing a more complete burn of the fuel, has the ability to self-start, and does not idle. Multiple engines can be married together and run as a single unit.

In one embodiment, a power generation system includes a pulse detonation engine including a combustion chamber, a linear power generator including a working chamber, and a nozzle positioned between the combustion chamber and the working chamber that expands exhaust gas expelled from the combustion chamber, wherein the nozzle increases thermodynamic efficiency of the system.

A plunger pump or plunger motor includes a block accommodating a first cylindrical chamber and a plunger movable in this chamber and a drive shaft connected to this plunger, as well as a second cylindrical chamber and a control valve movable in this second cylindrical chamber. Holes O.sub.3 and O.sub.4 can alternately be brought into communication with the connection for the delivery pipe by the plunger and with a connecting hole for a pressure line. The control valve can establish a communication between the hole O.sub.2 and the connecting hole. The drive shaft is connected to a further plunger which is movable in a third cylindrical chamber in which there is a suction hole or delivery hole. The control valve can alternately establish a communication between the suction hole or delivery hole with a connecting hole for a suction pipe and the connecting hole for the pressure line.

A compressed-gas motor has a cylindrical inner chamber closed gas-tight at a first base surface, and a piston arranged so as to be movable along the cylinder axis in the cylindrical inner chamber. A first opening feeds a compressed gas into the inner chamber, and a second opening discharges a gas from inside the inner chamber. The openings are arranged in the cylinder casing of the cylindrical inner chamber, wherein the first opening is arranged between the second opening and the closed first base surface. The first opening is closable by a first piston part and the second opening by a second piston part. The compressed-gas motor has a resetting device which exerts a force on the piston in the direction of the first base surface of the cylindrical inner chamber if the second piston part does not completely close the second opening.

Various embodiments of the present invention are directed toward a linear combustion engine, comprising: a cylinder having a cylinder wall and a pair of ends, the cylinder including a combustion section disposed in a center portion of the cylinder; a pair of opposed piston assemblies adapted to move linearly within the cylinder, each piston assembly disposed on one side of the combustion section opposite the other piston assembly, each piston assembly including a spring rod and a piston comprising a solid front section adjacent the combustion section and a gas section; and a pair of linear electromagnetic machines adapted to directly convert kinetic energy of the piston assembly into electrical energy, and adapted to directly convert electrical energy into kinetic energy of the piston assembly for providing compression work during the compression stroke.

The present invention relates to a linear expander that can structurally offset vibration and noise caused from piston movement by moving pistons combined to two linear generators symmetrically provided in a body portion where a suction valve and a discharge valve are respectively provided to bilaterally opposite directions, and accordingly the expander has a simple structure and motion stability of the compressor can be improved.

Various embodiments of the present invention are directed toward a linear generator, comprising: a cylinder having a cylinder wall and a pair of ends, the cylinder including a reaction section disposed in a center portion of the cylinder; a pair of opposed piston assemblies adapted to move linearly within the cylinder, each piston assembly disposed on one side of the reaction section opposite the other piston assembly, each piston assembly including a spring rod and a piston comprising a solid front section adjacent the reaction section and a gas section; and a pair of linear electromagnetic machines adapted to directly convert kinetic energy of the piston assembly into electrical energy, and adapted to directly convert electrical energy into kinetic energy of the piston assembly for providing compression work during the compression stroke.