Abstract: A free-piston engine comprises a combustion part (1), a hydraulic control system (2), an energy consumption system and an engine control system. The combustion part comprises a combustion cylinder with at least one combustion piston (4). The hydraulic control system (2) comprises a hydraulic piston (24) which, together with a combustion piston (4), forms a piston assembly, and which has a first surface that, when under hydraulic pressure, exerts a force on the piston assembly (24) that is directed towards the combustion space (6) and a second surface, smaller than the first surface, that, when under hydraulic pressure, exerts a force on the piston assembly that is directed away from the combustion space.

Abstract: AN external-combustion gas turbine in which the fuel combustion takes place in a free-piston combustor. The gas turbine is the motor component of this type of engine and provides external power by means of its shaft. The gas turbine comprises an air compressor and a combusted gas expander both mounted on that same shaft. The compressed air output is directed to a storage-tank and heat-exchanger combination. The air is then admitted in the valve-less free-piston combustor and further compressed. Fuel is burned therein which further raises the pressure of the combusted gas resulting therefrom. The combusted gas is then directed to the storage tank where it exchanges some of its heat content with the compressed air. The combusted gas is then ducted into the turbine inlet and expands therein, providing energy to drive the compressor and yield shaft power.

Abstract: An internal combustion engine comprises a cylinder and a piston axially movable within the cylinder and formed with cylindrical projections extending axially outwardly from the piston and being of a smaller diameter than that of the piston. The piston and its projections are formed with ducts which are connectable with inlet ports formed in the wall of the cylinder for admitting air and/or air/fuel mixture into combustion chambers of the engine and outlet ports for expelling exhaust gases from the combustion chambers, upon the movement of the piston. The ducts are formed one each within one of two longitudinal piston halves. The inlet ports, outlet ports and ducts are assigned to two longitudinal halves of the piston and its projections and arranged in the engine so that the admission of air and/or air/fuel mixture into the combustion chambers and the removal of exhaust gases therefrom via short, low-turbulence paths are controlled only by the position of the piston and its projections within the cylinder.

Abstract: A method and device for driving a linearly movable component, wherein a pressurized fluid is generated by feeding a given volume of oxygen into a combustion space connected to a piston/cylinder configuration and feeding a given volume of fuel into the combustion space for each motion stroke of the piston/cylinder configuration beore the start of the motion stroke, the given volume of oxygen is sufficient for the combustion of the fuel, the given volume of fuel is sufficient for generating the pressurized fluid, the oxygen and fuel are ignited in the combustion space, and the pressurized fluid is feed into the piston/cylinder configuration for driving a piston of the piston/cylinder configuration and a linearly movable component connected to the piston.

Abstract: A free piston combustion chamber coupled to air compression and gas expansion chambers are combined with a rotary motor. The rotary motor shaft drives the air compressor, receives power from the expanding gases in the expansion chamber and provides residual torque and power for external use. Two combustion chambers located at each end of the free piston receive compressed air and fuel for combustion outside of the rotary motor assembly. The motion of the free piston between the two combustion chambers is independent of the motor rotary motion. The air admission inside the combustion chambers, the fuel injection and the combustion initiation process are all controlled and timed by the free piston movement back and forth. A heat exchanger is located between the combustion-chamber/free-piston assembly and the rotary motor. The compressed air exiting from the compression chamber is heated by the gases exiting from the combustion chambers, before they are admitted into the expansion chamber of the rotary motor.

Abstract: A free-piston combustion member comprising air compression and gas expansion chambers is combined with a rotary motor. The rotary motor shaft drives an air compressor, receives power from the gases expanding in an expansion chamber and provides residual torque and power for external use. Two combustion chambers located at each end of the free piston receive compressed air and fuel for combustion outside of the rotary motor assembly. The motion of the free piston between the two combustion chambers is independent of the motor rotary motion. The air admission inside the combustion chambers, the fuel injection and the combustion initiation process are all controlled and timed by the free piston movement back and forth. A heat exchanger is located between the combustion-chamber/free-piston assembly and the rotary motor. It also serves as storage tank for the compressed air before its admission in the combustion chambers in order to smooth out pressure surges in the compressed air entering the combustion chambers.

Abstract: A positive displacement machine, particularly an internal combustion engine, comprises an oscillating piston connected to a piston pump. The cylinder of the pump is connected through valves to a pressure accumulator and to a substantially pressureless tank. The piston of the motor is integral with the piston of a pump. The valves of the pump are positively actuated by a separate motor.

Abstract: A free piston combustion chamber coupled to air compression and gas expansion chambers are combined with a rotary motor. The rotary motor shaft drives the air compressor, receives power from the expanding gases in the expansion chamber and provides residual torque and power for external use. Two combustion chambers located at each end of the free piston receive compressed air and fuel for combustion outside of the rotary motor assembly. The motion of the free piston between the two combustion chambers is independent of the motor rotary motion. The air admission inside the combustion chambers, the fuel injection and the combustion initiation process are all controlled and timed by the free piston movement back and forth. The compressed air exiting from the compression chamber is heated by the gases exiting from the combustion chambers, before they are admitted into the expansion chamber of the rotary motor.

Abstract: A power plant including a vane type engine having fuel compression means and a gas expansion means. Air or an air-fuel mixture compressed by the vanes in the compression means is fed to a free piston combustion member where burning takes place and gases are returned to the gas expansion means of the engine to drive the power shaft.

Abstract: A two-stroke combustion engine is described which has a symmetrical, floating differential piston (14), having at least two main piston portions (16, 18), each movable in a combustion chamber (28, 30) formed with exhaust ports (46), and each connected to a pre-compression chamber (34, 36) by means of a respective channel (38, 40). The combustion chambers (28, 30) are arranged axially inward of the piston portions and between the chambers lies the pre-compression chamber (32) in which a central double-acting piston portion (22) of the differential piston (14) is arranged on a piston rod (20). The central piston portion (22) divides the pre-compression chamber (32) into two separate supercharging chambers (34, 36), from which the channels (38, 40) leading to the combustion chambers (28, 30) terminate at the end walls of the respective combustion chambers.

Abstract: A free piston gasifier is described capable of burning porous solid char fuels alone or with oil fuels. Air is forced into the char pore spaces during the compression process of the cycle in order to achieve the rapid burning needed for reasonable gasifier speeds. Fresh char fuel is periodically furnished into a combustion chamber and ashes are removed therefrom. Gasifier output is controlled by control of intake air density.

Abstract: Reciprocating drive means powered by a fluid such as compressed air comprising an elongate inner member with a plurality of passageways therein, an outer member slidable on the inner member and a shuttle member slidable with respect to the inner member and within the outer member, the passageways in the inner member being variously and intermittently so connected in use to each other by way of ports in the inner member and compartments provided within the outer member and the shuttle that, upon connection of a determined one of said passageways to a fluid pressure source the outer member moves with reciprocating action with respect to the inner member.

Abstract: A free piston gas generator assembly in which the scavenging efficiency of the power cylinder is increased, by interconnecting in series a plurality of three or more identical motor-compressor cylinders, by means of a piping system, into one engine assembly. Said interconnecting piping system constitutes a closed feedback or bounce energy transfer loop, by transferring the feedback or bounce energy of the up-stream motor-compressor cylinder to the down-steam motor-compressor cylinder in a continuous stepwise sequence. Consequently, the simultaneous outward and inward synchronized piston strokes of two motor-compressor cylinders in each working step, causes the pistons of the remaining motor-compressor cylinders in the assembly to be at rest in the outward dead points, where scavenging takes place.

Abstract: A fuel injected free piston-turbine heat engine wherein a piston moves reciprocally within a cylinder to deliver gases to an impulse turbine powering a fan-scavenged two-stroke cycle operation of said piston, there being a low compression storage chamber of substantial volume normally open into the cylinder and closed by upward movement of the piston to withhold gases at combustion supporting temperature, there being a high compression auto ignition chamber of limited volume comprising the upper portion of the cylinder and isolated from said low compression chamber by said piston closure thereof for continued compression of combustion supporting gases by said piston movement to auto ignition temperature, and there being constant volume fuel injection means for injecting fuel at high pressure into the auto ignition chamber and at a progressively diminishing rate as the first mentioned storage chamber is re-opened and as the cylinder pressure decreases during the effective power stroke.

Abstract: A double acting Diesel cycle hot gas engine comprising a plurality of engine cylinders, each having a free piston unit adapted to perform work, providing a continuous flow of compressed air to an energy consumption source and to a storage tank connected therewith. The free piston unit includes an air compression piston and a power piston, spaced apart from each other and adapted to move together within each respective engine cylinder through a connecting rod extended therebetween in response to the movement of a working medium under a substantially constant pressure acting against one side of the power piston and to the pressure and expansive power generated by the burning gases of an air fuel mixture acting on the opposite side of said power piston. Cycle control means are provided to release the potential energy accumulated within the working medium which is initially used to drive the power piston to compress the air fuel mixture and thus, initiating the operative cycle of the engine.

Abstract: An illustrative system is disclosed for use as a rotary-drive engine, utilizing combustible fuel and a hydraulic system of energy conversion. An engine block defines a pair of expansion cylinders (combustion chambers) and an associated concentric pair of hydraulic chambers. The chambers matingly receive unitary piston structures for phase-opposed reciprocal movement.The hydraulic working chambers communicate with each other and can exhaust high pressure fluid through a control valve structure for drive power. Exhausted fluid is replaced in volume by low-pressure spent fluid. The body of the fluid contained in the hydraulic working chambers along with the piston means and springs connected to the engine block define an oscillatory system which is resonant at the operating frequency. That consideration, along with the absence of lateral loads on the pistons, results in relatively high efficiency.