Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

A linear reciprocating engine may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The engine may further include a first piston rod portion extending from a first face of the double-faced piston through the first combustion chamber, and a second piston rod portion extending from a second face of the piston through the second combustion chamber. Passageways in the piston rod portions may be configured to communicate gases between the combustion chamber and a location outside the cylinder and configured to prevent gases from being exchanged between the cylinder and a location outside the cylinder via a path that crosses both face of the piston.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

The present invention concerns an air motor comprising a piston and a housing, the piston being received in the housing and dividing the housing into two primary chambers of variable volume. Said motor comprises a first direct supply valve for supplying a first primary chamber of the two primary chambers and a second direct supply valve for supplying the other primary chamber, said two valves each being movable relative to at least one respective seat. The first valve and the second valve are mounted on a same stem movable relative to the housing in a direction parallel to the direction of movement of the piston, and the stem is configured to be moved between a first position and a second position by moving means activated by the piston.

A vapor powered electro-mechanical generator comprises a cylinder, which is sealed at both ends in which two pistons slidingly move in opposite directions simultaneously. A tube on which the pistons also slide lies at the center of the longitudinal axis of the cylinder. The tube transfers vapor from the inlet to the pressurized side of the pistons to actuate pistons, while one or more exhaust valves are simultaneously opened on the opposite end of the piston stroke allowing the expanded vapor to flow to a condensing system. The pistons consist of magnets at their peripheral circumference. As the vapor expands, the pistons magnets move through coils of conductive wire producing electric current. Further, repulsion magnets repel corresponding piston magnets to provide a cushioned rebound effect while conserving momentum of the generator.

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.

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.