Linear generators with a piston having a valve are described herein. The linear generator includes a combustion module and at least one linear motor. The linear motor includes at least one piston having: a piston head with an opening therein; a piston skirt opposed to the piston head; a piston side wall extending between the piston head and the piston skirt, the piston side wall having at least one port therein. The piston also includes a valve mechanism movable relative to each of the piston head, the piston seat and the piston side wall. The valve mechanism includes a valve stem extending through the piston skirt and the interior piston volume into a mover shaft of the motor, and a valve head coupled to the valve stem and configured to cover the opening of the piston head.

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.

Linear generators with a piston having a valve are described herein. The linear generator includes a combustion module and at least one linear motor. The linear motor includes at least one piston having: a piston head with an opening therein; a piston skirt opposed to the piston head; a piston side wall extending between the piston head and the piston skirt, the piston side wall having at least one port therein. The piston also includes a valve mechanism movable relative to each of the piston head, the piston seat and the piston side wall. The valve mechanism includes a valve stem extending through the piston skirt and the interior piston volume into a mover shaft of the motor, and a valve head coupled to the valve stem and configured to cover the opening of the piston head.

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.

An opposed, free-piston engine includes a pair of adjacent cylinders, each extending from a first cylinder end to a second cylinder end along an elongate axis and having a first cylinder housing a first pair of opposed, free pistons including a first piston housed towards the first cylinder end and a second piston housed towards the second cylinder end; a second cylinder housing a second pair of opposed, free pistons having a third piston and a fourth piston; and a pair of link rods including a first link rod and a second link rod. The first link rod has a first link rod end and a second link rod end, the second link rod having a third link rod end and a fourth link rod end.

The present converter for converting reciprocating motion into rotary motion comprises a pair of rotors counter-rotating in axial alignment, said rotors having rotor magnets and auxiliary rotor magnets fastened thereon, and a pair of rods moving reciprocally in opposite directions relative to one another along the axis of rotation of the rotors, said rods having rod magnets and auxiliary rod magnets fastened thereon, wherein at least some of the rotor magnets and/or the rod magnets are arranged such that their poles are disposed on several concentric cylindrical working surfaces simultaneously.

An internal combustion 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 therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

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.

According to an exemplary embodiment of the present invention, since the pressure space of the cylinder is bisected into a vacuum state and a pneumatic state to alternately form a pressure difference, it is possible to generate the kinetic energy of the piston and convert the kinetic energy into other necessary energy. To this end, an exemplary embodiment of the present invention provides an energy conversion apparatus including an energy conversion module including a piston, a piston rod provided on one side of the center of the piston, a cylinder divided into a first pressure space and a second pressure space to be relatively varied with the piston interposed therebetween, and an external air opening/closing part selectively opening and closing the external air to the first pressure space and the second pressure space, respectively; a first bellows containing a fluid therein and provided in the first pressure space to be compressed and expanded; a second bellows containing a fluid therein and provided in the second pressure space to be compressed and expanded; a fluid movement pipe which is positioned outside the cylinder and connects the first bellows and the second bellows to each other to form a closed space, and through which the fluid accommodated therein moves by pressure; a first bellows pressing part for pressing one side of the first bellows; second bellows pressing part for pressing one side of the second bellows; a first motor transmitting a driving force to the first bellows pressing part; and a second motor transmitting a driving force to the second bellows pressing part.

Boosting systems for converting heat into useable work. The systems can be modular with the ability to add boost chambers as modules to a base design. The systems can have driving chambers with volumes that are mechanically adjustable.