Abstract: A split-cycle engine includes: a compression chamber, housing a first piston, that induces and compresses working fluid; an expansion chamber, housing a second piston, that expands and exhausts the working fluid; and a transfer chamber, housing a third piston and a fourth piston, wherein the third piston and the fourth piston move relatively to vary a volume within the transfer chamber and to selectively fluidly couple the volume within the transfer chamber to the compression chamber and the expansion chamber. A method of operating an engine includes: inducing working fluid in a first chamber; compressing the working fluid in the first chamber; moving a first moveable boundary of a second chamber; moving a second moveable boundary of the second chamber; expanding the working fluid in the third chamber; and exhausting the working fluid from the third chamber.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: A split-cycle engine includes: a compression chamber, housing a first piston, that induces and compresses working fluid; an expansion chamber, housing a second piston, that expands and exhausts the working fluid; and a transfer chamber, housing a third piston and a fourth piston, wherein the third piston and the fourth piston move relatively to vary a volume within the transfer chamber and to selectively fluidly couple the volume within the transfer chamber to the compression chamber and the expansion chamber. A method of operating an engine includes: inducing working fluid in a first chamber; compressing the working fluid in the first chamber; moving a first moveable boundary of a second chamber; moving a second moveable boundary of the second chamber; expanding the working fluid in the third chamber; and exhausting the working fluid from the third chamber.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: A split-cycle internal combustion engine (ICE) is provided, comprising a compression cylinder, an expansion cylinder and a crossover valve having a valve cylinder housing inside a shuttle and a combustion chamber structure defining a combustion chamber. The shuttle is configured to perform reciprocating motion inside the valve cylinder synchronously with a compression piston and an expansion piston, thereby alternatingly fluidly coupling and decoupling the combustion chamber with the compression cylinder and with the expansion cylinder, selectively. Sealing rings positioned between the valve cylinder and the shuttle prevent gas leaks between them during the reciprocating motion. In some embodiments, a phase shift between the pistons may be set or varied by a piston phase transmission gear. A bi-directional fluid flow split-cycle internal combustion engine (ICE) is also provided having a first cylinder, a second cylinder, a combustion chamber and a single crossover valve fluidly communicating them.

Abstract: An engine includes a compression chamber that intakes and compresses working fluid; an expansion chamber that expands and exhausts working fluid; and a transfer chamber that receives working fluid from the compression chamber and transfers working fluid to the expansion chamber, wherein an internal volume of the transfer chamber decreases during the transfer of working fluid.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: A split-cycle internal combustion engine (ICE) is provided, comprising a compression cylinder, an expansion cylinder and a crossover valve having a valve cylinder housing inside a shuttle and a combustion chamber structure defining a combustion chamber. The shuttle is configured to perform reciprocating motion inside the valve cylinder synchronously with a compression piston and an expansion piston, thereby alternatingly fluidly coupling and decoupling the combustion chamber with the compression cylinder and with the expansion cylinder, selectively. Sealing rings positioned between the valve cylinder and the shuttle prevent gas leaks between them during the reciprocating motion. In some embodiments, a phase shift between the pistons may be set or varied by a piston phase transmission gear. A bi-directional fluid flow split-cycle internal combustion engine (ICE) is also provided having a first cylinder, a second cylinder, a combustion chamber and a single crossover valve fluidly communicating them.

Abstract: An internal combustion engine, including a combustion chamber with a first aperture; a compression chamber with a second aperture; and a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein the first aperture allows fluid communication between the combustion chamber and the internal chamber, the second aperture allows fluid communication between the compression chamber and the internal chamber, the first valve face couples to the first valve seat to occlude the first aperture, and the second valve face couples to the second valve seat to occlude the second aperture.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: An engine includes a compression chamber that intakes and compresses working fluid; an expansion chamber that expands and exhausts working fluid; and a transfer chamber that receives working fluid from the compression chamber and transfers working fluid to the expansion chamber, wherein an internal volume of the transfer chamber decreases during the transfer of working fluid.

Abstract: An internal combustion engine, including a combustion chamber with a first aperture; a compression chamber with a second aperture; and a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein the first aperture allows fluid communication between the combustion chamber and the internal chamber, the second aperture allows fluid communication between the compression chamber and the internal chamber, the first valve face couples to the first valve seat to occlude the first aperture, and the second valve face couples to the second valve seat to occlude the second aperture.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

Abstract: An internal combustion engine, including a combustion chamber with a first aperture; a compression chamber with a second aperture; and a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein the first aperture allows fluid communication between the combustion chamber and the internal chamber, the second aperture allows fluid communication between the compression chamber and the internal chamber, the first valve face couples to the first valve seat to occlude the first aperture, and the second valve face couples to the second valve seat to occlude the second aperture.

Abstract: An internal combustion engine, including a combustion chamber with a first aperture; a compression chamber with a second aperture; and a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein the first aperture allows fluid communication between the combustion chamber and the internal chamber, the second aperture allows fluid communication between the compression chamber and the internal chamber, the first valve face couples to the first valve seat to occlude the first aperture, and the second valve face couples to the second valve seat to occlude the second aperture.

Abstract: An interstage valve for fluidly coupling two chambers of a double-piston engine is disclosed. The interstage valve may include a main valve body, a seal, and an electric coil. When closed, the seal is coupled to the main valve body as a result of electromagnetic forces generated by the electrical coil. The interstage valve is opened when the pressure differential between the engine chambers exceeds the electromagnetic forces. As the interstage valve opens, the electromagnetic forces diminish. The electromagnetic valve moves from the open state to the closed state when the pressure differential reverses. As the seal moves toward the main valve body, the electromagnetic forces increase, coupling the seal to the main valve body.

Abstract: A Dual Piston Cycle Engine utilizes a unique dual piston apparatus that includes: a first cylinder housing a first piston therein; a second cylinder thermally isolated from the first cylinder and housing a second piston therein; an intake valve coupled to the first cylinder for allowing a fuel mixture to enter into the first cylinder; an exhaust valve coupled to the second cylinder for allowing an exhaust gas to exit the second cylinder; and an interstage valve that couples an internal chamber of the first cylinder to an internal chamber of the second cylinder and configured to minimize dead space between the first and second cylinders, wherein the first piston performs only intake and compression strokes and the second piston performs only combustion and exhaust strokes and the first and second cylinders are thermally isolated from one another.