Abstract: A split-cycle aircraft engine includes a crankshaft rotatable about a crankshaft axis. A power piston is slidably received within a power cylinder and is operatively connected to the crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A compression piston is slidably received within a compression cylinder and is operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke during a single rotation of the crankshaft. A gas crossover passage operatively interconnects the compression cylinder and the power cylinder. An air reservoir is operatively connected to the gas crossover passage by a reservoir passage. The air reservoir is selectively operable to receive and deliver compressed air. The engine is mounted to an aircraft and the air reservoir is disposed within the aircraft.

Abstract: An engine has a crankshaft, rotating about a crankshaft axis of the engine. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through an expansion stroke and an exhaust stroke of a four stroke cycle during a single rotation of the crankshaft. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke of the same four stroke cycle during the same rotation of the crankshaft. A ratio of cylinder volumes from BDC to TDC for either one of the expansion cylinder and compression cylinder is fixed at substantially 26 to 1 or greater.

Abstract: An engine has a crankshaft, rotating about a crankshaft axis of the engine. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through an expansion stroke and an exhaust stroke of a four stroke cycle during a single rotation of the crankshaft. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke of the same four stroke cycle during the same rotation of the crankshaft. A ratio of cylinder volumes from BDC to TDC for either one of the expansion cylinder and compression cylinder is fixed at substantially 26 to 1 or greater.

Abstract: An engine has a crankshaft, rotating about a crankshaft axis of the engine. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through an expansion stroke and an exhaust stroke of a four stroke cycle during a single rotation of the crankshaft. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke of the same four stroke cycle during the same rotation of the crankshaft. A ratio of cylinder volumes from BDC to TDC for either one of the expansion cylinder and compression cylinder is fixed at substantially 26 to 1 or greater.

Abstract: A waste heat recovery system for a split-cycle engine includes a heat exchange unit. An air compressor device is in communication with the heat exchange unit. A waste heat input receives waste heat from the engine and is in fluid communication with the heat exchange unit. An ambient air intake connected to the air compressor device draws air into the air compressor device. A compressed air outlet member on the air compressor device in fluid communication with a compression cylinder of the split-cycle engine delivers compressed air from the air compressor device to the engine. Engine waste heat is communicated to the heat exchange unit and energy from the waste heat is used to drive the air compressor device, causing the air compressor device to draw in ambient air through the ambient air intake, compress the ambient air, and deliver compressed air to the engine through the compressed air outlet.

Abstract: A split-cycle aircraft engine includes a crankshaft rotatable about a crankshaft axis. A power piston is slidably received within a power cylinder and is operatively connected to the crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A compression piston is slidably received within a compression cylinder and is operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke during a single rotation of the crankshaft. A gas crossover passage operatively interconnects the compression cylinder and the power cylinder. An air reservoir is operatively connected to the gas crossover passage by a reservoir passage. The air reservoir is selectively operable to receive and deliver compressed air. The engine is mounted to an aircraft and the air reservoir is disposed within the aircraft.

Abstract: A split-cycle aircraft engine includes a crankshaft rotatable about a crankshaft axis. A power piston is slidably received within a power cylinder and is operatively connected to the crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A compression piston is slidably received within a compression cylinder and is operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke during a single rotation of the crankshaft. A gas crossover passage operatively interconnects the compression cylinder and the power cylinder. An air reservoir is operatively connected to the gas crossover passage by a reservoir passage. The air reservoir is selectively operable to receive and deliver compressed air. The engine is mounted to an aircraft and the air reservoir is disposed within the aircraft.

Abstract: A split-cycle engine with disc valve includes a crankshaft, a power cylinder and a compression cylinder. A gas crossover passage interconnects the compression cylinder and the power cylinder. An air intake port circumscribes a periphery of the compression cylinder and defines an outer valve seat. An annular ring having a generally central opening is disposed between the compression cylinder and the air intake port and forms a washer valve for opening and closing the air intake port. A disc valve member is concentrically mounted over the central opening of the annular ring. The disc valve member includes a piston portion having a sidewall biased into engagement with the outer valve seat for controlling flow between the compression cylinder and the gas crossover passage.

Abstract: A split-cycle air hybrid engine operatively connects an air reservoir to a split cycle engine. A power piston is received within a power cylinder and operatively connected to a crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single revolution of the crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke in a single rotation of the crankshaft. The compression cylinder is selectively controllable to place the compression piston in a compression mode or an idle mode. An air reservoir is operatively connected between the compression cylinder and the power cylinder and selectively operable to receive compressed air from the compression cylinder and to deliver compressed air to the power cylinder for use in transmitting power to the crankshaft during engine operation.

Abstract: A four stroke cycle internal combustion engine including a crankshaft, rotating about a crankshaft axis of the engine. A power piston is slidably received within a first cylinder and operatively connected to the crankshaft such that the power piston reciprocates through a power stroke and an exhaust stroke of a four stroke cycle during a single rotation of the crankshaft. A compression piston is slidably received within a second cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke of the same four stroke cycle during the same rotation of the crankshaft. The power piston reciprocates along a first piston-cylinder axis which is offset from the crankshaft axis. The offset substantially aligns a point of maximum combustion pressure applied to the power piston with a point of maximum torque applied to the crankshaft during the power stroke.

Abstract: A four stroke engine including a crankshaft. A power piston within a first cylinder connected to the crankshaft such that the power piston reciprocates through a power stroke and an exhaust stroke. A compression piston within a second cylinder is connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke. A gas passage interconnects the first and second cylinders and includes an inlet valve and an outlet valve defining a pressure chamber therebetween. An inlet manifold is in fluid communication with an inlet valve of the second cylinder. A bypass valve is in fluid communication with the second cylinder and the inlet manifold, wherein during a compression stroke the bypass valve allows a portion of the air to bypass the inlet valve and exhaust into the inlet manifold to provide a variable compression ratio.

Abstract: A four stroke cycle internal combustion engine including a crankshaft, rotating about a crankshaft axis of the engine. A power piston is slidably received within a first cylinder and operatively connected to the crankshaft such that the power piston reciprocates through a power stroke and an exhaust stroke of a four stroke cycle during a single rotation of the crankshaft. A compression piston is slidably received within a second cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke of the same four stroke cycle during the same rotation of the crankshaft. A gas passage interconnects the first and second cylinders. The gas passage includes an inlet valve and an outlet valve defining a pressure chamber therebetween.