Abstract: An engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston is operable to reciprocate through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion (power) piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston is operable to reciprocate through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. At least two crossover passages interconnect the compression and expansion cylinders. Each of the at least two crossover passages includes a crossover compression (XovrC) valve and a crossover expansion (XovrE) valve operable to define a pressure chamber therebetween. The engine controls and maximizes engine efficiency at part-load by utilizing only selected crossover passages.

Abstract: An engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston is operable to reciprocate through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion (power) piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston is operable to reciprocate through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A variable volume crossover passage interconnects the compression and expansion cylinders, and includes a variable volume housing to controllably regulate the air flow from the compression cylinder to the expansion cylinder.

Abstract: A split-cycle engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through intake and compression strokes during a single rotation of the crankshaft. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through expansion and exhaust strokes during a single rotation of the crankshaft. A crossover passage interconnects the expansion and compression cylinders. The crossover passage includes crossover compression (XovrC) and crossover expansion (XovrE) valves defining a pressure chamber therebetween. At least one of the XovrC and XovrE valves is a balanced valve.

Abstract: An engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston is operable to reciprocate through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion (power) piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston is operable to reciprocate through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A variable volume crossover passage interconnects the compression and expansion cylinders, and includes a variable volume housing to controllably regulate the air flow from the compression cylinder to the expansion cylinder.

Abstract: An engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston is operable to reciprocate through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion (power) piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston is operable to reciprocate through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. At least two crossover passages interconnect the compression and expansion cylinders. Each of the at least two crossover passages includes a crossover compression (XovrC) valve and a crossover expansion (XovrE) valve operable to define a pressure chamber therebetween. The engine controls and maximizes engine efficiency at part-load by utilizing only selected crossover passages.

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 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.