Split-cycle air hybrid engine

A split-cycle air hybrid engine comprising:

• a crankshaft rotatable about a crankshaft axis;
• a power piston slidably received within a power cylinder and 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 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 during a single rotation of the crankshaft;
• a gas passage interconnecting the compression and power cylinders, the gas passage including an inlet valve and an outlet valve defining a pressure chamber therebetween;
• and
• an air reservoir connected by a first reservoir passage directly to the power cylinder and a second reservoir passage directly to the compression cylinder, the air reservoir separated from direct connection with the crossover passage and connected in parallel therewith, the air reservoir 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.

A split-cycle air hybrid engine comprising:

• a power piston slidably 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 rotation of the crankshaft;
• a compression piston 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 during a single rotation of the crankshaft;
• an air reservoir operatively connected between the compression cylinder and the power cylinder and 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;
• and
• valves to control gas flow into and out of the compression and power cylinders and the air reservoir, wherein:
• the power cylinder is selectively operable to place the power piston in the following modes:
• a power mode, wherein compressed air from the air reservoir or the compression cylinder is delivered, with or without fuel, to the power cylinder;
• and
• an idle mode, wherein compressed air from the air reservoir or the compression cylinder is not delivered to the power cylinder.