Patent ID: 9133758
Filing Date: 2015-09-15
Classification: F02B

Abstract:
1. A split-cycle air-hybrid engine comprising: a crankshaft rotatable about a crankshaft axis; 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 expansion piston 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 during a single rotation of the crankshaft; a cylinder head disposed over an open end of the expansion cylinder to cover and seal the expansion cylinder; a crossover passage interconnecting the compression and expansion cylinders, the crossover passage including a crossover compression (XovrC) valve and a crossover expansion (XovrE) valve defining a pressure chamber therebetween; a crossover expansion (XovrE) valve disposed in the cylinder head and operable to control flow into the expansion cylinder; an air reservoir operatively connected to the XovrE valve through an air reservoir port, the air reservoir selectively operable to store compressed air from a source of high-pressure gas and to deliver compressed air to the expansion cylinder; and the engine being operable in an Air Expander and Firing (AEF) mode, wherein, in the AEF mode, the engine has a residual expansion ratio at XovrE valve closing of 15.7 to 1 or greater.