Dual-cylinder expander engine and combustion method with two expansion strokes per cycle

摘要

An internal combustion engine is provided with an expansion cylinder and at least one combustion cylinder, preferably two or four combustion cylinders per expansion cylinder. An air-fuel mixture is ignited within the combustion cylinders to drive a combustion piston which, in turn, drives an engine crankshaft. The gaseous products of combustion are exhausted at a pressure substantially above atmospheric to an expansion cylinder wherein they are allowed to further expand against an expander piston to drive an expander crankshaft. Torque produced at the engine crankshaft and torque produced at the expander crankshaft are combined to drive vehicle wheels.