Stratified scavenged two-stroke engine

摘要

A two-stroke internal combustion engine includes dual transfer passages in gaseous communication between a crankcase chamber and a combustion chamber of the engine, an air passage through the crankcase to the crankcase chamber and in gaseous communication with a carburetor of the engine. A rotatable circular disk or crank-web is rotatably connected to a crankshaft. A piston may be used to open and close a top end of the passages. An air inlet port to the transfer passage for stratified scavenging is opened and closed by the crank-web that has passages and cutouts. The rotary valve replaces the one-way reed valve used in stratified scavenged and charged two-stroke engines. The air passes from lower ends of the transfer passages to top ends and into the crankcase through a piston passage, through the adjacent transfer passages directly, or through a passage in the piston into the crankcase.