Two stroke engine with rotatably modulated gas passage

摘要

A two stroke internal combustion engine includes at least one gaseous communication passage between a crankcase chamber and a combustion chamber of the engine. A first rotary shut-off valve on a periphery of a rotatable circular disk is operatively disposed between the passage and the crankcase chamber and rotatably connected to a crankshaft of the engine. The valve includes at least one circumferentially extending pathway extending axially at least partially through the disk and is rotatably alignable with a crankcase port of the passage though the crankcase chamber. The circumferentially extending pathway extends circumferentially less than 180 degrees. Two particular embodiments of the pathways include rectangular cross-sectional slots and annular L-shaped pathways. The gaseous communication passage may be a transfer passage or a charge injection passage or both which are controlled two or more axially adjacent rotary shut-off valves on the periphery of the disk.