A variable-stroke reciprocating internal combustion engine, the engine having an engine shaft and a piston configured to reciprocate within a cylinder chamber having an axis, each piston having a first piston part operable to move in unison with or separat...

A spring-based crankshaft coupling structure used in an engine and coupled between a piston and a crankshaft to enhance the output torque of the engine is disclosed to include a first coupling member pivoted to the piston, the first coupling member having ...

The present invention relates to an engine in which the stroke of a piston at an expansion stroke is larger than that at a compression stroke. In order to ensure that a top dead center at each of intake and exhaust strokes and a top dead center at the comp...