摘要 |
A camshaft drive system is described for a selectable two-stroke/four-stroke internal combustion engine with exhaust and intake poppet valves opened and closed by at least one camshaft. In the system, the camshaft is connected permanently to a planetary gear set (10, 12, 14, 15, 16) which is driven continuously by the engine crankshaft (20), and means are provided for setting the planetary gear set in one of two selectable stable modes to function either as a gearbox or as a rigid coupling. |