POWER UNITS FOR THE SINGLE CYLINDER ENGINE OR DOUBLE CYLINDER ENGINE

摘要

Family of power units in which a single-cylinder engine (100) or a two-cylinder engine (200) in a V-arrangement, of the type having a head (130) with two shafts of the cams (133, 137) and of an unitary piston-displacement volume not exceeding approx. 250 cu.cm, is in conjunction with a continuously-variable transmission (300) enclosed in a casing (301) and comprising a driving pulley (304) having an axis (P0) which is parallel to or even coincident with the axis of rotation (Z) of the crankshaft (116), a driven pulley (310) and a belt (308) between said pulleys (304, 310), the plane formed by said axis (P0) of the driving pulley (304) and the axis (P.,) of the driven pulley (310) forming an angle comprised between 10° and 20° with the axis (X) of the engine (100), wherein the shaft (316) of the driven pulley (310) is provided with a third support element (318) at the end portion thereof, the said third support element (318) lying on the opposite side with respect to the gearbox (320) that is associated to the said shaft (316).