Patent ID: 7803075

Claim:
A vehicle transmission comprising: a crankshaft box unit including a crankshaft box and a crankshaft journalled within said crankshaft box; a clutch unit disposed in proximity to said crankshaft box unit and including a seal cover cooperating with said crankshaft box to define a clutch chamber therebetween, a wet clutch disposed within said clutch chamber and rotatable with said crankshaft, and a unidirectional clutch for controlling unidirectional rotation of said wet clutch; a transmission box unit disposed in proximity to said clutch unit; and lubricating oil disposed in said clutch unit and said crankshaft box unit; wherein said crankshaft of said crankshaft box unit extends through said seal cover of said clutch unit, and has an insertion end portion extending into said transmission box unit, said crankshaft box unit further including a driven shaft disposed in said transmission box unit and having an oil-storing end portion that is sleeved coaxially on said insertion end portion of said crankshaft and that extends into said seal cover, said oil-storing end portion defining a lubricating space that receives said unidirectional clutch and that is filled with said lubricating oil, said unidirectional clutch being disposed outwardly of said seal cover; wherein said crankshaft box unit further includes: a first bearing disposed between an outer surface of said insertion end portion of said crankshaft and an inner surface of said oil-storing end portion of said driven shaft and outwardly of said crankshaft box; and a second bearing disposed between an inner surface of said seal cover and an outer surface of said oil-storing end portion of said driven shaft, said unidirectional clutch being located between said first and second bearings; and wherein said crankshaft includes: an axial central passage unit having an upstream passage portion permitting flow of said lubricating oil therethrough when said lubricating oil is fed into said crankshaft, and a downstream passage portion spaced apart from and aligned with said upstream passage portion and having a bearing-insertion end portion that forms a portion of said insertion end portion of said crankshaft and that is communicated with said lubricating space in said oil-storing end portion of said driven shaft of said crankshaft box unit; and a hollow conduit member defining an elongated interior chamber that is parallel to said upstream and downstream passage portions of said central passage unit and that is communicated with said upstream and downstream passage portions of said central passage unit so as to allow for flow of said lubricating oil from said upstream passage portion into said downstream passage portion via said interior chamber in said conduit member.