Power transmission unit for a motorcycle

摘要

A power transmission unit for a motorcycle is disclosed which includes a power unit case consisting of a crankcase and a transmission case both of which are integrally formed with one another. A bevel gear case incorporating therein a bevel gear assembly is detachably secured to the power unit case at a recessed section of the latter. The recessed section is located rearwardly of a generator which is disposed at the outermost part of the power unit case. The bevel gear assembly comprises a driving bevel gear connected with a countershaft in the power unit case, and a driven bevel gear connected with a final shaft which is in turn connected to a rear wheel. Both the driving and driven bevel gears are rotatably supported in the bevel gear case by means of bearings received in bearing holders which are detachably secured to the bevel gear case by means of tightening bolts, whereby the bevel gear case is mounted on or dismounted from the power unit case with the driving and driven gears incorporated in the bevel gear case.