| 摘要 |
To allow a center distance between a crankshaft (5) and a gearshift shaft disposed in parallel with each other to be kept small and a power unit to be built compactly in a direction of arrangement of the crankshaft (5) and the gearshift shaft, and to support reliably the gearshift shaft on which heavy, first and second gearshift clutches are supported. A transmission (M) of a power unit (P) includes a main shaft (30), which is disposed in parallel with a crankshaft (5) and rotatably supported in a crankcase (2), and first and second gearshift clutches (41, 42). The first and second gearshift clutches (41, 42) change a gearshift position in a first gearshift portion and a gearshift position in a second gearshift portion, respectively. The main shaft (30) includes an outer shaft portion (31b) that extends from the crankcase (2) and supports the first and second gearshift clutches (41, 42). Further, the outer shaft portion (31b) is supported by a bearing portion (150) disposed in a front cover (10) on a side opposite to the crankcase (2) across the first and second gearshift clutches (41, 42). |
