| 摘要 |
A drive unit, such as a transfer case, is located in a power path between a transmission output 40 and driven wheels (10, 12, fig 1) of a hybrid vehicle. The unit has a reverse power path which comprises a reverse pinion 58 secured to a layshaft 56, a reverse idler 60 meshing with pinion 58 and reverse gear 64 journalled on an intermediate shaft 66. When a selector sleeve 67 of coupler 46 is engaged with the reverse pinion 58 a power path which includes pinion 52, gear 54, layshaft 56, reverse pinion 58, idler 60 and reverse gear 64 is formed and in this way the intermediate shaft 66 is underdriven in a reverse direction relative to a direction of an input shaft 44. Input shaft 44 is connected to an output of a transmission 42 which may be transversely arranged (fig 4). The unit also includes low-range and high-range power path and a 4x4 coupler 50 which engages/disengages a second output shaft 78 coupled to a rear drive shaft 18 in order to provide four wheel drive. Planetary gearsets (fig 3) may be used to split torque between front and rear drive shafts 18, 20. In another embodiment the reverse gears/pinions may be planetary gears (fig 5). |
