| 摘要 |
A power transmission for a four-wheel drive vehicle includes a change-speed gearing (20) mounted within a transmission casing (11), and an intermediate differential unit (30a) assembled within the transmission casing and drivingly connected to an output shaft (20) of the change-speed gearing to be applied with a driving torque through the change-speed gearing for transmitting the driving torque to a first drive shaft (15) for front-wheel drive and to a second drive shaft (17) for rear-wheel drive. The differential unit comprises a differential casing (31) rotatably mounted within the transmission casing and drivingly connected to the output shaft of the change-speed gearing, a pair of pinion gears (32) rotatably mounted within the differential casing, a plurality of first side gears (33a-33c) concentrically mounted within the differential casing for relative rotation and being meshed with the pinion gears, the first side gears being formed in different diameter and arranged to be drivingly connected to one of the drive shafts, a second side gear (34) rotatably mounted within the differential casing, the second side gear being meshed with the pinion gears and drivingly connected to the other drive shaft, and a shift mechanism (30b) for selectively connecting the first side gears to the one of the drive shafts. |
