| 摘要 |
The invention provides an automatic powershifting vehicle transfer case comprising a housing supporting a rotatably driven input shaft, a first output shaft rotatably coupled to one of the front or rear axles of a vehicle, and a second output shaft rotatably coupled to the other of the front or rear axles. A first planetary gear set has a first high speed range operating position, where torque from the input shaft is transferred to one or both of the front or rear axles of the vehicle with no speed reduction from planetary operation. The first planetary gear set includes a sun gear connected to rotate with the input shaft, a ring gear, and pinion gears supported in a carrier, with the planetary gear set being drivingly coupled to at least one of the output shafts. A first clutch associated with the first planetary gear set provides a predetermined output drive ratio to one or both of the output shafts. A second planetary differential gear set is associated with the first output shaft and has second clutch associated therewith to control torque transfer to the second output shaft in four-wheel drive modes of operation. The rotational speed of the first and second output shafts can be monitored, and the second clutch can be actuated to selectively lock the second planetary differential if there is a predetermined difference in rotational speeds between the first and second output shafts. Operation of the clutch is automatically effected such that torque received at the input shaft is selectively transferred to drive the first and second output shafts in a predetermined manner. Four-wheel drive modes are provided by a front output clutch assembly which selectively transfer torque to the front output shaft.
|
