| 摘要 |
An automated powershift multi-speed transmission adapted to transfer power from the engine to the driveline of a motor vehicle. The transmission includes an engine clutch assembly having a primary clutch operable to establish a releasable drive connection between the engine and a first input shaft, and a secondary clutch operable to establish a releasable drive connection between the engine and a second input shaft. The transmission also includes an output shaft adapted to transfer power to the driveline, and a geartrain for selectively establishing a plurality of forward and reverse speed ratio drive connections between the input shafts and the output shaft. In addition, the transmission includes power-operated dog clutches for selectively engaging constant-mesh gearsets associated with the geartrain, and a transmission controller for controlling coordinated actuation of the engine clutch assembly and the power-operated dog clutches to permit non-power interrupted ("powershift") sequential gear changes automatically without input from the vehicle operator. A clutch control system includes a first hydraulic pump driven by the first input shaft, a second hydraulic pump driven by the second input shaft, and flow control valving for controlling fluid flow between the first and second pumps. When shifting under power between gear ratios, one of the clutches associated with the engine clutch assembly is released such that the pump associated with the driven input shaft supplies fluid to the pump associated with released input shaft for causing acceleration/deceleration of the released input shaft into synchronization with the output shaft. Following completion of speed synchronization, the dog clutch for the selected gearset associated with the released input shaft is actuated and thereafter the released clutch is re-engaged and the engaged clutch is released.
|
