摘要 |
A plurality of gear trains (1M,2M,3M,4M,5M) mounted on a parallel disposed input shaft (8) and an output shaft (19) in an automatic transmission have different gear reduction ratios. A transmitting torque varying means is also incorporated in the automatic transmission so as to enable gears to be shifted without disengaging a clutch. In consequence, the time required to engage and disengage the clutch can be reduced, occurrence of non-transmission of torque can be eliminated during gear-shifting, and impact caused by engagement of the clutch can be prevented. Therefore, smooth gear-shifting is possible without making a driver feel as if a vehicle is losing power or speed. The parts of a known automatic transmission can be employed except for synchronizing devices which are replaced by transmitting torque varying means. Further, a one-way clutch (F) is incorporated in the automatic transmission so as to reduce the time needed to shift gears between a 1st speed range and a 2nd speed range. Since the output shaft (19) is driven only when an accelerating pedal (11) is depressed and a vehicle becomes in a free running state while the accelerating pedal (11) is not being depressed. Therefore, no jolting occurs which would otherwise occur when the accelerating pedal (11) is depressed or released. |