Patent ID: 7621195
Filing Date: 2009-11-24
Classification: F16H,Y10T

Abstract:
1. A vehicle transmission comprising: a first input shaft having a plurality of first input gears; a second input shaft coaxially arranged with respect to the first input shaft and having a plurality of second input gears; a first clutch arranged to operatively transmit a driving torque of a power source to the first input shaft; a second clutch arranged to operatively transmit the driving torque of the power source to the second input shaft; a first output shaft having a plurality of first output gears engaged with selected ones of the first and second input gears to define a plurality of gear pairs that each selectively receives the driving torque from one of the first and second input shafts; a second output shaft having a plurality of second output gears engaged with selected ones of the first and second input gears to define a plurality of gear pairs that each selectively receives the driving torque from one of the first and second input shafts; a countershaft having a plurality of third output gears with the countershaft being disposed in parallel with the first and second output shafts such that the third output gears are engaged with selected ones of the first and second input gears to define a plurality of gear pairs that each selectively receives the driving torque from one of the first and second input shafts; and a plurality of gear selectors operatively disposed to selectively connect and disconnect the first output shaft to selected ones of the first output gears, the second output shaft to selected ones of the second output gears, and the countershaft to selected ones of the third output gears in order to selectively establish a plurality of forward driving speed ratios and at least one reverse driving speed ratio by selectively controlling the gear selectors and the first and second clutches, the first input gears, the second input gears, the first output gears, the second output gears and the third output gears being selectively connected such that no more than two sets of the gear pairs are used in establishing a torque transmitting path from one of the first and second input shafts to a final reduction gear output shaft when a forward gear is selected among the forward driving speed ratios other than a first forward gear.