| 摘要 |
A multi-speed constant mesh dual clutch gearbox having two clutches 24, 25 two coaxial input shafts 21, 22, one coincident output shaft 23, two or more forward speed ratios and two or more reverse speed ratios. Power or hot shifting between the two or more reverse speed ratios is possible. The speed ratios comprise individually selectable gear wheel trains, e.g. 61, 64, 71, 74, 81, 82, 83 and 84. The gear wheels are selectively connectable to shafts to provide forward and reverse speed ratios. Reverse speed ratio is via a sleeve 85, 86 mounted on a reverse layshaft 35 and rotationally coupled to input shaft 21, 22 via an idler gear wheel 64, 74, 81, 81. The sleeve 85, 86 can also re-circulate torque to a forward layshaft 31 to provide an additional low forward speed ratio. A central web 39 contains centre support bearings (45, 33, 37, fig 1) for the shafts. |
