| 摘要 |
<p>The transmission comprises gear trains each being one of a set providing a series of increasing speed ratios and two clutches (12, 13) independently operable and providing alternative drive paths through the gear trains between a common input shaft (11) and a common output shaft (14). The gear trains of alternate ratios in the set are driven respectively through one and the other clutch. One clutch (13) is arranged to drive the output shaft (14) through a first four wheel gear train or through a second four wheel gear train, the gear trains having common first and second gear wheels (21, 22 and 23, 24 or 21, 22 and 23, 30). The other clutch (12) is arranged to drive the output shaft (14) either directly or through a third four wheel gear train which includes gear wheels which are members of at least one of the first and second mentioned four wheel gear trains. The second and third gear wheels of each respective four wheel train are coaxial about a layshaft (15) and one of the gear wheels (24; 30) on the layshaft (15) is journalled for rotation thereon and is selectively drivably connectable to the layshaft.</p> |
