| 摘要 |
<p>The present invention provides a power train for an automatic transmission of a vehicle, including: an input axle for delivering power from an engine; a main-transmission mechanism (6) having a compound planetary gear unit (4) for outputting the power as four speed ratios; a sub-transmission mechanism (10) having a simple planetary gear unit (8) for increasing a speed ratio which is output from the main-transmission mechanism (6) as the largest speed ratio of the four speed ratios; the main-transmission mechanism (6) including a first friction element (C1) for selectively transmitting the power from the input axle (21) to a first sun gear (12) of the compound planetary gear unit (4), a second friction element (B1) for making a second sun gear (14) of the compound planetary gear unit (4) as an idling element, a third friction element (C2) for selectively transmitting the power from the input axle (21) to a planet carrier (16) of the compound planetary gear unit (4), and a fourth friction element (B2) for operating the sun gear (14) as a reacting force element; and the sub-transmission mechanism (10) including a fifth friction element (B3) for operating a third sun gear (40) of the simple planetary gear unit (8) as the reacting force element.</p> |
