| 摘要 |
<p>The invention relates to a multi-speed automatic transmission for private cars or commercial vehicles. The inventive transmission comprises an input shaft (E), an output shaft (S), two power paths (P1 and P2), a double planetary gear train (50), a first brake (B1) and a second brake (B2). According to the invention, the first power path (P1) has a first speed ratio (G1) and comprises a first clutch (C1) and a second clutch (C2). The second power path (P2) has a second speed ratio (G2), which is greater than the first speed ratio (G1) and in the same direction, and comprises a third clutch (C3) and a fourth clutch (C4). The transmission has eight forward speeds and two reverse speeds and is highly flexible. In one embodiment of the invention, the transmission is reduced to six forward speeds and one reverse speed with the removal of the second clutch (C2). In the first embodiment of the invention, the input shaft (E) and the output shaft (S) are aligned and the ratios (G1 and G2) are supplied respectively by a planetary gear train (10) and a direct drive. In a second embodiment of the invention, the input shaft (E) and the output shaft (S) are parallel and the ratios (G1 and G2) are supplied respectively by two parallel gear trains (1 and 2) comprising constant mesh gears.</p> |
