| 摘要 |
An automotive transmission comprises a plurality of cascaded planetary-gear stages consisting each of a sun gear, a planet carrier and a ring gear. The stages, or some of them, constitute modular units which may be added or eliminated to vary the number of available speed ratios. With four stages and eight selectively operable coupling elements, i.e., four clutches and four brakes, eight forward speeds and six reverse speeds may be realized. The sun gears of three stages are fixed to a common intermediary shaft, connectable to an input shaft by one of the clutches, while the corresponding ring gears are individually immobilizable by respective brakes. Two of the three components of the fourth stage, namely the carrier and the ring gear, are cross-connected with the ring gear and the carrier of the third stage and, like the sun gear of this fourth stage, may be individually linked with the input shaft via other intermediate shafts and associated clutches. The planet carrier of the first stage is fixed to an output shaft while the carrier of the third stage is rigid with the ring gear of the second stage; the carrier of the second stage is fixedly connected with either the ring gear or the carrier of the first stage. |
