摘要 |
An automatic transmission includes a first planetary gear set; a second planetary gear set; a third planetary gear set; an input shaft; an output shaft; and five friction elements. A first ring gear is constantly locked. A third carrier is connected with a second ring gear to define a rotating member. The input shaft is constantly connected with a second carrier, and the output shaft is constantly connected with the rotating member. The five friction elements include a first friction element adapted to selectively connect a first carrier with a third ring gear; a second friction element adapted to selectively connect a first sun gear with the second carrier; a third friction element adapted to selectively connect the first sun gear with a second sun gear; a fourth friction element adapted to selectively connect the first carrier with the second carrier; and a fifth friction element adapted to selectively connect the first carrier with the second sun gear. Each of at least seven forward speed-ratios and one reverse speed-ratio is achieved by an engaged state of two friction elements selected from the five friction elements. |