摘要 |
An automatic transmission for a vehicle includes a first planetary gear set (1) including a first element (11), a second element (14), and a third element (12) which correspond to a teeth number ratio on a common velocity diagram; and a Ravigneaux type second planetary gear set (2). An input shaft (1) is constantly connected to the second element (14), and arranged to be connected to a second sun gear (21) by an engagement of a first clutch (4), and arranged to be connected to a third sun gear (26) by an engagement of a second clutch (6). An output member is constantly connected to a second ring gear (22). The first element is arranged to be fixed to a stationary portion (8) by an engagement of a first brake (3). The third element (12) is constantly connected to a second pinon carrier (25), and arranged to be fixed to the stationary portion (8) by an engagement of a second brake (6). The third sun gear (26) is arranged to be fixed to the stationary portion (8) by an engagement of a third brake (7). |