| 摘要 |
PROBLEM TO BE SOLVED: To reduce the size of an outside dimension and weight while increasing the number of shift stages in a stepped automatic transmission having a planetary gear mechanism and a frictional engagement element.SOLUTION: An automatic transmission includes an input shaft (S1) into which a drive force from a drive source is inputted, an output shaft (L2) connected to a member at a predetermined destination of an output, a first planetary gear mechanism (PG1) and a second planetary gear mechanism (PG2) which are installed between the input shaft (S1) and the output shaft (L2), and a plurality of clutches (C1-C5) and brakes (B1, B2) which are coupled to each rotating element of the first and second planetary gear mechanisms (PG1, PG2). A plurality of shift stages are established by changing over the engagement and locking of the clutches (C1-C5) or the brakes (B1, B2). The second planetary gear mechanism (PG2) is constituted of a Ravigneaux type planetary gear mechanism having a stepped long pinion gear (LP). |
