| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic transmission which includes four planetary gear sets and five friction fastening elements and whose increase in size can be suppressed.SOLUTION: The automatic transmission is provided in which: a first carrier C1 and a second ring gear R2 are normally connected to an input shaft 3; a first ring gear R1 is normally connected to a third carrier C3; a second sun gear S2 is normally connected to a third sun gear S3; the third carrier C3 is normally connected to a fourth sun gear S4; and a second carrier C2 is normally connected to a fourth carrier C4. The automatic transmission includes: a first clutch CL1 for connecting and disconnecting between a third ring gear R3 and the fourth carrier C4; a second clutch CL2 for connecting and disconnecting between any two components of a second planetary gear set PL2; a first brake B1 for fixing the first ring gear R1; a second brake B2 for fixing the third ring gear R3; and a third brake B3 for fixing a first sun gear S1. An output part is normally connected to a fourth ring gear R4. |
