| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic transmission capable of establishing speed change gears of ten forward gears or more without increasing a friction loss.SOLUTION: An automatic transmission includes first to fourth planetary gear mechanisms PGS1-PGS4, first to third clutches C1-C3, and first to third brakes B1-B3. Respective elements of the second and third planetary gear mechanisms PGS2 and PSG3 constitute first to fourth rotation elements Y1-Y4. A first element Sa is connected to an input shaft 2, a fourth element Rd is connected to an output member 3, a third element Ra is connected to a sixth element Sd, and the third rotation element Y3 is connected to a fifth element Cd. The first clutch C1 freely connects the first element Sa to the second rotation element Y2, the second clutch C2 freely connects the first element Sa to the first rotation element Y1, and the third clutch C3 freely connects a second element Ca to the fourth rotation element Y4. The first brake B1 freely fixes a first connection body Ra-Sd, the second brake B2 freely fixes the second rotation element Y2, the third brake B3 freely fixes the second element Ca, and the fourth brake B4 freely fixes the first rotation element Y1, to a transmission case 1 respectively. |
