| 摘要 |
A 7-shift power train of an automatic transmission is provided to perform easily a two-stage skip operation and a three-stage skip operation by using four single pinion planetary gear sets, three clutches, and three brakes. A 7-shift power train includes four single pinion planetary gear sets(PG1,PG2,PG3,PG4), three clutches, and three brakes. A second sun gear(S2) is connected to a third sun gear(S3). The third sub gear is connected to a fourth sun gear(S4). A second ring gear(R2) is connected to a third planetary carrier(PC3). The third planetary carrier is connected to a fourth planetary carrier(PC4). A first ring gear(R1) is connected to an input shaft(10). A first sun gear(S1) is connected directly to a transmission housing(30). A second clutch(C2) is inserted into the second sun gear so that a first planetary carrier(PC1) and a third brake(B3) are variably connected to the transmission housing. A second brake(B2) is inserted into a second planetary carrier(PC2) so that the second ring gear is variably connected through a first brake(B1) and a one-way clutch(F1) to the transmission housing. A third clutch(C3) is inserted into the fourth planetary carrier so that a fourth ring gear(R4) is variably connected through a first clutch(C1) and the third clutch to the input shaft. A third ring gear(R3) is directly connected to an output shaft(20). |
