| 摘要 |
PURPOSE: A power train of an automatic transmission is provided to improve dynamic power transfer performance by increasing the number of transmission steps. CONSTITUTION: A power train of an automatic transmission includes a first planetary gear set(PG1) and a second planetary gear set(PG2). The first planetary gear set has a first, a second and a third operation member(S1,PC1,R1). The first operation member is fixed to a transmission case(30). The second operation member is selectively fixed to the transmission case. The second planetary gear set has a fourth, a fifth and a sixth operation member(S2,PC2,R2). The fourth operation member is selectively connected to the second operation member. The fifth operation member is selectively fixed to the third operation member. The power train of the automatic transmission further includes a third planetary gear set(PG3) and a friction member. The third planetary gear set has a seventh, an eighth and a ninth operation member(S3,PC3,R3). The eighth operation member is fixed to the sixth operation member. The ninth operation member is fixed to the transmission case. Friction members connect operation members of the first, the second and the third planetary gear set to an input axis(10), other operation members, the transmission case or an output axis(20). |
