PURPOSE: A power transfer device for an automatic transmission is provided to produce change gear steps of 10 forward steps and 1 backward step by installing and combining a plurality of planetary gear sets.;CONSTITUTION: An input element and a fixing element are two elements among four elements forming a first composite planetary gear set. A deceleration element and a counter-rotating element are the remaining two elements among the four elements forming the first composite planetary gear set. An output element is one element among four elements forming a second composite planetary gear set. A first friction element comprises a first clutch(71) transferring counter-rotating power outputted from the first composite planetary gear set to the second composite planetary gear set. A second clutch(72) and a third clutch(73) transfer deceleration power to the second composite planetary gear set.;COPYRIGHT KIPO 2012
展开▼