Patent ID: 7674200

Claim:
A power train of an automatic transmission, comprising: an input shaft; an output gear; a transmission case; a speed shift unit comprising a first operational member that is fixedly connected to the input shaft, a second operational member that is selectively coupled to the input shaft, a third operational member that is fixedly connected to the transmission case, a fourth operational member that generates a reverse rotational speed by operations of the first and third operational members, and a fifth operational member that is selectively coupled to the fourth operational member and receives the reverse rotational speed from the fourth operational member, or generates a reduced rotational speed by operations of the second and third operational members; an output unit comprising a sixth operational member that is fixedly connected to the fifth operational member, selectively receives the reverse rotational speed from the fourth operational member or the reduced rotational speed from the fifth operational member, and is selectively coupled to the transmission case, a seventh operational member that is selectively coupled to the input shaft and selectively coupled to the transmission case, an eighth operational member that is selectively coupled to the input shaft, and a ninth operational member that always operates as an output member by being fixedly connected to the output gear, wherein the output unit generates eight forward speeds and one reverse speed at the ninth operational member by operations of the sixth, seventh, and eighth operational members; a first clutch for selectively coupling the eighth operational member to the input shaft; a second clutch for selectively coupling the fourth operational member to the fifth operational member; a third clutch for selectively coupling the second operational member to the input shaft; a fourth clutch for selectively coupling the seventh operational member to the input shaft; a first brake for selectively stopping the seventh operational member; and a second brake for selectively stopping the sixth operational member.