Patent ID: 9625011
Date: 2017-04-18
CPC Classifications: F16H

Claim:
1. A planetary gear train of an automatic transmission for a vehicle, comprising: an input shaft receiving torque of an engine; an output shaft outputting changed torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a compound planetary gear set formed by combining third and fourth planetary gear sets and including seventh, eighth, ninth, and tenth rotation elements; a fifth planetary gear set including eleventh, twelfth, and thirteenth rotation elements; and six friction elements, including first, second, third, and fourth clutches, and first and second brakes, wherein the input shaft is continuously connected to the fifth rotation element, the output shaft is continuously connected to the twelfth rotation element, the ninth rotation element is selectively connected to the input shaft through the first clutch, the tenth rotation element is continuously connected to the eleventh rotation element, the seventh rotation element is continuously connected to the sixth rotation element, the seventh rotation element is selectively connected to the twelfth rotation element so as to achieve a fourth forward speed stage, and the eighth rotation element is selectively connected to the twelfth rotation element so as to achieve a sixth forward speed stage, an eighth forward speed stage, and a reverse speed stage, wherein at least three friction elements among the six friction elements are operated at each speed stage.