Patent ID: 9534670
Date: 2017-01-03
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 configured to output changed torque of the engine; 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 third planetary gear set including seventh, eighth, and ninth rotation elements; and a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, wherein the input shaft is directly connected to the eighth rotation element, the output shaft is directly connected to the eleventh rotation element, the first rotation element is directly connected to the seventh rotation element, the second rotation element is directly connected to the twelfth rotation element, the fifth rotation element is directly connected to the ninth rotation element, the sixth rotation element is directly connected to the eleventh rotation element, the third rotation element is selectively connected to the fourth rotation element, the first rotation element is selectively connected to the sixth rotation element and the input shaft respectively, the fifth rotation element and the ninth rotation element are selectively connected to the tenth rotation element, the second rotation element is selectively connected to a transmission housing, and the third rotation element is selectively connected to the transmission housing.