Patent ID: 9587718
Date: 2017-03-07
CPC Classifications: F16H

Claim:
1. A planetary gear train of an automatic transmission for a vehicle comprising: an input shaft to receive torque of an engine; an output shaft to output changed torque of the engine; a first planetary gear set including a first rotation element, a second rotation element, and a third rotation element; a second planetary gear set including a fourth rotation element, a fifth rotation element, and a sixth rotation element; a third planetary gear set including a seventh rotation element, an eighth rotation element, and a ninth rotation element; and a fourth planetary gear set including a tenth rotation element, an eleventh rotation element, and a twelfth rotation element, wherein the input shaft is directly connected to the first rotation element, the output shaft is directly connected to the twelfth rotation element, the second rotation element is directly connected to the sixth rotation element and the ninth rotation element, the fifth rotation element is directly connected to the eleventh rotation element, the eighth rotation element is directly connected to the tenth rotation element, and the second rotation element is selectively connected to a transmission housing.