Patent ID: 9644714
Date: 2017-05-09
CPC Classifications: F16H

Claim:
1. A planetary gear train of an automatic transmission for a vehicle, the planetary gear train comprising: an input shaft receiving power from an engine; an output shaft outputting power changed in speed; a first planetary gear set which has first, second, and third rotating elements; a second planetary gear set which has fourth, fifth, and sixth rotating elements; a third planetary gear set which has seventh, eighth, and ninth rotating elements; a fourth planetary gear set which has tenth, eleventh, and twelfth rotating elements; and six control elements disposed between the rotating elements, and disposed at positions where the rotating elements are selectively connected to a transmission housing, wherein the input shaft is continuously connected with the eighth rotating element and simultaneously selectively connected with the fifth rotating element, the output shaft is continuously connected with the eleventh rotating element and simultaneously selectively connected with the ninth rotating element, the second rotating element is continuously connected with the sixth rotating element, the third rotating element is continuously connected to the seventh rotating element and the tenth rotating element, the fourth rotating element is continuously connected with the ninth rotating element, the first rotating element is selectively connected with the transmission housing, and gear shift stages for at least nine forward speeds and at least one reverse speed are implemented by operations of three control elements among the six control elements.