PLANETARY GEAR TRAIN OF AUTOMATIC TRANSMISSION FOR VEHICLES

摘要

Disclosed is a planetary gear train of an automatic transmission for a vehicle. According to an embodiment of the present invention, the planetary gear train of an automatic transmission for a vehicle comprises: an input shaft into which power of an engine is transmitted; an output shaft outputting shifted power; a first planetary gear set; a second planetary gear set; a third planetary gear set; a fourth planetary gear set; a first rotation shaft selectively connected to a transmission housing; a second rotational shaft directly connected to the input shaft; a third rotational shaft; a fourth rotational shaft; a fifth rotational shaft selectively connected to the first rotational shaft and the second rotational shaft; a sixth rotational shaft directly connected to the output shaft, and selectively connected to the fourth rotational shaft; a seventh rotational shaft selectively connected to the transmission housing; an eighth rotational shaft selectively connected to the fifth rotational shaft; and six friction elements.