Patent ID: 9482320
Filing Date: 2016-11-01
CPC Classification: F16H

Claim Text:
1. A planetary gear train of an automatic transmission for vehicles, comprising: an input shaft receiving torque of an engine; an output shaft outputting changed torque; a first planetary gear set including a first sun gear, a first planetary carrier, and a first ring gear; a second planetary gear set including a second sun gear, a second planetary carrier, and a second ring gear; a third planetary gear set including a third sun gear, a third planetary carrier, and a third ring gear; a fourth planetary gear set including a fourth sun gear, a fourth planetary carrier, and a fourth ring gear; a first rotational shaft including the first sun gear and selectively connected to a transmission housing; a second rotational shaft including the first planetary carrier and directly connected to the input shaft; a third rotational shaft including the first ring gear, second sun gear, and fourth sun gear, and selectively connected to the transmission housing; a fourth rotational shaft including the second planetary carrier and selectively connected to the first rotational shaft or the second rotational shaft; a fifth rotational shaft including the second ring gear and the third sun gear; a sixth rotational shaft including the third planetary carrier and the fourth ring gear and selectively connected to the fifth rotational shaft; a seventh rotational shaft including the fourth planetary carrier and directly connected to the output shaft; an eighth rotational shaft including the third ring gear and selectively connected to the first rotational shaft; and six friction elements selectively connecting the rotational shafts and the transmission housing.