Patent ID: 8840518
Filing Date: 2014-09-23
Classification: F16H

Abstract:
1. A planetary gear train of an automatic transmission for vehicles, comprising: an input shaft adapted to receive engine torque; an output gear adapted to output changed torque; a compound planetary gear set formed by combining first and second planetary gear sets and including a first sun gear, a second sun gear, a common planet carrier, and a common ring gear as rotational elements thereof; a third planetary gear set including a third sun gear, a third planet carrier, and a third ring gear as rotational elements thereof; a first rotational member consisting of the second sun gear; a second rotational member consisting of the common planet carrier, and selectively connected to the input shaft so as to be operated as a selective input element or selectively connected to a transmission housing so as to be operated as a first selective fixed element; a third rotational member consisting of the common ring gear and connected to the output gear so as to be operated as a final output member; a fourth rotational member consisting of the first sun gear; a fifth rotational member consisting of the third ring gear and directly connected to the input shaft so as to be always operated as an input element; a sixth rotational member consisting of the third planet carrier; a seventh rotational member consisting of the third sun gear and operated as an output element or selectively connected to the transmission housing so as to be operated as a second selective fixed element; and six friction members including: wherein forward speeds achieved by operating three friction members among the six friction members comprise: