Patent ID: 9546712
Date: 2017-01-17
CPC Classifications: F16H

Claim:
1. A planetary gear train of an automatic transmission for a vehicle comprising: an input shaft receiving rotary power of an engine; an output shaft outputting the rotary power with rotary speed changed; 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 rotating shaft including the first sun gear and the third sun gear and operating continuously as an input element by being directly connected with the input shaft; a second rotating shaft including the first planetary carrier and selectively connected with a transmission housing; a third rotating shaft including the first ring gear and the second planetary carrier; a fourth rotating shaft including the second sun gear and selectively connected with the transmission housing; a fifth rotating shaft including the second ring gear and the fourth sun gear and selectively connected with the second rotating shaft; a sixth rotating shaft including the third planetary carrier and the fourth ring gear and operating continuously as an output element by being directly connected with the output shaft; a seventh rotating shaft including the third ring gear; an eighth rotating shaft including the fourth planetary carrier and selectively connected with the first, the fourth, and the seventh rotating shafts; and six friction elements disposed at portions selectively connecting the rotating shafts or selectively connecting the rotating shafts and the transmission housing respectively.