Planetary gear train for automatic transmission of vehicle

摘要

A planetary gear train for an automatic transmission of a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting changed torque of the engine, 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 rotation shaft, a third rotation shaft selectively connected to the transmission housing, a fourth rotation shaft, directly connected to the input shaft, a fifth rotation shaft including the second ring gear and the third and fourth sun gears, a sixth rotation shaft selectively connected to the second rotation shaft, a seventh rotation shaft selectively connected to the second and fourth rotation shafts, an eighth rotation shaft selectively connected to the sixth rotation shaft, and directly connected to the output shaft; and six friction elements.

主权项

1. A planetary gear train for an automatic transmission of a vehicle, comprising:
an input shaft receiving torque of an engine; an output shaft outputting changed torque of the engine; a first planetary gear set including a first sun gear, a first planet carrier, and a first ring gear; a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear; a third planetary gear set including a third sun gear, a third planet carrier, and a third ring gear; a fourth planetary gear set including a fourth sun gear, a fourth planet carrier, and a fourth ring gear; a first rotation shaft including the first and second sun gears and selectively connected to a transmission housing; a second rotation shaft including the first planet carrier; a third rotation shaft including the first and fourth ring gears and selectively connected to the transmission housing; a fourth rotation shaft including the second planet carrier and directly connected to the input shaft; a fifth rotation shaft including the second ring gear and the third and fourth sun gears; a sixth rotation shaft including the third planet carrier and selectively connected to the second rotation shaft; a seventh rotation shaft including the third ring gear and selectively connected to the second and fourth rotation shafts; an eighth rotation shaft including the fourth planet carrier and selectively connected to the sixth rotation shaft, and directly connected to the output shaft; and six friction elements disposed to selectively connect the rotation shafts to each other and selectively connect the rotation shafts to the transmission housing.