Planetary gear train of automatic transmission for vehicle

摘要

A planetary gear train of an automatic transmission for a vehicle may include: an input shaft, an output shaft disposed in parallel with the input shaft, a first planetary gear set disposed on the input shaft, a second planetary gear set disposed on the output shaft, a third planetary gear set disposed on the output shaft, three transfer gears forming an externally-meshed gears, and frictional elements selectively interconnecting rotation elements or selectively connecting the rotation elements to a transmission housing. The first planetary gear set includes a first ring gear, a first planet carrier, and a first sun gear. The second planetary gear set includes a second sun gear, a second planet carrier, and a second ring gear. The third planetary gear set includes a third sun gear, a third planet carrier, and a third ring gear.

主权项

1. A planetary gear train of an automatic transmission for a vehicle, comprising:
an input shaft receiving torque of an engine; an output shaft disposed in parallel with the input shaft; a first planetary gear set disposed on the input shaft, the first planetary gear set including a first ring gear directly connected to the input shaft so as to be always operated as an input element, a first planet carrier selectively operated as an output element, and a first sun gear selectively operated as an output element and a fixed element, as rotation elements thereof; a second planetary gear set disposed on the output shaft, the second planetary gear set including a second sun gear connected to the first planet carrier through an externally-meshed gear, a second planet carrier selectively connected to the first sun gear through an externally-meshed gear, and a second ring gear operated as an output element, as rotation elements thereof; a third planetary gear set disposed on the output shaft, the third planetary gear set including a third sun gear selectively connected to the first ring gear and the input shaft through an externally-meshed gear, a third planet carrier directly connected to the second ring gear and the output shaft, and a third ring gear selectively connected to the first sun gear through an externally-meshed gear and selectively connected to the second planet carrier as rotation elements thereof; three transfer gears forming the externally-meshed gears; and frictional elements selectively interconnecting the rotation elements or selectively connecting the rotation elements to a transmission housing.