GEAR TRAIN IN AN AUTOMATIC TRANSMISSION FOR VEHICLES

摘要

A gear train for automatic transmission for vehicle is provided to simplify a composition and to enhance power transmission performance and fuel efficiency by forming eight shift gears and one reverse gear with four clutches and two brakes. A gear train of an automatic transmission for vehicle includes a first planetary gear set and a frictional member. The first planetary gear set is composed of a double pinion planetary gear set having three rotational elements. A first rotational element includes a first sun gear. The first gear is directly connected to a transmission housing and is operated as a fixing element. A second rotational element is composed of a first ring gear for forming a first intermediate output path. A third rotational element includes a first planetary carrier. The first planetary carrier is directly connected with an input shaft in order to form an input path and a second intermediate output path for outputting an input. A frictional member is composed of a clutch and a brake in order to connect variably the rotational members of the first and second planetary gear sets with each other or with the transmission housing.