Patent ID: 7517297

Claim:
A planetary-gear-type multistage transmission comprising: a first transmission portion including a first intermediate output path for outputting rotations of an input member at a fixed transmission ratio determined in advance, and a second intermediate output path for outputting rotations of said input member after reducing the rotations at a greater transmission ratio than said first intermediate output path; and a second transmission portion having a single-pinion type second planetary gear set, a single-pinion type third planetary gear set, and a double-pinion type fourth planetary gear set, in which a first rotary element being composed of a sun gear of said second planetary gear set and a sun gear of said third planetary gear set connected to each other, a second rotary element being composed of a carrier of said second planetary gear set, a carrier of said third planetary gear set and a carrier of said fourth planetary gear set connected to each other, a third rotary element being composed of a ring gear of said second planetary gear set, a fourth rotary element being composed of a ring gear of said third planetary gear set and a ring gear of said fourth planetary gear set connected to each other, a fifth rotary element being composed of a sun gear of said fourth planetary gear set; and said first rotary element being selectively brought to a stationary state by a first brake, said second rotary element being selectively brought to a stationary state by a second brake, said third rotary element being selectively brought to a stationary state by a third brake, said fifth rotary element being selectively connected to said second intermediate output path via a first clutch, said first rotary element being selectively connected to said second intermediate output path via a second clutch, said second rotary element being selectively connected to said first intermediate output path via a third clutch; and having a fourth clutch for causing said five rotary elements to rotate integral with said first intermediate output path by being engaged with said third clutch; and outputting rotations by said fourth rotary element being connected to an output member; wherein a plurality of gear stages are established by changing engagement and disengagement of said clutches and brakes.