US Patent 7780566 8-speed automatic transmission for a vehicle

An eight-speed automatic transmission for a vehicle includes a single pinion planetary gear set, a double pinion planetary gear set, a compound planetary gear set, a first clutch, a second clutch, a third clutch, a fourth clutch, a first brake, a second brake, and a one-way clutch. The second clutch and the fourth clutch are disposed between the double pinion planetary gear set and the compound planetary gear set, and a center supporter is formed between the second clutch and the fourth clutch for smoothly supplying hydraulic pressure to the second clutch and the fourth clutch. Therefore, an input shaft may have a small diameter.