Patent ID: 7914413
Filing Date: 2011-03-29
Classification: F16H

Abstract:
1. An automatic transmission, comprising: an input shaft; a speed-reduction planetary gear that can reduce a rotation of the input shaft and output a reduced rotation; a planetary gear unit that is disposed coaxially to the speed-reduction planetary gear and includes a first rotating element, a second rotating element, a third rotating element, and a fourth rotating element; a first clutch that inputs the reduced rotation to the fourth rotating element; a second clutch that inputs the rotation of the input shaft to the second rotating element; a third clutch that inputs the reduced rotation to the first rotating element, the third clutch including a hydraulic servo with a piston member, a clutch drum and sealing members; a fourth clutch that inputs the rotation of the input shaft to the first rotating element, the fourth clutch including a hydraulic servo with a piston member, a clutch drum and sealing members; a first brake that holds a rotation of the first rotating element stationary; a second brake that holds a rotation of the second rotating element stationary; an output member that is linked to the third rotating element, wherein: