Patent ID: 7731623

Claim:
An automatic transmission, comprising: two clutches that are disposed such that they overlap in an axial direction and occupy different positions in a radial direction, each of the two clutches comprising: a clutch drum, a piston that forms a working fluid chamber for which a portion of the clutch drum serves as a cylinder, a plurality of friction plates that engage the clutch drum, and a cancel oil chamber that is disposed on a rear face side of the piston and that cancels a centrifugal oil pressure that acts on the working fluid chamber, wherein: the working fluid chamber and the cancel oil chamber of one clutch of the two clutches that is disposed outside in the radial direction are respectively disposed to the outside in the radial direction in relation to the working fluid chamber and the cancel oil chamber of the other clutch of the two clutches, and oil is supplied to the cancel oil chamber of the one clutch of the two clutches that is disposed to the outside in the radial direction through a gap between the clutch drum of the other clutch of the two clutches and the clutch drum of the one clutch of the two clutches that is disposed to the outside in the radial direction.