AUTOMATIC TRANSMISSION

摘要

An automatic transmission in which sufficient centrifugal hydraulic pressure in a cancel hydraulic chamber is secured and in which hydraulic oil is quickly discharged to appropriately maintain clutch timing. One clutch (C3) is placed on the outer diameter side of the other clutch (C4) so that they are axially overlapped on each other. Hydraulic pressure acts on a hydraulic servo (20) of the clutch (C3) through an oil hole (b) formed in a clutch drum (22). Oil is supplied from a supply hole (a) of a boss section (22c) through a space (A) to a cancel hydraulic chamber (28) formed on the rear surface of the hydraulic servo, and the oil is released outward from a discharge hole (e) of the boss section (22c) through a groove (g) of a sleeve (81).