Automatic transmission for vehicles

摘要

A vehicular automatic transmission, for establishing a plurality of forward gear stages, includes: a transmission case; an input shaft; a transmission mechanism connected to the input shaft and including a plurality of transmission elements; an output shaft connected to the transmission mechanism; a clutch drivably connecting any one of the input shaft and the transmission elements individually; and a hydraulic servo for applying the clutch responsive to an oil pressure. The transmission case encloses the transmission mechanism, the clutch and the hydraulic servo, and includes axial end walls, on one of which is formed a stationary cylinder for the hydraulic servo. A piston is slidably mounted in the cylinder and together with the cylinder, defines an oil chamber for receipt of the actuating oil pressure. A bearing is arranged between the piston and the clutch for transmitting the thrust force from the piston to the clutch, while allowing relative rotation between the piston and the clutch. The clutch includes a hub with an outer cylindrical surface splined to a friction plate assembly and a rim radially spaced from the hub with the friction plate assembly splined to its inner cylindrical surface. The input shaft is connected to the hub whereas one of the transmission elements is connected to the rim.