Oil pressure clutch mechanism for an automatic transmission

摘要

An oil pressure clutch mechanism of an automatic transmission is comprised of at least two clutches interposed coaxially in a front drum. An oil circuit for controlling the clutches is formed in the front drum in relation to an oil circuit in an oil pump cover. The oil circuit includes circular oil grooves formed between an outer face of the oil pump cover and an inner face of the drum. A circular drain groove is disposed axially between the circular oil grooves to receive oil leaked therefrom. A drain passage is formed in the front drum for conducting leaked oil from the drain groove to a location external of the front drum. The outlet end of the drain groove is spaced farther from the axis than is the inlet end thereof, whereby leaked oil is discharged through the oil drain passage under the influence of centrifugal force.