Supporting device of a planetary ring gear for an automatic transmission

摘要

An automatic transmission comprising a single planetary gear unit and a dual planetary gear unit has an output member located in its center so that the output member encloses an input shaft. In the case of a three speed automatic transmission mechanism, a first clutch located around a ring gear of the single planetary gear unit connects the input shaft to this ring gear. In the case of a four speed automatic transmission mechanism, a third clutch which actuates overdrive is additionally located axially outside the first clutch for connecting the input member to a ring gear of the dual planetary gear unit. A sun gear common to both planetary units is connected to the input shaft by a second clutch. This clutch has a drum portion upon which a band may act to brake the sun gear.