A single pinion type planetary gear unit and a double sun gear type
planetary gear units are coaxially arranged on different positions of a
given axis of an input shaft. First and second brakes are coaxially
arranged on different positions of the given axis. The first brake
selectively fixes a carrier of the double sun gear type planetary gear
unit and the second brake selectively fixes an outer one of the sun gears
of the double sun gear type planetary gear unit. First and second clutches
are coaxially arranged on different positions of the given axis to
transmit a speed changed rotation to rotational elements of the two
planetary gear unit to provide an associated automatic transmission with a
desired speed. The first clutch transmits the speed changed rotation to
the ring gear of the single pinion type planetary gear unit, and the
second clutch transmits the speed changed rotation to the sun gear of the
single pinion type planetary gear unit. The first and second clutches are
coaxially arranged in the vicinity of the single pinion type planetary
gear unit having the second clutch positioned in a space defined between
the first clutch and the input shaft.
