Automatic transmission

An automatic transmission comprising:

• a Ravigneaux planetary gear set including a front sun gear, a rear sun gear, a ring gear, a long pinion gear engaged with the front sun gear and the ring gear, a short pinion gear engaged with the rear sun gear and the long pinion gear, and a common carrier rotatably supporting the long pinion gear and the short pinion gear;
• an input member arranged to input a rotation of a driving source;
• a first friction engagement element selectively connecting the input member and the front sun gear;
• a second friction engagement element selectively connecting the input member and the common carrier;
• a third friction engagement element selectively fixing the rear sun gear to an automatic transmission case;
• a fourth friction engagement element selectively fixing the front sun gear to the automatic transmission case;
• a fifth friction engagement element selectively fixing the common carrier to the automatic transmission case;
• an output member constantly connected with the ring gear,
• the automatic transmission being configured to attain four forward speeds and one reverse speed by simultaneous engagement of two friction engagement elements selected from the first to fifth friction engagement elements,
• the first friction engagement element, the second friction engagement element, and the fifth friction engagement element being disposed on a front side which is nearer to the driving source than is the output member,
• the third friction engagement element and the fourth friction engagement element being disposed on a rear side which is farther from the driving source than is the output member, and
• a first drum member that includes an inner circumference on which the second friction engagement element is disposed, and an outer circumference on which the fifth friction engagement element is disposed, and that is arranged with a front carrier plate located at a front end portion of the common carrier.