PLANETARY GEAR TRANSMISSION

摘要

A planetary gear transmission typically for use on automobiles has first, second, and third planetary gear trains arranged coaxially with each other and each having elements including a sun gear, a carrier, and a ring gear. Two of the elements of each of the first, second, and third planetary gear trains are directly or disengageably coupled to elements of the other planetary gear trains. The transmission also has three clutch means and two brake means for selectively establishing a power transmitting path from an input shaft to an output gear member through the first, second, and third planetary gear trains. At least one of the first, second, and third planetary gear trains comprises a double-pinion planetary gear train, one of the sun gear and the carrier of the double-pinion planetary gear train being coupled to the input shaft and the other being nonrotatably fixed. The elements of the first, second, and third planetary gear trains are corotatably coupled into first, second, third, fourth, and fifth rotational members in a speed diagram, the third and fifth rotatable members being coupled to the input member, the fourth rotational member being coupled to the output member. The carrier of the double-pinion planetary gear train may be coupled to the input shaft, and the sun gear thereof may be nonrotatably fixed.