TRANSMISSION

PROBLEM TO BE SOLVED: To allow a compact configuration of a transmission with four or more planetary gear devices and six or more engagement elements coaxially disposed therein.SOLUTION: Respective gear ratios of four planetary gear devices 18, 20, 24, 28 are appropriately determined within a range of about 0.25-0.6, and thereby transmission gear ratios of nine forward drive speed positions can be set in well balanced steps while the planetary gear devices 18, 20, 24, 28 of relatively small size (small diameter) are used to compactly configure a transmission. Further, a pair of clutches C1 and C4 functioning as input clutches are disposed together on one end side in an axial direction, thereby providing a higher degree of gear train design freedom allowing two input paths to be provided along a shaft center, etc., and a frequency of use is limited with a power transmitted only at particular gear speed positions in each of the input paths, thereby providing advantages in terms of fatigue strength, allowing reduction in diameter, and allowing a compact configuration of a transmission 10 that can perform multi-step shifting to the nine forward drive speed positions.