Patent ID: 7575530

Claim:
A planetary roller transmission device, comprising: an input shaft which is provided rotatably on an axis; an output shaft provided on the same axis as the input shaft; a sun roller provided on the input shaft; a plurality of planetary rollers which are rollable around an outer periphery of the sun roller, each of the planetary rollers being formed with a taper portion; an output ring which is provided integrally with the output shaft, and inside which the planetary rollers roll; and a shift ring with which the taper portion provided on each of the planetary rollers internally and rollably contacts, and which is provided to be movable in only along the axis of the input shaft and the output shaft, wherein the sun roller, planetary rollers, output ring and shift ring being disposed so that the sun roller contacts the planetary rollers by pressing the planetary rollers in an outer direction away from the axis at a position located between a first position at which the output ring contacts the planetary roller, and a second position at which the shift ring contacts the planetary roller.