To prevent an increase in contact pressure as a result of receiving a biased thrust load by a thrust bearing of a roller, when a unit housing is deformed by radial pressing reaction force between rollers.

Rotation of a first roller 21 which rotates together with an input shaft 12, is transmitted to a second roller 22 which is pressed against an outer circumference, and taken out from an output shaft 13. Shafts 12 and 13 are bent by the radial pressing reaction force between the rollers, and the unit housing 11 is elastically deformed so that sidewall center sections 11c and 11d can approach each other. Thereby, thrust in a compression direction tends to concentrate in a small area within a circle region of the thrust bearings 23 and 25 facing the center sections 11c and 11d of the unit housing sidewall. Then, thrust buffer members 31 and 32 are inserted in a thrust transmission path between the thrust bearings 23 and 25 and the unit housing 11, and a thrust load is dispersed in a wide area such as γ' or δ', to reduce the contact pressure.