To suppress a torque loss to improve the efficiency of torque transmission in a traction drive type reduction gear.
A traction drive type reduction gear is configured such that a rotating roller 14 and a planetary roller 21 which are indirectly brought into rotational contact with an input shaft 1 and a rotating ring 3 are incorporated between the input shaft 1 and the rotating ring 3, and when the input shaft 1 is rotated, the rotating ring 3 is rotated in the reverse direction according to the rotation of the rotating roller 14 and, at the same time, the revolution of the planetary roller 21 is transmitted to an output shaft 2 via a carrier 6, wherein the rotating roller 14 is brought into rolling contact with an inner wall of a recessed engagement part 8a of a cover (stationary member) 8 via a rolling bearing 16 in the rotation direction of the input shaft 1, and meanwhile, the planetary roller 21 is brought into rolling contact with the inner wall of a recessed engagement part 6a of the carrier 6 via a rolling bearing 23 in the revolution direction and, thereby, heat generation due to sliding between the respective members is prevented to suppress a torque loss.
Higashio Masahiro
Takayoshi Tagawa