Continuously variable transmission and bicycle

Abstract

A continuously variable transmission includes an input rotor, an output rotor, a plurality of planetary rollers, a guide member, a movable ring, and an elastic member. The input rotor is arranged to rotate about a main axis at a rotation rate before a speed change. The output rotor is arranged to rotate about the main axis at a rotation rate resulting from the speed change. The planetary rollers are arranged around the main axis, and each planetary roller is capable of rotating about a rotation shaft. The guide member is arranged to restrict positions of both end portions of the rotation shaft. The movable ring is capable of rotating about the main axis between the main axis and the planetary rollers. The movable ring is annular, and is capable of moving in an axial direction. The elastic member is capable of expanding and contracting in the axial direction. Each planetary roller includes a first slanting surface, a second slanting surface, and an annular recessed portion or annular projecting portion. The guide member is arranged to hold the end portions of the rotation shaft at different circumferential positions such that each end portion of the rotation shaft is capable of shifting a position thereof in a radial direction with respect to the main axis. The elastic member is arranged to apply a pressure to the movable ring in the axial direction.