PURPOSE: To prevent lubricating oil in a torque cam groove from leaking out to the outside by connecting a torque cam collar to a movable sheave of a speed change pulley so as to form the torque cam groove on an internal surface of this torque cam collar and also to coat the torque cam collar with an inner ring of a bearing.

CONSTITUTION: A speed change pulley 6 having fixed and movable sheaves 7, 8 is supported to a point end part of a rotary shaft 1, and a cam mechanism 21, for bringing the movable sheave 8 near to and separating it from the fixed sheave 7, having a cylindrical cam 23 rotated by operating a turning lever 25, is provided in a back surface side of the movable sheave 8. In a speed change gear thus constituted, a boss part 9 of the movable sheave 8 is constituted of ring members 10, 11 and a torque cam collar 14 integrally arranged between both the members 10, 11, to form a pair of helical torque cam grooves 15 on an internal surface of the collar 14, and torque pins 16 protrusively provided in a sleeve 4 are respectively engaged with the torque cam grooves. Width of an inner ring 22a of a bearing 22 on the boss part 9 of the movable sheave 8 is increased so as to cover the collar 14.