| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw which reduces weight and size of a CVT without deteriorating transmission efficiency, and the CVT provided with the ball screw. SOLUTION: In the belt type continuously variable transmission, a transmission belt 1 is wound between belt receiving faces 2a and 3a respectively facing a fast pulley 2 provided on a rotary shaft 4 and a movable pulley 3, and a winding diameter of the transmission belt 1 is steplessly changed by axially moving the movable pulley 3 by the ball screw 20. The movable pulley 3 is axially moved by: fixing rotation and axial movement of a nut 22 of the ball screw 20; connecting a hollowly formed screw shaft 21 to the movable pulley 3 so it can rotate and axially move; covering an end part of the screw shaft 21 in a side opposite to the movable pulley 3 by an end part of the nut 22; and rotary-driving the screw shaft 21. |
