DISK OF TOROIDAL CONTINUOUSLY VARIABLE TRANSMISSION AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a disk for a toroidal type continuously variable transmission capable of machining a traction surface in a short time and suppressing the dispersion of an effective traction range. SOLUTION: This disk 12a for the toroidal type continuously variable transmission is provided with the traction surface T contacting with a power roller and formed with a recess portion 76 whose wall thickness is reduced with a step difference 75 set to a boundary in the end of the traction surface in the side of a small diameter portion 70 of the disk 12a. The manufacturing method of this disk 12a includes a process of forming the recess portion 76 in the end of the traction surface by a lathe machining before the heat treatment, a process of finishing the traction surface T into a prescribed curvature by a hard turning process after the heat treatment, and a process of performing superfinishing of the traction surface T.