| 摘要 |
PROBLEM TO BE SOLVED: To provide a disc of a toroidal type continuously variable transmission in which a production cost can be reduced and a long service life can be attained. SOLUTION: A disc 1 is provided with a traction surface 4 having a sectional area of circular arc concave between an end 2 having a small diameter and an end 3 having a big diameter. A hole is formed, which extends to an edge surface of the end 3 having a big diameter, at the central portion of the edge surface of the end 2 having a small diameter, and an inner peripheral surface of the hole is made to be an inner diameter surface 5. The disc 1 is constituted such that 'a metal flow 6 along the disc surface' exists at least traction surface 4, of metal flows 6 existing at the disc 1, in the case where the metal flow 6 having a position relationship such that an angleθof the metal flow 6 of the traction surface 4 side with a tangent of the traction surface 4 becomes 30 deg. or less is defined as 'a metal flow 6 along the disc surface'. |
