To provide a rolling element for a toroidal type continuously variable transmission and a working method therefor, in which machining cost can be reduced, a residual compressive stress layer of which the internal depth is deep is added to a surface layer of a ball bearing groove face of a power roller, rolling fatigue-bearing life is prolonged, the ball bearing groove face is formed to be in a shape of a highly accurate circular arc.
The power roller as a rolling element for a toroidal type continuously variable transmission has the ball bearing groove face, of which the surface is worked by cutting work, burnishing work, and super finishing work, of which the roughness is 0.04 μmRa or less, a maximum residual compressive stress is -1000 MPa or less, and a residual compressive stress layer is formed from the surface to the internal depth of 0.2 mm.
TANAKA KAZUHIKO
NAKAMURA YOJI
UEHARA YOSHITAKA
