Patent ID: 7077780

Claim:
A toroidal type continuously variable transmission comprising: input and output discs coaxially and rotatably arranged about a common axis, the input and output discs having respective toroidal concave surfaces which face each other; power rollers each having a rounded outer surface and being interposed between the toroidal concave surfaces of the input and output discs; a loading cam that presses the input disc against the power rollers by a force that is proposal to an input torque; trunnions each supporting the corresponding power roller in such a manner that the power roller is inclinable relative to a center of curvature of the input and output discs; and power roller bearings rotatably supporting the power rollers relative to the respective trunnions, wherein the following inequality is established for a curvature ratio (Ro/(2×R 22 )): Ro /(2 ×R 22)≦0.63 wherein: Ro: radius of curvature of the toroidal concave surface of each of the input and output discs, that is defined on a cross section of each of the input and output discs taken along the common axis, R 22 : radius of curvature of the rounded outer surface of each power roller, that is defined on a cross section of the power roller taken along the common axis.