Patent ID: 6932736

Claim:
A toroidal continuously variable transmission comprising: input and output disks coaxially arranged with each other and having respective toroidal grooves opposed to each other; a plurality of power rollers interposed between the toroidal grooves of the input and output disks under axial preload for power transmission; a plurality of trunnions rotatably supporting the respective power rollers to permit tilting motions of the power rollers about trunnion axes for ratio changing; each of the power rollers comprising: (a) an inner race that transmits power input to the input disk into the output disk via a traction oil film formed between each of the power rollers and each of the input and output disks, using a shearing force in the traction oil film; (b) an outer race that is supported by the trunnion associated therewith; and (c) a power roller bearing that rotatably supports the inner race to permit relative rotation of the inner race to the outer race; the power roller bearing comprising a tapered roller bearing, the tapered roller bearing including: (a) an inner raceway surface formed on the inner race; (b) an outer raceway surface formed on the outer race; (c) a plurality of rolling elements, each sandwiched between the inner and outer raceway surfaces and having a frusto-conical shape in axial cross section; and (d) a collared portion that guides the rolling elements; the tapered roller bearing receiving both a radial load and a thrust load acting on the inner race; all of the inner raceway surface located to be offset from a line of action, common to a radial component of a contact pressure acting on a contact point between the inner race and the input disk and a radial component of a contact pressure acting on a contact point between the inner race and the ouput disk, toward the outer race; and a contact angle of the inner raceway surface dimensioned to be within a predetermined contact angle range of 50° to 75°.