Patent ID: 7273437

Claim:
A continuously variable transmission comprising: a casing; a rotation shaft rotatably supported in the casing; a pair of outer side disks each having a side face of which section is in arc shape, supported on the rotation shaft at two positions which are separated from each other in the axial direction so that the side faces thereof oppose to each other, wherein the outer side disks rotate in synchronism with the rotation shaft; an inner side disk having two side faces of which sections are in arc shape, rotatably supported on a substantially middle portion of the rotation shaft so that the two side faces thereof oppose respective ones of the side faces of the outer side disks, and rotating on the rotation shaft; pluralities of supporting members disposed between the two side faces of the inner side disk and the side faces of the outer side disks, respectively, and swinging on a pivot shaft disposed to be twisted relative to the rotation shaft; and pluralities of power rollers rotatably supported on the respective supporting members, each having a spherical projected face of which a peripheral surface rollably contacts with one of the side faces of the inner side disk and one of the side faces of the outer side disks, wherein an outer peripheral face of the inner side disk is provided with a detected portion for detecting rotation of the inner side disk, wherein pluralities of recess grooves are provided intermittently in a circumferential direction so as to be inclined to a center axis of the inner side disk as the detected portions, wherein both end portions of pairs of projected portions, which are defined between the respective recess grooves provided at the outer peripheral face, overlap each other in the axial direction of the inner side disk, and top portions of the projected portions form a single cylindrical face when the inner side disk is viewed from the axial direction.