Patent ID: 6251041
Filing Date: 2001-06-26
Classification: F16C,F16H

Abstract:
A toroidal type continuously variable transmission, comprising:first and second disks concentrically disposed on each other and rotatably supported about a mutual central axis, said first and second disks respectively having circularly concave surfaces, which are opposed to each other;a trunnion swingable about a pivot shaft situated at a torsional relation with respect to the center axis of said first and second disks;a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, said displacement shaft being rotatably supported on said trunnion through said support shaft portion, said pivot shaft portion being projected from an inner surface of said trunnion;a power roller nipped between said first and second disks in such a manner as to be rotatably supported on a periphery of said pivot shaft portion, a peripheral surface of said power roller having a circular convex surface contactable with said circularly concave surfaces of said first and second disks;a thrust ball bearing disposed for bearing a thrust load exerted on said power roller and allowing said power roller to rotate, said thrust ball bearing having an outer ring; anda thrust needle bearing interposed between said outer ring of the thrust ball and said trunnion, for bearing a thrust load exerted on said outer ring of the thrust ball bearing by said power roller and allowing said outer ring of the thrust ball bearing to swing about said support shaft portion, said thrust needle bearing being provided with a thrust needle roller and a retainer rollably retaining said thrust needle roller,wherein said retainer of the thrust needle bearing is of a single plate, is carbonitrided, and has a surface hardness Hv of 550 or more;wherein said retainer has a core portion hardness Hv of 350 to 500.