Patent ID: 6051080
Filing Date: 2000-04-18
Classification: C23C,F16H,Y10S

Abstract:
A rolling element used for a toroidal-type continuously variable transmission, said rolling element comprising:an input side disk adapted to be disposed on an input shaft of said transmission;an output side disk adapted to be disposed on an output shaft of said transmission; anda power roller for transmitting motive power of the input shaft to the output shaft, while engaging both said input side disk and said output side disk, said power roller being adapted to be pivotably attached to a trunnion through a pivot,wherein said power roller is prepared by a method comprising the sequential steps of:(a) subjecting a perform of said power roller to a surface-hardening process which is one of a carburizing process and a carbonitriding process, thereby to prepare a surface-hardened preform; and(b) subjecting said surface-hardened preform to a grinding process, thereby to prepare said power roller,wherein said power roller has first and second sides which are opposed to each other in an axial direction thereof, said first side having a groove for receiving a bearing that is adapted to be interposed between said power roller and said trunnion, a surface of said groove having a carbon concentration which is higher than that of a surface of said second side, said power roller prepared by said method having a hardened outer layer having first and second portions which are disposed on said first and second sides respectively, said first portion of said hardened outer layer being defined as having an exterior boundary which is said surface of said groove, said second portion of said hardened outer layer being defined as having an exterior boundary which is said surface of said second side, said first portion of said hardened outer layer having an effective depth which is thicker than that of said second portion thereof.