TOROIDAL TYPE CONTINUOUSLY VARIABLE TRANSMISSION AND RETAINER FOR ROLLING BEARING

PROBLEM TO BE SOLVED: To increase strength of a retainer for a thrust needle bearing used for a toroidal type continuously variable transmission. SOLUTION: The retainer 100 for the thrust needle bearing is formed by machining a sheet of sheet steel in a shape provided with a pocket passing through a sheet surface and then applying carbonitriding treatment, hardening and annealing on the same. Carbon (C) content ratio of a surface layer part of the retainer 100 is made to 0.5 wt.% or more and 1.4 wt.% or less, nitrogen (N) content ratio of the surface layer part is made to 0.05 wt.% or more and 0.5 wt.% or less, hardness of the surface layer part is made to Hv 550 or more and depth of a part where N content ratio is 0.05 wt.% is made 5 μm or more and 100 μm or less from the surface. COPYRIGHT: (C)2006,JPO&NCIPI