SHELL-TYPE RADIAL NEEDLE BEARING OUTER RING AND METHOD FOR MANUFACTURING SAME

摘要

In a shell-type radial needle bearing outer ring (6a) having a cylindrical shape with a bottom, without incurring a cost increase, the bottom plate portion (9a) thereof and the continuous portion between the bottom plate portion (9a) and the cylindrical portion (8a) are improved in fatigue strength, and the anti-rust performance of the outer ring (6a) and the performance for retaining the outer ring (6a) are also improved. After an intermediate material (35) having a cylindrical portion and a bottom plate portion is obtained from a metal material, shot peening is performed on the intermediate material (35) to produce a residual compressive stress in the outer surface side surfaces and surface layer portions of the cylindrical portion (8a) and the bottom plate portion (9a). The residual compressive stress in the outer surface side surface layer portions is made larger than that in the inner surface side surface layer portions and is set to 700 to 1600 MPa in the region from the surfaces to a depth of 0.03 mm.