MANUFACTURING METHOD OF A DRAWN CUP NEEDLE ROLLER BEARING HAVING SEAL RING

摘要

A method of manufacturing a drawn cup needle roller bearing having a seal ring, including forming the seal ring by a press working by: punching a metal plate to form an annular first intermediate material; subjecting the first intermediate material to burring working such that a portion close to an inner diameter of the first intermediate material is bent in an axial direction at a right angle to form an annular second intermediate material having an L-shaped cross section, the second intermediate material comprising a cylindrical portion and an outward flange portion which is bent radially outward from an axial end portion of the cylindrical portion; removing the outward flange portion to form a cylindrical third intermediate; and subjecting the third intermediate material to cold rolling working to regulate an inner diameter, an outer diameter and a cross sectional shape of the third intermediate material.