Patent ID: 8966767
Filing Date: 2015-03-03
Classification: B21D,B21K,F16C,Y10T

Abstract:
1. A method of manufacturing a drawn cup needle roller bearing having a seal ring, the drawn cup needle roller bearing comprising: a shell having a raceway surface on a circumferential face and also having flange portions in both end portions; a cage having a plurality of pockets in a circumferential direction; a plurality of needles retained in the pockets so that the needles freely rotate along the raceway surface; and a cylindrical seal ring arranged between an end face of the cage and the flange portion of the shell, wherein the seal ring composes a floating seal and a height of a cross section of the needle roller bearing is 1.0 to 3.5 mm, the method comprising forming the seal ring by a press working, the press working comprising: 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, thereby obtaining the seal ring having a required shape accuracy and dimensional accuracy.