Method for manufacturing ball bearings; a sintered metal outer race preform for use therein; and a ball bearing produced thereby

Abstract

A method for manufacturing ball bearings and a sintered metal outer race preform for use therein in which the method comprises the steps of forming a generally annular sintered metal outer race preform, the preform preferably having a composition of a 97-99.4% iron and 0.60 to 1.00% carbon; the preform being fabricated from sintered metal powder and having a sinter density of approximately 6.1 to 6.5 grams per cubic centimeter and a sintered hardness of Rb 20 to 40; the preform having arcuate, concentrically disposed inner and outer annular faces, the inner face having a radially inwardly disposed curvilinear portion on one side thereof, and an annular side face on the side of the preform opposite the said curvilinear portion joining the inner and outer arcuate faces; the said side face having a concentric generally wedge-shaped annular flange thicker at its bottom than at its top and having a wall distal to the said annular face, preferably formed as part of a generally V-shaped groove in the said side face, the said wall distal to the said inner annular face being straight from top to bottom and extending at an oblique angle of preferably approximately 45.degree. to the normal to the said side face; positioning an inner face within the annulus defined by the outer race; positioning a plurality of balls intermediate the inner and outer races; and deforming at least a portion of the said flange radially inwardly to generate an entrapment for the said balls between the said inner face of the preform and the inner race; the said deformation preferably being achieved by advancing a generally annular deforming tool having an annular face, straight from its top to its bottom, disposed at an angle of approximately 5.degree. from the plane of said side face of the preform, perpendicularly thereto to engage the top of said flange until it is deformed radially inwardly sufficiently to entrap the balls to the extent desired.

Dependencies are inferred from the claim text.