Method for manufacturing ball bearings having a sintered metal powder outer race

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 curvilinear portion joining the inner and outer arcuate faces; the side face on the preform having a concentric generally wedge-shaped annular flange thicker at its bottom than at its top and having a wall distal to the inner annular face, preferably formed as part of a generally V-shaped groove in the side face, which wall is straight from top to bottom and extends at an oblique angle of preferably approximately 45.degree. to the normal to the side face; positioning an inner race within the opening defined by the outer race; positioning a plurality of balls intermediate the inner and outer races; and deforming at least a portion of the flange radially inwardly to generate an entrapment for the said balls between the inner annular face of the preform and the inner race; such deformation preferably being achieved by advancing a generally annular deforming tool having an annular working wall, 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.