GB412868A - An improved process of making bearing raceways - Google Patents

Abstract

412,868. Making bearings. SKERRETT, H. N., 24, Temple Row, Birmingham.- (Timken Roller Bearing Co.; Denber Avenue, Canton, Ohio, U.S.A.) Jan. 9, 1934, No. 866. [Classes 83 (ii) and 83 (iv).] Working at specified temperatures.-Conical raceway members for roller bearings are formed by die-forging a " semi-hot " cylindrical metal ring or an annular slug into a ring having one portion of its surface of conical form and of substantially the taper and diameter required for the raceway. The annular slug from which the race members are formed is obtained from a seamless tube by cutting off a section therefrom and broaching out its centre portion to ensure its inner and outer surfaces being concentric. In forming an inner race member A, Fig. 9, a slug with an external diameter equal to that of the rib 9 at the narrower end of the cone is placed in a die 5<a>, Fig. 8, having a flared upper end 10<a> and when the slug is upset by the punch 6a, a recess 11 in a shoulder piece 7<a> on the punch forms a rib 8 at the wider end of the cone 10. A cylindrical portion 9<a> at the narrower end of the ring is cut away to continue the taper and undercut the rib 9, the rib 8 being undercut also. In forming an outer race member, the die 5<a> corresponds to the diameter of the slug and the finished member and a conical punch forms the conical inner surface. The forging operations are carried out at a temperature below that at which scale would form, 1000 to 1400‹ F. being suitable for the nickel molybdenum steel alloy from which such raceways are usually formed.