GB934514A - Improvements in or relating to methods of forming annular blanks - Google Patents

Abstract

934,514. Forging; punching; making roller bearing races. SVENSKA KULLAGERFABRIKEN A.B. Dec. 19, 1961 [Dec. 20, 1960; Dec. 21, 1960], No. 45402/61. Classes 83 (2) and 83 (4). An annular blank is formed by piercing a heated substantially cylindrical solid workpiece 21a from opposite ends successively, using substantially fully conical tools 24, 210. The workpiece 21a is formed by upsetting a solid cylindrical workpiece, Fig. 4 (not shown); simultaneously a locating spigot 25 is provided. During the first piercing step by punch 24, Fig. 6, the spigot seats in a recess 26 in a bed 29. The workpiece is then reversed, the conical recess located over a spring-loaded finger 27, Fig. 7, and punch 210 then pierces from the opposite end and punches out a small wad 212, Fig. 8. The spigot 25 is also pressed out. For making the inner and outer races of roller bearings, Fig. 9, an inner blank 2 which subsequently forms the inner race, is punched out of an outer workpiece 3 which forms the outer race. Simultaneously the blank 2 is pierced from one end by punch nose 5; it is then reversed and pierced from the opposite end, Fig. 11 (not shown), and then again reversed and further pierced from the first end, Fig. 12 (not shown). Finally the blank is rolled in a ring rolling mill. The punches may be wholly conical or have a rounded nose or a short cylindrical or reverselyconed nose, Figs. 13-15 (not shown). They are made of hard metal with sufficient porosity to permit lubricant from an interior reservoir to seep to the outside.