GB1279119A - Apparatus and method for circumferentially-directed welding - Google Patents

Abstract

1279119 Welding by fusion LANG GEPGYAR 18 Sept 1969 46141/69 Heading B3R In apparatus for welding a ring seam on a product having a cylindrical surface, or welding a root seam on a steam turbine rotor, a structure 4 is joined about the axis of the product and rotatably supports a structure 3 on which is mounted at least one welding device 10, 11. In Fig. 1 the structure 3 rotates on bearing balls 6 which run in grooves in the two structures. The structure 4 is adjustably mounted on a part 1 by stems 5 acting through rubber pads 9. In Fig. 2 (not shown), structure 4 has feet (22) connected through a heat insulating medium 17 to members 16 which are affixed to the part 1; and a heat shield (19) protects machine operators. Fig. 3 shows apparatus for welding a root seam on a steam turbine rotor 15. The rotor sits on centring blocks 39 and is attached via bolts 38 and rubber washers 37 to a frame 35 which is secured in a ring 32 pivotally mounted by shafts 46 in bearing blocks 33 having babbit metal linings. Structure 3 carries columns 42 on which are mounted seats 43 for the location of electrodes 44. In operation the rotor is heated by electrical resistance heating units (not shown) and then welded. After welding the structures 3 and 4 are removed and the apparatus is pivoted so that the rotor is in a horizontal position, Fig. 4 (not shown). Drive of structure 3 can be by gearing 12, 13, Fig. 1, by a worm or belt drive or as shown in Fig. 5 where the structure 3 is rotated by the application of a tangential magnetic force to soft iron ring 61. A flexibly mounted electromagnet 68 is energized to engage ring 61 against the action of spring 70. An electromagnet 65 is then energized to move a core 64 against the action of spring 71. This latter movement causes structure 3 to rotate.