Method for manufacturing a rotor for a generator, especially a turbogenerator

At its outer circumference, a gap (37) widens out into a cavity (38) bordering the weld seam (17). The cavity is designed to occupy the smallest possible volume, whilst minimizing local mechanical stressing. The weld seam has a circumferential root at the inner edge. At the radial location of the weld root, on each side of it, there is an undercut profile. Between the undercut and the gap (37) there is a transition contour. This is linear and flows into the gap at a given angle. It is alternatively arcuate with given radius. Axially-running winding grooves are distributed over the circumference of the rotor (10). They are radially-orientated, with a depth (Tn). At the weld seams (17), the groove depth (Tn) is less than the weld seam depth (Tw). The rotor components (11-14) are cylindrical. The weld seam (17) depth (Tw) is constant over the entire circumference of the rotor. The connecting surfaces are planar and at right angles to the rotor axis (18). The rotor is made up from main cylindrical sections of a first outer diameter, and two shaft ends with second and third outer diameters. The first diameter exceeds each of the second and third diameters. The welds are only used within the region of the main cylindrical sections. The rotor includes the two shaft ends and many discs (12, 13) welded together. Axial lengths of these discs vary. Shaft ends (11, 14) and/or discs include one or more central cavities. These are penetrating- or blind bores. For material inspection and/or for supply and return of coolant, radial channels pass from the cavities to the outer contour of the rotor, or to winding grooves in the rotor cylinder. The gap width is approximately equal to the weld seam width. To make the rotor, it is welded as described, annealed and skimmed by turning. Winding grooves are then milled into it. Small annular projections extend axially from the original rotor components, assist centering, alignment and definition of gap sizes. An independent claim IS INCLUDED FOR the method of manufacture. Ein Rotor (10) für einen Generator, insbesondere einen Turbogenerator, ist aus mehreren, in der Rotorachse (18) hintereinander angeordneten, separaten Rotorelementen (11, 12) zusammengesetzt, wobei die Rotorelemente (11, 12) an Anschlussflächen aneinander stossen und unter Ausbildung von kreisringförmigen Schweissnähten (17) miteinander verschweisst sind, welche jeweils einen kreisförmigen zentralen Spalt (37) mit einer vorgegebenen Spaltbreite konzentrisch umsch