GB100134A - Improvements in the Manufacture of Blades for Steam and Gas Turbines. - Google Patents

Abstract

100,134. Akt.-Ges. Brown, Boveri, et Cie., and Christlein, P. March 1, 1915, [Convention date]. B l a d e s for axial-flow turbines are formed with non-parallel entrance and exit edges and their front and back surfaces as parts of cylindrical, conical, or like surfaces having any basic contour which can be produced simply by drawing, milling, pressing, turning, &c., the process consisting (1) in cutting from such cylindrical or like surface c, Fig. 4, a piece of constant axial width, or of axial width increasing from the blade root to the tip, in such a manner that the direction of the cut d-d, Fig. 3, is inclined to the generatrix e-e, or (2) in making the blade by coiling a strip a, Fig. 15, of the desired cross-section obliquely on a cylinder. The resulting entrance and exit edges f<1>-f<2>, g<1>-g<2> of the blades may be parts of mutually crossing helical or straight lines, and the cutting angles w<1>, w<2> on the entrance side and also the exit angles v<1>, v<2> may be constant or vary from tip to root. The thickness s of the blades may be constant, as shown, or the cross-section may increase from tip to root, the increase occurring either on the front face or on the back of the blade. The blade root may be suitably inclined to obtain radial edges and considerably thickened for strength.