GB852826A - Improvements in the manufacture of hollow blades for fluid flow machines - Google Patents

Abstract

852,826. Making turbine and like blades; bonding; stamping; soldering. STALKER, E. A. Feb. 18, 1957, No. 5427/57. Classes 83 (2) and 83 (4). A hollow turbine or like blade comprising. upper and lower sheet metal parts 80, 96, Fig. 15, secured together along leading and trailing edges 98, 99, is made by joining the parts each with an integral nose-piece 95, 97, bringing the nose-pieces into registry and holding them so as to define the desired blade section rearwardly of the nose-pieces, securing the parts together by a metal fusion process such as soldering or brazing, at or adjacent the nose-pieces and then removing the nosepieces. In one embodiment the two parts are pressed from separate sheets; each part is then placed in a die 90, Fig. 14, where the leading end portion 93 is bent and reduced in thickness by a moving die 94 to form the nosepiece. The two parts are then tack welded together at 98, 99, solder wires 100, 101 are inserted at the junctions, the assembled parts are inserted in a rack 54 and passed through a furnace which forms a soldered joint. The leading and trailing edges are then trimmed to shape. In another embodiment the two parts 12, 14, Fig. 6, are formed from a single sheet with a common integral junction-piece 24, Fig. 3 (not shown), whichis drawn between dies 30, 32 to form a recess with side wall 16c, 16d. The junction may be reduced in thickness 28, Fig. 4 (not shown), before drawing. The side walls 16c, 16d are later squeezed together between dies 40, 41, Fig. 7 (not shown), to provide a junction which may be tack welded; the two parts are also tack-welded together at their trailing edge. The assembly is then soldered or brazed as in the first embodiment and the edges are subsequently trimmed and finished.