GB580036A - Improvements in or relating to rotors for turbo-machines - Google Patents

Abstract

580,036. Turbine blades and rotors. STRUB, R. Feb. 23, 1945, No. 4583. Convention date, Feb. 25, 1944. [Class 110 (iii)] [Also in Group XXII] In a method of manufacture of turbine rotors the blades are welded together to form a rim and then welded to a rotor disc. Finally the discs are welded to each other and end pieces to form the complete rotor. The blades 2, Fig. 2, are fitted together to form a rim held against movement by the rings 3 of a holder and secured by bolts 4. The inner edge of each blade root 1 is tapered so that the interspaces 5, formed by assembly of the blades, form a groove for a weld seam 6. After welding the blade rim is internally machined ; the broken shading in Fig. 3 being the part removed forming a flat 7 and adjoining taper surfaces 8. These surfaces co-operate with surfaces 9, 11, Fig. 4, when the blades are mounted on a rotor disc to provide a weld seam 12. The double shaded portion is then removed by machining. In a modification the blades are welded on inter-spaces formed on the outside of the blade roots, which are then gripped on the inside by the holder to allow access for welding tools. Alternatively, welds may be made in inter-spaces formed on both the inside and outside of the rim formed by the blade roots. Further a pin may be fitted to the bottom of a weld to extend substantially across the width of the blade root ; in the case of double welds this pin is fitted between the weld seams. In another form a square pin 24, Fig. 11, fitted between the welds, has slots 25 to engage an easily deformed wire 26. The weld contracts on cooling, deforming the wire, and allows the pin to fit tight against the sides 27 of the groove in the blade roots. Alternatively the blade rim can be welded to a rotor disc which is drilled in the middle and keyed to a shaft; a solid rotor body, or a drum-shaped rotor body.