GB848562A - Improvements relating to the construction of gas turbine engines - Google Patents

Abstract

848,562. Making turbine rotors. GARRING- TONS Ltd. May 15, 1957 [May 17, 1956], No. 15352/56. Class 83 (2). [Also in Group XXVI] Gas turbine engine components such as turbine rotor discs or compressor impeller discs comprise a rotor of substantially frusto-conical form and a plurality of flat or substantially flat vanes which extend radially in angularly spaced relationship therefrom, the rotor being formed by a forging operation and each vane also being formed by a separate forging opeiation. The rotor is formed subsequent to the forging operation, with a series of angularly spaced blind holes extending axially inwardly from the larger diameter face thereof and with radially extending slots communicating with the holes and each vane is formed at its inner end with an enlarged root portion which is subsequently engaged in a keyhole shaped slot in the rotor so as to secure the vane against radial and angular displacement. The invention is shown applied in the case of a bladed impeller disc 10 of a radial flow compressor of a gas turbine engine, the impeller disc forging shown at the left-hand side of Fig. 2 being subsequently machined to provide a series of blind holes 18 extending axially from the face 19 of larger diameter, and a series of radially disposed slots 20 extending through the periphery of the disc and communicating with the holes 18. The vanes 11 are formed as flat forgings having an enlarged root portion 12 of circular cross-section extending from the side 13 of the vane to just past the centre line thereof. The vanes are entered into the slots in the impeller disc from the left-hand side, Fig. 3, and are secured to the impeller disc by means of screws 22.