Patent ID: 8925201
Filing Date: 2015-01-06
Classification: B23P,F01D,F05D,Y10T

Abstract:
1. A method of making blade fixing slots in a disc of a bladed rotor for use in a gas turbine engine, the method comprising: determining a plurality of circumferential locations on the disc for receiving the blade fixing slots, the blade fixing slots being adapted to receive roots of respective airfoil blades of the bladed rotor; determining a virtual full slot profile of each of said blade fixing slots, the virtual full slot profile being adapted to correspond to a profile of the roots of the airfoil blades; using wire electro-discharge machining (EDM) to form a single-cut pre-slot in the periphery of the disc at each of said plurality of circumferential locations, the single-cut pre-slots being planar slits which extend radially inwardly from an outer periphery of the disc, each planar slit having a uniform width corresponding to a diameter of a single EDM cutting wire from the wire EDM and thus a shape which does not correspond to a shape of the full slot profile of the blade fixing slot to be made, the single-cut pre-slots reducing residual stress in the disc prior to forming said blade fixing slots; and forming the blade fixing slots having said full slot profile in the periphery of the disc at each of said circumferential locations, using the single-cut pre-slots as pilot guides by circumferentially aligning a center of the full slot profiles with the single-cut pre-slots.