Patent ID: 8567059
Filing Date: 2013-10-29
Classification: B23C,B24B,B24D,F01D,F05D,Y10T

Abstract:
1. A process for forming a firtree slot in a disc of a rotor of a gas turbine engine, the firtree slot being adapted to receive a root of a blade of the rotor therein and having first and second side walls having respective first and second finished side wall profiles, the process sequentially comprising the steps of: making a first pass with a machining quill to form a rough profile of the firtree slot; after making the first pass, making a second pass with an inclined first finishing guill having the shape of the first finished side wall profile of the firtree slot and avoiding engagement with the second side wall; after making the second pass, making a third pass with an inclined second finishing guill having the shape of the second finished side wall profile of the firtree slot and avoiding engagement with the first side wall, in order to provide a the firtree slot for receiving and fixing the root of the blade; and wherein at least one of the first, second and third passes includes passing the respective one of the machining quill, the first finishing quill and the second finishing quill along an axis that is substantially parallel to an axis of rotation of the disc.