FANS AND TURBINES

摘要

Overlapping twisted radial aerofoil blades or vanes are formed on a compressor rotor or turbine disk or the like (102) by electro-discharge machining with a curved tool electrode which is in the form of an elongate and substantially rigid element other than a wire (150) which is turned by a tool holder (130) as it is advanced on a helical path to form the inner surface of each blade or vane with the outer curve of the electrode, or the outer surface of each blade or vane with the inner curve of the electrode, the disk being indexed to a next rotary position after each blade surface is machined.