GB811586A - Turbine or compressor blades - Google Patents

Abstract

811,586. Making turbine and compressor blades. DE HAVILLAND ENGINE CO. Ltd. July 23, 1957 [July 25, 1956], No. 23060/56. Class 83 (2). [Also in Group XXVI] A method of making a turbine or compressor blade, Fig. 9, having one or more passages 10, 11 for a cooling or heating fluid comprises forming inner and outer hollow tubular elements 6, 1, assembling them together to provide at least one space 10 therebetween and then deforming them simultaneously by pressure applied to the wall of the outer element to lock the inner element firmly in position. The outer element 1 is made by forging; its walls may be of varying or constant thickness and its bore may be conical or cylindrical. The inner element 6 may be made by forging or may be cut from a piece of tube and one end closed; the outer surface thereof may have longitudinal grooves 8, Fig. 5, and its wall thickness may vary both along its length and also to provide opposite thin portions 16; alternatively the wall thickness may be constant, Fig. 4 (not shown). The inner element may have a constant or tapering outer diameter. After insertion within the outer element, the inner element is located by a clamp or jig and both elements are then pressed in a series of steps to aerofoil shape with the thin portion 16 of the inner element being located adjacent the leading and trailing edges of the blade. The grooves 8 may be filled during pressing with a cement which is subsequently removed to leave passages 11. The two elements may be secured together by brazing. Finally the root is machined to fir-tree shape, Fig. 7, a fluid inlet passage 13 is drilled through the root and passages 14 are formed in the trailing edge communicating with the passage 10. Other passages may be formed in the outer wall to communicate with the passages 11.