Patent GB-755919-A (GB)
Title: Improvements in compressor or turbine blades
IPC: F01D5/18
Filed: 1953-06-08
Abstract: 755,919. Turbine and compressor blades. GENERAL MOTORS CORPORATION. June 8, 1953 [June 9, 1952; June 9, 1952; June 9, 1952], No. 15679/53. Class 110(3) [Also in Group XXII] , A blade for a compressor or turbine, for example a gas turbine blade, comprises laminal interleaved and secured together as a pack so that by their formation and method of interleaving, passages for coolent flow are defined between certain laminal. In Figs. 1, 3 and 4 the blade comprises a series of laminations 16 which extend from root to tip of the blade and are spaced by pairs of laminations 17, 18 which are formed with openings 19, 22 respectively to provide sinuous passages for the flow of cooling air. The laminations 41 adjacent the end laminations 16 are open along their length except at their tips and the adjacent laminations 42 are formed with openings 43. The shorter laminations 46, 47 are similarly formed, and the laminations 48, 49 are both open except at their tips. The root portion of the blade is completed by root blocks 13, 14 and the leading and trailing edges of the blade by V- shaped sheet-metal pieces 32, 33, the edges of the laminations 16, 17, 18 forming the concave 'and convex surfaces of the blade between the pieces 32, 33. The root blocks and the edges of all the laminations are grooved to form a fir-tree type of root. Cooling air passes through the passage 31 in the rotor disc C into the spaces 26 and 30 in the blade root and then through the passages between the laminations. In Fig. 5, the laminations 51 extend the full length of the blade and are spaced apart by means of short laminations 52 at the root portion, each of the laminations 52 being formed in two parts to define a cooling air passage therebetween. Laminations 41, 42, 46, 47, 48, 49 are provided as in the first embodiment. All the laminations are enclosed within a sheath 50. In Fig. 9, the laminations 126 extend the full length of the blade and are spaced apart by short laminations 123 at the blade root, the laminations 123 being furmed in two parts 123a, 123b (see Fig. 16), spaced apart to define air inlet passages. Short laminations 127, 128 are disposed towards the leading and trailing edges of the blade. The blade is completed by root blocks 117, 118 and by a sheath 121 enveloping all the laminations. In a further embodiment, Fig. 16, additional narrow laminations 136 are disposed centrally between the laminations 126, 127, 128 and reduce the cross-sectional area of the coolant passages. In Figs. 17, 18, 19 the laminations 146, 147, 146<SP>1</SP>, 147<SP>1</SP> all extend into the blade sheath 121 and are staggered, the laminations 146, 146<SP>1</SP> engaging the convex surface of the sheath and the laminations 147, 147<SP>1</SP> engaging the concave surface of the sheath. A short lamination such as 146a is associated with each lamination 146, 147 at the root portion. In Figs. 21, 24 the blade comprises series of laminations 216 which extend across the full thickness of the blade and intermediate laminations which are made in two parts 217a, 217b so as to define ducts 218 for cooling air. The blade is completed by root blocks 219, 221 and leading and trailing edge pieces 227, 228. In..Fig. 26, the leading and trailing edge pieces 237, 238 are solid, strips of metal being cast or forged from a highly heat-resistant alloy. In Fig. 27, the blade is of entirely laminated construction, the central portion of the blade being similar to the construction shown in Fig. 21. Laminations such as 252 are bifurcated towards the tip to provide a central passage, while laminations 253 are closed at the tip and bifurcated nearer the base. The laminations 245 are divided along their entire length similarly to the laminations 217a, 217b of Fig. 24.