GB1338347A - Turbo-machines - Google Patents

Abstract

1338347 Gas turbine: jet propulsion engines SOC NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION 1 June 1972 [2 June 1971] 25670/72 Headings F1J, F1G and FIT A two-tier blade assembly comprises , Fig. 1, radially inner and outer compressor and turbine blades 3, 4, respectively, separated by a hollow box 5, defined by walls 9, 10, 11, the circumferentially adjacent boxes forming an annular passage 8, which receives cooling air from the compressor through gaps 12 between adjacent walls 9. The cooling air thence flows through drillings 14 in walls 10 and into passages 13 in turbine blades 4 before escaping through tip openings 15. The boxes 5, 5a of axially adjacent blade rings interfit at 16 to reduce leakage. The machine may be of contra-rotating type or may have fixed stators. Each box 5 and its associated blades 3, 4, may be made as a single casting, as two parts welded together at (17), Fig.4 (not shown)), or incorporating a dovetail root fixing (18), Fig.5 (not shown). The blade assembly may form part of a gas turbine jet propulsion by-pass engine, Fig.8, in which the rotor discs 20, 20a respectively have further sets of compressor blades 19, 19a inwardly of blades 3, 3a. The blades 19, 19a may be in the same plane as discs 20, 20a or offset therefrom, as shown, and supply air via centrifugal compressor 22 to blades 3, 3a. The latter feed a reverse flow combustion chamber 28 which directs gases to drive blades 4, 4a and further turbine blades 23.