GB610113A - Improvements in or relating to gas-turbine engines - Google Patents

Abstract

610,113. Jet propulsion plant. LOMBARD, A. A. March 25, 1946, No. 9203. [Class 110 (iii)] The invention relates to an internal-combustion gas turbine plant of the kind in which a compressor is driven by a coaxial axial flow turbine by a driving shaft extending between the turbine and compressor, the air from the compressor passing to a number of combustion chambers which are arranged in a ring around the driving shaft and deliver combustion products to an annular nozzle guide vane assembly and further in which there is provided an intermediate casing lying within the ring of combustion chambers between the compressor and turbine. The invention consists in the combination, in a turbine plant of the kind described, of a number of nozzle boxes adapted to convey combustion products from the combustion chambers to the nozzle guide vane assembly and a structure forming a chamber to accommodate the nozzle boxes, which structure includes a ring formed with apertures to support the outlet ends of the combustion chambers and is connected to the outer turbine structure and the intermediate casing to transmit structural loads therebetween. The turbine rotor 10, 11, Fig. 2, is supported from the compressor casing through a bearing 13 carried by a structure 14 extending from an intermediate casing 15 which is bolted to the compressor casing. The exhaust duct assembly 8, the turbine shroud ring 17 and the outer ring shroud 19 of the guide vane assembly are bolted together and attached by a conical ring 25 to an apertured ring 26 by which they are supported from the intermediate casing 15. The apertured ring 26 supports the ends of the combustion chambers 7 and the inlet ends of the nozzle boxes 33. The combustion chambers 7, Fig. 3, carry at their ends strengthening rings 7a which slide on the inner surfaces of a bush 31 inserted in the apertures of the ring 26. The nozzle boxes 33 are of fabricated sheet metal and are welded as at 34 to a ring 35. The ring 35 and bush 31 are attached to the apertured ring 26 by bolts 36. The exit ends of the nozzle boxes are supported between the casing 23 and the ring 37 disposed between the outer shroud ring 19 and the conical ring 25. Bolted to the inner diameter of the apertured ring 26 is a tubular member 23 which carries at its rearward end the inner guide vane shroud ring 20 and seal 20a. The guide vanes 21 have radial clearance in rings 19 and 20 so that loads on these rings are not imparted to the blades. A sheet metal collector ring 40 is bolted to the nozzle box casing by studs 27 and 24 to form a cooling air space to which cooling air is taken from the interior of the member 23 by pipes (not shown). According to the Provisional Specification the members 25, 26 are castings, but may be made of sheet metal with flanges welded on.