GB781478A - Improvements in or relating to rotors for axial flow compressors and turbines - Google Patents

Abstract

781,478. Turbine and compressor rotors. BRISTOL AERO-ENGINES, Ltd. July 20, 1955 [Aug. 9, 1954], No. 23142/54. Class 110 (3). In a rotor such as is used in axial flow compressors and turbines and which comprises a number of blade-carrying discs, a stub shaft projecting from an end of the rotor is connected to at least one blade-carrying disc and is further connected to a spigot-like part which projects axially into the rotor structure and which is connected at its end remote from the stub-shaft to another blade-carrying disc at a radial distance from the axis of the rotor which is at the most not substantially greater than the radial distance at which the spigot-like part is connected to the stub shaft. In the compressor rotor of a gas turbine engine shown in Figs. 1a, 1b, a stub shaft 13 has a radial flange 20 which is secured by bolts 16 to blade-carrying discs 11, 12 which have axial flanges 11b, 12b forming spacing members projecting towards each other. The stub shaft is mounted in a bearing 14. A spigot-like part 39 having inward and outward flanges 41, 40 is secured at one end by the bolts 16 to the stub shaft 13 and at the other end by bolts 44 to the third blade-carrying disc 21. The pitch circle of the bolts 44 is of smaller diameter than that of the bolts 16. The rotor also comprises four more blade-carrying discs 22, 23, 24, 25, the discs having abutting flanges 12a and 21a, 21b and 22a, 22b and 23a, 23b and 24a and the discs are connected together by long bolts 29 passed through axially-aligned holes in the abutting flanges. The compressor rotor is drivingly connected to the turbine rotor by means of a shaft 60 which is connected at its end 36 to the compressor by means of the bolts 29. The spigot-like member 39 which is in the form of a tubular member having radial flanges at its ends communicates with a further tubular member 47 which is closed at its end remote from the member 39 and connects by means of radial tubes 52 with the working fluid annulus of the compressor. Air under pressure may flow through the tubes 52 to the spaces within the members 39, 47 and issue through ports 55 in the flange 20 of the stub shaft 13 to be used as sealing and cooling air. In a further embodiment a frusto-conical ring has a radial flange at its upstream and smaller diameter end and an axial flange at its downstream and larger diameter end. The radial flange is interposed between the disc 12 and the radial flange 40 of the spigot-like part 39 and is secured by the bolts 16, while the axial flange is disposed in the same position as the flange 21a of Fig. 1a and is provided with axial holes through which the long bolts 29 extend.