GB603798A - Improvements in and relating to high temperature elastic fluid turbines - Google Patents

Abstract

603,798. Gas turbines. BRITISH THOMSON-HOUSTON CO., Ltd. (General Electric Co.). Oct. 30, 1945, No. 28728. [Class 110 (iii)] To supply cooling air to hollow blades which are mounted on a solid turbine disc and have radial channels extending through their tips, a rotatable plate is attached to the inlet side of the disc to form with it a cooling space to which the radial channels are connected and means are provided to circulate cooling air through the space and channels. The exhaust gas turbine shown, Fig. 1, has two plates 12, 16 welded to the disc 1 to form cooling spaces 26, 27 and has hollow blades 2 through which the cooling air passes to the duct 41 on its way to the atmosphere. Cooling air is supplied to the spaces 26, 27 from a duct 10 formed between the bearing 4 and the annular plate 9. The clearance space between the nozzles 7 and blades 2 is sealed from the duct 10 by a plate 30 welded at its outer edge to the nozzle inner support ring and provided with a two-tie. labyrinth packing at its inner edge which prevents leakage along the turbine shaft 3 and the inner edge of plate 16. Two radially spaced shrouds 20, 21 provided at the tips of the blades form a passageway 22 which is'used to convey working fluid leaking outwardly from the clearance space between the nozzles and. blades back into the exhaust gas stream. The part of this leakage which does not pass through the passageway 22 is cooled by mixing with the cooling air from the blades in the duct 41 before passing to atmosphere. The passageway 22 may be provided with blades to pump the gases through it. The cooling spaces 26, 27 are connected by ducts 28 in the disc 1 and the turbine is controlled by regulating the amount of gas passing through a bye-pass 8. The blades 2 are welded to the disc 1. The cooling air supply to the duct 10 may be supplied from a vane diffuser on the front of the aircraft facing the slipstream.