GB617472A - Improvements in or relating to gas-turbine-engines - Google Patents

Abstract

617,472. Gas turbine blades and rotors. LOMBARD, A. A., MORLEY, F. W. W., DAVIS C. A., and WILKINSON, S. C. Oct. 2, 1946, Nos. 29426 and 29427. [Class 110 (iii)] Gas turbine blades, or segments carrying blades, are made with shouldered shanks 20, Fig. 1, gripped between two turbine discs 10, 11 which are secured together by bolts or rivets 22 located radially outside the engaging shoulders 18. The discs are also secured together by a central sleeve 14 and nut 16. In Fig. 1, blades 23 have fir-tree roots secured in segments 28 formed with the shouldered shanks 20. In Fig. 3, each blade 52 has a shouldered shank 57. In Fig. 5, each blade 52 has a shank with shoulders 54, which lie radially inside the disc-fastening rivets 56, and additional shoulders 72. The turbine discs 10, 11, Fig. 1, have interfitting internal flanges 13, internal shoulders 34 defining an annular recess in which an aluminium ring 35 fits and abutting flanges 32. Cooling air passes through holes 17, slots 36 cut in the ring 35, holes 33 and slots 27, 25 cut in the shoulders of the shank 20 and the thickened portions of the turbine discs. The air passes out through slots 30 which open into the blade sockets and through slots 31 cut in the blade-carrying segments between the blade sockets. The' blades may be hollow and cooling air be passed through them. The turbine discs 40, 41, Fig. 3, have central flanges 44 which are bolted together and covered by a ring 47. The flanges and the ring have air passages 46, 48. The discs have two pairs of internal flanges 60, 66 against which aluminium rings 61, 67 fit and the rings have a number of slots 62, 68 to provide passages for cooling air. Adjacent sides of the blade roots are grooved to form clearance slots through which contacting lands 55 on the discs project. These lands determine the spacing of the discs and the blades may be fitted with a slight axial clearance. The grooves in the sides of the blade roots open into the rotor interior to admit cooling air to the slots. Cooling air is also guided over the exterior of the discs.