GB826087A - Rigid assembly, particularly for gas turbine engines, capable of accommodating inaccuracies of alignment in one direction - Google Patents

Abstract

826,087. Turbine nozzle assemblies. Mc- GREGOR, J. C. Nov. 6, 1957 [Nov. 14, 1956], No. 34620/57. Class 110 (3). [Also in Group XXV] The invention relates to a means of securing a gas turbine inlet nozzle guide vane assembly between inner and outer stationary parts of the engine structure. The nozzle guide vane assembly comprises a plurality, say twelve, bladed segments such as 4a each having an inner platform 12 and an outer platform 13. The inner stator structure comprises an inner annular wall 5 of the combustion equipment and an inner annular wall 7 of the flame tube, also annular members 8, 8<1>, 9 and 10. The outer stator structure comprises an outer annular wall 1a of the combustion equipment, an outer casing 1b around the turbine assembly, an outer annular wall 6 of the flame tube, an annular support ring 11 secured by means of a flange between the wall 1a and casing 1b, and an annular flange 6a. A channel-section member 10a is secured on the annular member 10, a series of axially-disposed pins 16 extending through the flanges of the channel member, the projecting ends 16a of the pins being shaped as shown in Fig. 2a and providing shoulders 16b. The inner platform 12 of each guide vane segment is provided with a pair of inwardly directed flanges 12a which are spaced so as to lie on either side of the flanges of the channel member 10a, the flanges 12a being notched at 12b so as to pass over the end portions 16a of the pins 16, the shoulders 16b abutting against the inner surfaces of the flanges 12a to prevent axial disengagement of the pins. The outer platform 13 of each guide vane segment is provided with a flange 13a which co-operates with a shroud ring (not shown), a reinforcing rib 13b, a flange 13c having an axially-extending flange 13e at its extremity and an upstream-projecting lip 13d which co-operates with the annular flange 6a of the flame tube wall 6. The axially-extending flange 13e engages between the limbs 11a, 11b of a channel-section formation provided at the inner end of the support ring 11. A number of equi-spaced radial holes 18 are provided in the flange 13e of each segment platform 13, and aligned pairs of equi-spaced radial holes 19, 20 are provided in the limbs 11a, 11b of the channel formation, the spacing of the holes 18 being slightly different from that of the holes 19, 20 so that one of the holes 18 in each platform flange 13e will be in alignment with a pair of holes 19, 20 in the limbs 11a, 11b in the manner of a vernier coupling. A pin 21 is passed through the aligned holes 18, 19, 20 whereby the platform 13 is located circumferentially, the pin having a shoulder 21a which bears on the outer surface of the limb 11a. A resilient annular member 1c secured on the inner surface of the casing 1b engages, upon assembly, with the ends of the pins 21 to prevent their disengagement radially.