GB1336808A - Arrangement of bearings in a gas turbine jet engine - Google Patents

Abstract

1336808 Gas turbine engines - arrangements of bearings SOC NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION 3 March 1972 [3 March 1971] 10000/72 Heading FIG [Also in Division F2] The invention relates to a method of mounting a thrust bearing of a compressor and turbine assembly of a gas turbine engine whereby in the event of shaft failure, the turbine rotor and the thrust bearing may move axially rearwardly whereby the turbine rotor blades engage the stator blades so preventing excessive speed of the rotor. The invention is described with reference to a gas turbine ducted fan engine, the turbine rotor being indicated at 4, the compressor and turbine shaft at 3, and the thrust bearing assembly at 13. The inner race 15 is secured to the shaft 3 by screwed ring 16 and the outer race 20 is secured within a housing 21 by a screwed ring 20a, a member 22 against which the outer race 20 abuts being secured to the housing 21 by means 22a. The housing 21 is formed integrally with a thin disc portion 21c so that it is axially movable, the outer periphery of the disc portion being secured to fixed structure 14 at 23. In normal operation the axial thrust on the compressor and turbine assembly is forward so that a projection 21a of the housing 21 abuts against a projection 14c of the fixed structure 14. In the event of shaft failure the shaft 3 and turbine rotor 4 are permitted to move axially rearwardly by flexing of the thin disc 21c whereby the rotor blades contact the stator blades so preventing excessive rotational speed of the rotor; the housing 21 moves axially rearwardly so that the abutting portions 21a, 14c disengage. The member 21 is guided within the structure 14 at the points 14b, 14d.