SEALING METHOD AND DEVICE FOR A GAS TURBINE SHAFT

摘要

A method and apparatus for sealing a radial gap (27) between coaxial inner and outer rotating shafts (26, 28) of a gas turbine engine includes using a radial seal (64) as a main seal to seal the gap (27) for a normal engine operation condition, and using an axial seal (70) as a back-up seal for a double seal of the gap. The radial seal (64) provides a seal which meets relatively restrictive leakage requirements for the normal engine operation condition and the axial seal (70) provides a back-up seal which meets less restrictive leakage requirements but is much more tolerant of radial displacement and vibration between the coaxial inner and outer rotating shafts. An engine operable condition is ensured under abnormal conditions, such as bird strikes, in which the coaxial relationship between the inner and outer rotating shafts (26, 28) are affected by unbalancing forces caused by the bird strike, thereby causing a failure of the radial seal.