摘要 |
A method and apparatus carrying the method for sealing a radial gap between coaxial inner and outer rotating shafts of a gas turbine engine includes using a radial seal as a main seal to seal the gap for a normal engine operation condition, and using an axial seal as a back-up seal for a double seal of the gap. The radial seal provides a seal which meets relatively restrictive leakage requirements for the normal engine operation condition and the axial seal 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. Thus, 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 are affected by unbalancing forces caused by the bird strike, thereby causing a failure of the radial seal. The inter-shaft axial and radial seal arrangement according to the present invention has a very simple structure which is convenient and economical to manufacture and maintain.
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