In a conventional gas turbine engine, tubes are provided for channeling fluid such as fuel and air between components in the engine. Air tubes, for example, may be used for channeling compressor bleed air to selected engine components for providing cooling air.
A gas turbine engine operates at relatively high temperatures wherein both hot combustion gases and cool cooling air are channeled. Accordingly, differential temperatures are found in the gas turbine engine which result in differential thermal movement of adjacent turbine components. Furthermore, the engine includes rotating shafts and blades which generate vibratory forces on the engine components.
Accordingly, couplings used for joining fluid conduits to engine components are subject to differential thermal movement between adjacent components and vibratory forces in axial and transverse directions. Furthermore, where conduits are to join stationary adjacent components, the coupling should allow for installation and removal of the conduits without moving the stationary adjacent components.
Conventional couplings effective for accommodating differential thermal movement and vibratory forces while still maintaining acceptable seals for containing fluid flow are relatively complex, heavy, and expensive. For example, a metallic flexible bellows is known for providing a leak proof seal while accommodating axial and transverse movements. However, bellows are relatively complex and require considerable design and testing to ensure adequate durability and life in service in a gas turbine engine.