Auxiliary power unit exhaust duct bellmouth incorporating revolute joints to facilitate installation and removal of said auxiliary power unit

摘要

A hinging bellmouth for an exhaust duct of an auxiliary power unit (APU) comprises a fixed nozzle portion, a motive nozzle portion of substantially the same geometry, a revolute joint interface comprising at least two hinge barrels with their necessary support structure and hinge pin, and a fastener interface. The revolute joint interface allows the motive nozzle portion to remain in contact with the fixed nozzle portion during APU installation and removal. The fastener interface allows the hinging bellmouth to be maintained in a closed position during APU operation.