FAN CASE WITH FLEXIBLE CONICAL RING

摘要

The invention is a hardwall fan case for encasing a forward fan in a gas turbine engine. The fan case has a stiff annular shell spaced radially outwa rd from the tips of the fan blades and a flexible ring which is an integral structural part of the shell. The flexible ring has a frusto-conical shape with a lip adjacent to the blade trailing edge. The ring extends axially rearwardly from the fixed root to the free inner edge forming a cantileverin g resilient ring. A hollow cavity defined between an inner surface of the shel l and an outer surface of the flexible ring provides clearance for the flexibl e ring to deform radially outwardly on impact with a released blade, or to elastically flex on contact with the trailing edge blade tip during bird strike events.