Abstract: A bearing assembly for use in a gas turbine engine to rotatably mount a torque tube in an access hole extending through a fan duct. The torque tube connects a variable stator vane bell crank positioned inside the fan duct to an actuator positioned outside the fan duct. The bearing assembly includes a bearing having a spherical external engagement surface and a housing having a flange and an annular interior surface having an inner edge and an outer edge. The interior surface is sized and shaped for rotatably receiving the spherical external engagement surface of the bearing so the spherical engagement surface and the annular interior surface make contact along an annular contact area centered on a contact plane lying between the inner and outer edges. The contact plane is tilted with respect to the flange at an angle greater than five degrees.

Abstract: A bearing assembly for use in a gas turbine engine to rotatably mount a torque tube in an access hole extending through a fan duct. The torque tube connects a variable stator vane bell crank positioned inside the fan duct to an actuator positioned outside the fan duct. The bearing assembly includes a bearing having a spherical external engagement surface and a housing having a flange and an annular interior surface having an inner edge and an outer edge. The interior surface is sized and shaped for rotatably receiving the spherical external engagement surface of the bearing so the spherical engagement surface and the annular interior surface make contact along an annular contact area centered on a contact plane lying between the inner and outer edges. The contact plane is tilted with respect to the flange at an angle greater than five degrees.

Abstract: A pitch feathering system for a gas turbine driven aircraft propeller having multiple variable pitch blades utilizes a counter-weight linked to the blades. The weight is constrained to move, when effecting a pitch change, only in a radial plane and about an axis which rotates about the propeller axis. The system includes a linkage allowing the weight to move through a larger angle than the associated pitch change of the blade.

Abstract: In a compressor section of a gas turbine engine, a double wall casing is provided wherein a nonstructural inner wall is removably attached to a thin, structural outer casing. The inner wall isolates the thin stator outer casing during transient turbine operations of throttle burst and throttle chop. During throttle burst and chop, the nonstructural inner wall delays rapid heating and cooling of the relatively thin-walled outer casing, and reduces radial misalignment between the stator casing and rotor due to uneven thermal expansion and contraction. The nonstructural inner wall evens-out thermal expansion and contraction of the stator casing with respect to the rotor. To fine tune the actual clearances between stator and rotor and prevent the casing outer wall from overheating, thermal insulation material is used between the nonstructural inner wall and outer casing.