Abstract: An air duct assembly for a gas turbine compressor rotor in a gas turbine engine is described. The rotor includes a compressor spool shaft and at least one stage disk, and the air duct assembly includes an elongate hollow cylindrical air duct configured to couple to a stage disk at a first end of the air duct. The second end of the air duct is configured to couple to the spool shaft. The second end of the air duct includes a plurality of lobes depending radially inward, a spool shaft insert configured to fit into an opening in the spool shaft, and a plurality of pins coupled to the spool shaft insert and configured to extend from the insert and to engage the lobes of the second end of the air duct.

Abstract: A seal assembly positioned between forward and aft rotor stages of a turbine separates a forward cavity and an aft cavity on each side thereof. The seal assembly includes a seal body connected to a platform portion of a stator nozzle located between the forward and aft rotor stages, wherein an inner seal cavity in flow communication with an insert in the stator nozzle is formed therebetween. A static seal member is arranged in sealing relationship with a rotary toothed member between the forward and aft cavities, with the static seal member being connected to the seal body. An intermediate member is positioned between the seal body and the static seal member to define a plenum therebetween in flow communication with the inner seal cavity, the intermediate member having a plurality of angled passages formed therein in which a first end thereof is in flow communication with the plenum and a second end thereof is in flow communication with the aft cavity.

Abstract: A generally wedge-shaped vibration damper for rotor blades of a gas turbine engine has a pair of scrubbing surfaces and is loosely retained in a pocket incorporated in the rotor blade platform. The pocket is partly defined by a plurality of surfaces which orient the damper so that it is slidably displaceable and rotatable only in a predetermined plane. During rotation of the rotor disk, the damper of one rotor blade is displaced in a plane transverse to the rotor axis of rotation by centrifugal forces to a position at which one scrubbing surface of the damper abuts a side surface of the platform of the adjacent rotor blade and the other scrubbing surface abuts an inner surface of the platform of the rotor blade in which the damper is inserted. The scrubbing action of the damper serves to damp vibratory motion in the platforms of both blades.

Abstract: A variable pitch propeller blade system includes a conductive clevis attached to a rotor, a mating non-conductive clevis fastened to a non-conductive propeller blade, a pin journaling through bores in each clevis, joining the clevises to form a hinge joint, and a conductive path along a substantial part of the propeller blade.

Abstract: A generally wedge-shaped vibration damper for rotor blades of a gas turbine engine has a pair of scrubbing surfaces and is loosely retained in a pocket incorporated in the rotor blade platform. The pocket is partly defined by a plurality of surfaces which orient the damper so that it is slidably displaceable and rotatable only in a predetermined plane. During rotation of the rotor disk, the damper of one rotor blade is displaced in a plane transverse to the rotor axis of rotation by centrifugal forces to a position at which one scrubbing surface of the damper abuts a side surface of the platform of the adjacent rotor blade and the other scrubbing surface abuts an inner surface of the platform of the rotor blade in which the damper is inserted. The scrubbing action of the damper serves to damp vibratory motion in the platforms of both blades.

Abstract: A vibration damper for rotor blades of a gas turbine engine has a shaft and a contact head connected thereto. The shaft is slidably inserted in a cylindrical recess incorporated in the rotor blade platform. During rotation of the rotor disk, the shaft of the damping member slides along the shaft axis, whereby the damping member is moved at least in the radial and circumferential directions by centrifugal forces. The contact head of the damping member of one rotor blade finally bears against the platform portion of an adjacent rotor blade, serving to damp vibratory motion of both blades.

Abstract: An aircraft propeller system of the unducted fan type includes a plurality of propeller blades which are respectively fastened to a rotor, rotate about an axis of rotation and also rotate about a pitch axis. Each blade is fastened to the rotor by a hinge which has a pivot axis to reduce the effective stiffness of each blade, the pivot axis being non-parallel to the axis of rotation.

Abstract: In an aircraft propeller which can change in pitch, each propeller blade is mounted upon a hinge, which reduces the effective stiffness of each blade. The angle of the hinge pin can be constructed such that the angle between torsional and flexural nodes is favorable.