Abstract: A fan blade includes a metal airfoil having first and second opposite sides extending radially between a root and a tip, and axially between a leading edge and a trailing edge. The airfoil further includes a pocket disposed in the first side having an elastomeric filler bonded therein. A panel is bonded to the filler along the pocket for allowing differential movement therebetween for damping vibratory response of the airfoil.

Abstract: A fan blade includes a metal airfoil having first and second opposite sides extending radially between a root and tip, and axially between a leading edge and a trailing edge. The airfoil further includes a plurality of pockets disposed in the first side and separated by corresponding ribs. A filler is bonded in the pocket, and is coextensive with the airfoil first side. Radial and diagonal ribs respectively intersect solely each other for selectively increasing torsional and bending stiffness to increase frequency margin between adjacent torsional and bending resonant modes of vibration.

Abstract: A fan blade includes a metal airfoil having first and second opposite sides extending radially between a root and tip, and axially between a leading edge and a trailing edge. The airfoil further includes a plurality of pockets disposed in the first side and separated by corresponding ribs. A filler is bonded in the pocket, and is coextensive with the airfoil first side. Radial and diagonal ribs respectively intersect solely each other for selectively increasing torsional and bending stiffness to increase frequency margin between adjacent torsional and bending resonant modes of vibration.

Abstract: A fan blade includes a metal airfoil having first and second opposite sides extending longitudinally between a root and a tip, and laterally between a leading edge and a trailing edge. The airfoil further includes a plurality of fine striations spaced laterally apart between the leading and trailing edges in the airfoil first side, and extending longitudinally between the root and the tip. A viscoelastic filler is bonded in the striations for damping torsional vibrations of the airfoil.

Abstract: The present invention provides a method and apparatus including a rotor mountable fixture for guiding a cutting tool powered by a hand held air motor to machine a gas turbine engine rotor without removing the rotor from its mountings in the engine. In one particular embodiment the fixture includes a root having the same contour as a blade root slot of a rotor, a base having a platform attached to the root, and a machining guide in the form of a bushing restrained in a guide slot operable to receive and guide a hand held air motor powered cutting tool for machining the rotor. The present invention provides an accurate means to machine a gas turbine engine rotor without removing the rotor from its mounting. In one particular embodiment a method for machining the rotor in the field is provided using a hand held air motor to power a machining tool to cut a blade damper pocket in the dovetail slot of a pressure compressor rotor.

Abstract: The present invention provides a phase independent damper and damper assembly capable of damping rotor blade vibrations in the axial, circumferential, and radial directions. One embodiment, particularly useful in an aircraft gas turbine engine compressor rotor, provides a damper and damper assembly including a generally axially extending blade damper operable to fictionally engage a generally axially extending circumferentially facing surface of a disk and axially extending angled surface under the platform of the blade. The invention provides an additional advantage of allowing simple and easy modification of existing engines to incorporate the damper of the present invention.

Abstract: A method of using a rotor mountable fixture for guiding a cutting tool powered by a hand held air motor to machine a gas turbine engine rotor without removing the rotor from its mountings in the engine is provided. In one particular embodiment the fixture includes a root having the same contour as a blade root slot of a rotor, a base having a platform attached to the root, and a machining guide in the form of a bushing restrained in a guide slot operable to receive a guide a hand held air motor powered cutting tool for machining the rotor. The present invention provides an accurate means to machine a gas turbine engine rotor without removing the rotor from its mounting. In one particular embodiment a method for machining the rotor in the field is provided using a hand held air motor to power a machining tool to cut a blade damper pocket in the dovetail slot of a pressure compressor rotor.