Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A method of balancing a gas turbine engine rotor, including axisymmetrically removing an annular portion of the balancing flange exceeding that required to provide the unbalance correction, and creating the unbalance correction by non-axisymmetrically removing material from the balancing flange. In one embodiment, the configuration of a theoretical notch in the balancing flange that would create the unbalance correction is determined. The unbalance correction is created by removing material from the balancing flange to create a protuberance protruding radially from a remainder of the balancing flange, the protuberance having a height corresponding to the depth of the theoretical notch, a circumferential width corresponding to the arc angle of the theoretical notch, and a circumferential position diametrically opposed to the circumferential position of the theoretical notch. A gas turbine engine rotor is also discussed.

Abstract: A method of balancing a gas turbine engine rotor comprises the step of obtaining a rotor disc with a circumferential array of balance tabs projecting from a peripheral rim of the disc. Stress shielding scallops are defined in the rotor disc between the tabs. The balancing is achieved by removing material from at least one of the tabs.

Abstract: A method of balancing a gas turbine engine rotor comprises the step of obtaining a rotor disc with a circumferential array of balance tabs projecting from a peripheral rim of the disc. Stress shielding scallops are defined in the rotor disc between the tabs. The balancing is achieved by removing material from at least one of the tabs.

Abstract: A method of balancing a gas turbine engine rotor, including axisymmetrically removing an annular portion of the balancing flange exceeding that required to provide the unbalance correction, and creating the unbalance correction by non-axisymmetrically removing material from the balancing flange. In one embodiment, the configuration of a theoretical notch in the balancing flange that would create the unbalance correction is determined. The unbalance correction is created by removing material from the balancing flange to create a protuberance protruding radially from a remainder of the balancing flange, the protuberance having a height corresponding to the depth of the theoretical notch, a circumferential width corresponding to the arc angle of the theoretical notch, and a circumferential position diametrically opposed to the circumferential position of the theoretical notch. A gas turbine engine rotor is also discussed.

Abstract: A removable fan blade of a turbofan engine includes a blade root at one end thereof. A rotor disk has a retention slot having dimensions corresponding for receiving the root of the fan blade in the slot. An elongated resilient member extends within the retention slot in a lengthwise direction between the root of the fan blade and the bottom of the retention slot and an elongated member extends lengthwise between the root of the fan blade and the elastomeric member to compress the resilient member and provide a radial preload to the fan blade.

Abstract: A method of balancing a gas turbine engine rotor comprises the step of obtaining a rotor disc with a circumferential array of balance tabs projecting from a peripheral rim of the disc. Stress shielding scallops are defined in the rotor disc between the tabs. The balancing is achieved by removing material from at least one of the tabs.

Abstract: A gas turbine airfoil blade comprises an airfoil having a leading edge and a trailing edge defining fore and aft points of an airfoil chord relative to a flowpath direction. The airfoil extends generally radially from a root to a tip, the root of the airfoil intersecting a platform of the blade. A body of the airfoil is composed of a plurality of airfoil sections stacked along a stacking line extending radially from the platform. A root airfoil section being the one of said airfoil sections intersecting the platform, the trailing edge at the root airfoil section extending to intersect the platform chordwise aft of the trailing edge of the airfoil section immediately radially outwardly adjacent to the root airfoil section.

Abstract: A removable fan blade of a turbofan engine includes a blade root at one end thereof. A rotor disk has a retention slot having dimensions corresponding for receiving the root of the fan blade in the slot. An elongated resilient member extends within the retention slot in a lengthwise direction between the root of the fan blade and the bottom of the retention slot and an elongated member extends lengthwise between the root of the fan blade and the elastomeric member to compress the resilient member and provide a radial preload to the fan blade.

Abstract: A removable fan blade of a turbofan engine includes a blade root at one end thereof. A rotor disk has a retention slot having dimensions corresponding for receiving the root of the fan blade in the slot. An elongated resilient member extends within the retention slot in a lengthwise direction between the root of the fan blade and the bottom of the retention slot and an elongated member extends lengthwise between the root of the fan blade and the elastomeric member to compress the resilient member and provide a radial preload to the fan blade.

Abstract: The fan blade includes a blade root at one end thereof configured for sliding insertion into a substantially axially extending slot defined in a periphery of a fan rotor hub. The blade comprises a first passageway extending at least partially through the blade root, in a direction generally parallel to an axial direction of the slot. It also comprises a second passageway extending at least partially through the blade root to intersect with the first passageway. A first member is provided in the first passageway, the first member configured to be retained in the first passageway once inserted therein, and a second member is provided in the second passageway, the second member having one end in cooperating engagement with the end of the first member. The second member has a portion projecting out of the bottom face of the blade root a distance sufficient to contact an inner surface of the slot and thereby force the blade outwardly in the slot.

Abstract: An airfoil root fillet having a predetermined compound curve profile can be flank milled with a single flank milling cutter having a generally conical flank milling portion and a rounded tip portion defining a compound curve.

Abstract: An internal heating arrangement for a centrifugal impeller for a gas turbine engine is provided having at least one heating passage extending through into the rotor for directing air bled from the rotor exit along the backface and forwardly through the impeller.

Abstract: A device for controlling valve travel of the flush valve of a toilet operated by a rigid linkage rod and for forcibly returning the valve to the closed position. The device may comprise a spring contained within a sleeve. The sleeve has end caps bearing openings for passing the rigid linkage rod entirely through the sleeve and spring. One end cap may be threaded to enable it to compress and immobilize the spring for selectively defeating operation.

Abstract: A removable fan blade of a turbofan engine includes a blade root at one end thereof. A rotor disk has a retention slot having dimensions corresponding for receiving the root of the fan blade in the slot. An elongated resilient member extends within the retention slot in a lengthwise direction between the root of the fan blade and the bottom of the retention slot and an elongated member extends lengthwise between the root of the fan blade and the elastomeric member to compress the resilient member and provide a radial preload to the fan blade.

Abstract: The fan blade includes a blade root at one end thereof configured for sliding insertion into a substantially axially extending slot defined in a periphery of a fan rotor hub. The blade comprises a first passageway extending at least partially through the blade root, in a direction generally parallel to an axial direction of the slot. It also comprises a second passageway extending at least partially through the blade root to intersect with the first passageway. A first member is provided in the first passageway, the first member configured to be retained in the first passageway once inserted therein, and a second member is provided in the second passageway, the second member having one end in cooperating engagement with the end of the first member. The second member has a portion projecting out of the bottom face of the blade root a distance sufficient to contact an inner surface of the slot and thereby force the blade outwardly in the slot.

Abstract: An airfoil root fillet having a predetermined compound curve profile can be flank milled with a single flank milling cutter having a generally conical flank milling portion and a rounded tip portion defining a compound curve.

Abstract: An internal heating arrangement for a centrifugal impeller for a gas turbine engine is provided having at least one heating passage extending through into the rotor for directing air bled from the rotor exit along the backface and forwardly through the impeller.

Abstract: A tuning notch is defined preferably in the back of a blade root to tune the blade natural frequency in a gas turbine engine.

Abstract: A cold forging apparatus for forming complex shapes at a single station includes a plurality of multiple function punch assemblies disposed on intersecting axes. Each of the multiple function punch assemblies includes an inner or a center punch and an outer or ring-shaped punch surrounding and in sliding contact with the inner punch. The apparatus also includes a die holder for positioning a mass or slug of metal between the punches. A computer system controls movement of the punches and is programmable to form parts of different shapes at a single station. Off axis punches and angularly offset punches and an additional punch or punch assembly are also disclosed.