Abstract: During operation, a bladed rotor disk typically experiences out-of-plane vibration which can result in deterioration and/or cracking at the interface between adjacent shrouds of the turbine blades. In an embodiment, slots are formed at the end of a labyrinth seal segment of each shroud. Preloaded spring strips are inserted through the slots to couple adjacent shrouds while preventing the natural frequency of the turbine blades from drifting to the operating speed range and/or providing vibration damping to the untuned blade mode.

Abstract: A damped turbine blade assembly for a gas turbine engine is disclosed. The damped turbine blade assembly includes a damper positioned within a first small slot of a first turbine blade and a second large slot of the second turbine blade. A portion of the damper can slidably mate with the second large slot providing a radial and angular connection between the first turbine blade and second turbine blade while allowing movement in a direction tangent to a radial of a center axis of the gas turbine engine. The tangential movement is resisted by friction between the damper contacting the second large slot and provides friction damping against vibrations felt by the turbine blades during operation of the gas turbine engine. The damper can be shaped and/or pre-stressed to control the normal force component of the friction between the damper and the second large slot.

Abstract: A damped turbine blade assembly for a gas turbine engine is disclosed. The damped turbine blade assembly includes a damper positioned within a first small slot of a first turbine blade and a second large slot of the second turbine blade. A portion of the damper can slidably mate with the second large slot providing a radial and angular connection between the first turbine blade and second turbine blade while allowing movement in a direction tangent to a radial of a center axis of the gas turbine engine. The tangential movement is resisted by friction between the damper contacting the second large slot and provides friction damping against vibrations felt by the turbine blades during operation of the gas turbine engine. The damper can be shaped and/or pre-stressed to control the normal force component of the friction between the damper and the second large slot.

Abstract: The present disclosure relates generally a gas turbine engine and a rotor therefor. The rotor may include a symmetric rim thereon to prevent the propagation of induced vibratory responses. The rim may have one or more sloping surfaces to prevent the re-attachment of boundary layer flow.

Abstract: A bumper bearing assembly includes a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines a bearing seat. A bumper bearing is connected to the bearing housing by a spring having a level of radial spring stiffness lower than that of the bearing housing. The bumper bearing is configured to apply the level of radial spring stiffness of the spring against a rotor with the bumper bearing spaced apart from the bearing seat. The bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the bumper bearing seated against the bearing seat.

Abstract: A rotor blade comprises a blade platform and an airfoil. The airfoil comprises a blade tip, a leading edge, and a trailing edge with a stiffening compound lean contour. The blade tip is radially opposite the blade platform, and defines a blade span between the blade itself and the blade platform. The leading and trailing edges extend from the blade platform to the blade tip to define blade chords between the leading edge and the trailing edge. The compound lean contour comprises a positive lean section located at the lean tip, and extending along a lean axis to a lean end. The negative lean section is located radially inward of the positive lean section, and extends along the lean axis to the lean end.

Abstract: The present disclosure is applicable to all gear trains using a journal bearing as a means of supporting gear shaft rotation. It is related in some embodiments to a system and method for supplying lubricant to the journal bearings of a gear-turbofan engine gear train when the fan rotor is subjected to a wind-milling condition in both directions, either clockwise or counter-clockwise.

Abstract: A turbine wheel is disposed about an axis and has a back face including a plurality of lobes disposed about a periphery of the back face. The lobes define scalloped areas therebetween. The scalloped areas are further defined by a radius BR2 that blends into a first lobe and into a radius BR1 that also blends into a flat area.

Abstract: A reduction in excitation amplitudes affecting turbine blade durability in a turbine nozzle assembly having a plurality of vanes and turbine blades, includes: identifying a turbine blade design of the turbine nozzle assembly; performing a modal model analysis of at least one of the turbine blades in the turbine blade design; reducing aerodynamic impact by ensuring that each of the turbine blades is free of aero-excitation from an upstream flow at the vanes in an operating speed range; identifying blade natural frequencies with respect to the nozzle vanes; and modifying a trailing edge of at least one of the vanes to reduce the excitation amplitudes.

Abstract: A brush seal land is disclosed. The brush seal land may comprise a first portion configured to be coupled to a turbine disc of an aircraft engine and a second portion having a contact surface. The brush seal land may comprise a concave annular structure. The second portion may deflect through a clearance area in response to contact with a brush. The second portion may not deflect in response to contact with a brush after the second portion has deflected through a clearance area in response to contact with the brush. The contact surface comprises tungsten carbide. The brush seal land may comprise INCONEL. The brush seal land may be configured to be coupled to an annular member extending from the turbine disc. The brush seal land may reduce abrasion to an annular member extending from the turbine disc by a brush.

Abstract: A bearing support assembly includes a squirrel cage defining a longitudinal axis and having a cylindrical portion defining a bearing seat. The squirrel cage is configured and adapted to provide a first level of radial support stiffness between a housing and a bearing seated in the bearing seat. A damper sleeve is operatively coupled to the cylindrical portion of the squirrel cage through a fluid film to dampen relative radial motion between the damper sleeve and the squirrel cage. A radial spring component is operatively connected to a side of the damper sleeve radially opposite the cylindrical portion of the squirrel cage to provide a second level of radial support stiffness.

Abstract: A bumper bearing assembly includes a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines a bearing seat. A bumper bearing is connected to the bearing housing by a spring having a level of radial spring stiffness lower than that of the bearing housing. The bumper bearing is configured to apply the level of radial spring stiffness of the spring against a rotor with the bumper bearing spaced apart from the bearing seat. The bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the bumper bearing seated against the bearing seat.

Abstract: A rotor blade comprises a blade platform and an airfoil. The airfoil comprises a blade tip, a leading edge, and a trailing edge with a stiffening compound lean contour. The blade tip is radially opposite the blade platform, and defines a blade span between the blade itself and the blade platform. The leading and trailing edges extend from the blade platform to the blade tip to define blade chords between the leading edge and the trailing edge. The compound lean contour comprises a positive lean section located at the lean tip, and extending along a lean axis to a lean end. The negative lean section is located radially inward of the positive lean section, and extends along the lean axis to the lean end.

Abstract: A gas turbine engine is provided comprising an impeller configured to rotate about an axis. A combustor is in fluid communication with the impeller. An inflow radial turbine is aft of the impeller and in fluid communication with the combustor. The inflow radial turbine includes a rotor with a bore having a flat bore end configured to rotate about the axis. A radial turbine is also provided comprising a rotor configured to rotate about an axis and a bore defined by a proximal portion of the rotor. The bore may have a flat bore end. A rotor is further provided comprising a disk configured to rotate about an axis and a bore partially through the disk along the axis. The bore may comprise a flat section extending radially from the axis and a curved section aft of the flat section.

Abstract: A brush seal land is disclosed. The brush seal land may comprise a first portion configured to be coupled to a turbine disc of an aircraft engine and a second portion having a contact surface. The brush seal land may comprise a concave annular structure. The second portion may deflect through a clearance area in response to contact with a brush. The second portion may not deflect in response to contact with a brush after the second portion has deflected through a clearance area in response to contact with the brush. The contact surface comprises tungsten carbide. The brush seal land may comprise INCONEL. The brush seal land may be configured to be coupled to an annular member extending from the turbine disc. The brush seal land may reduce abrasion to an annular member extending from the turbine disc by a brush.

Abstract: A bearing support assembly includes a squirrel cage defining a longitudinal axis and having a cylindrical portion defining a bearing seat. The squirrel cage is configured and adapted to provide a first level of radial support stiffness between a housing and a bearing seated in the bearing seat. A damper sleeve is operatively coupled to the cylindrical portion of the squirrel cage through a fluid film to dampen relative radial motion between the damper sleeve and the squirrel cage. A radial spring component is operatively connected to a side of the damper sleeve radially opposite the cylindrical portion of the squirrel cage to provide a second level of radial support stiffness.

Abstract: The present disclosure is applicable to all gear trains using a journal bearing as a means of supporting gear shaft rotation. It is related in some embodiments to a system and method for supplying lubricant to the journal bearings of a gear-turbofan engine gear train when the fan rotor is subjected to a wind-milling condition in both directions, either clockwise or counter-clockwise.

Abstract: The present disclosure relates generally a gas turbine engine and a rotor therefor. The rotor may include a symmetric rim thereon to prevent the propagation of induced vibratory responses. The rim may have one or more sloping surfaces to prevent the re-attachment of boundary layer flow.

Abstract: A diaphragm assembly includes a cylinder, a circular flange, and a diaphragm. The cylinder defines an axis and includes a first end and a second end opposite the first end. The circular flange is coaxial with the cylinder and at a greater radial distance from the axis than the cylinder. The diaphragm extends from the second end of the cylinder to the flange.

Abstract: A planetary carrier includes a journal bearing for supporting a planetary gear. The journal bearing receives lubricant to produce a lubricant film to support gear loads. A torque frame is attached to the carrier housing to transmit torque and to prevent twisting of the carrier housing. The torque frame includes several lubricant communication passages to provide lubricant to each of the separate journal bearings. Each of the lubricant communication passages includes an accumulator for storing lubricant during normal operation. The accumulator stores a desired amount of lubricant to provide lubricant to the adjacent journal bearing for the interim period between primary system stoppage and reestablishment of lubricant flow by a secondary system.