Abstract: A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing.

Abstract: A bearing housing for connecting a bearing to a supporting structure of a gas turbine engine is discussed. The bearing housing has an inner wall and an outer wall radially spaced apart from the inner wall between which an annular space is defined. A device extends from the inner wall toward the outer wall and includes at least a first and a second member in series between the inner and outer walls, the second member having a radial stiffness greater than a radial stiffness of the first member. The device may operate in multiple operating stages, where in a first stage the first member of the device deforms to absorb at least partially a vibration load over a given range of vibration amplitude when the bearing housing deflects, and where in a subsequent second stage the second member of the device increases a total radial stiffness of the assembly of the bearing housing and device over the bearing housing alone.

Abstract: A bearing housing for connecting a bearing to a supporting structure of a gas turbine engine is discussed. The bearing housing has an inner wall and an outer wall radially spaced apart from the inner wall between which an annular space is defined. A device extends from the inner wall toward the outer wall and includes at least a first and a second member in series between the inner and outer walls, the second member having a radial stiffness greater than a radial stiffness of the first member. The device may operate in multiple operating stages, where in a first stage the first member of the device deforms to absorb at least partially a vibration load over a given range of vibration amplitude when the bearing housing deflects, and where in a subsequent second stage the second member of the device increases a total radial stiffness of the assembly of the bearing housing and device over the bearing housing alone.

Abstract: A steel soft wall fan case assembly according to one embodiment configured with a thin-walled steel support structure shell including a plurality of annular axial walls of thin sheet metal reinforced by a plurality of rings interconnecting axially adjacent annular axial walls. The steel support structure shell is structurally integrated with honeycomb materials and an annular metallic inner wall. A fabric containment layer may be wrapped around one of the annular axial walls of the steel support structure shell.

Abstract: A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing.

Abstract: A frangible mounting arrangement between a bearing and a bearing support in a gas turbine engine comprises a plurality of frangible bolts connecting mounting flanges of the bearing and the bearing support. The bolts are disposed on a circle. A distance on the circle between a first pair of adjacent bolts is greater than a distance on the circle between a second pair of adjacent bolts. The bolts are configured to break when subjected to a breaking load above a predetermined value. The breaking load results from at least one of a bending moment and a shear load on the mounting flanges. When subjected to the breaking load, the first pair of adjacent bolts breaks before the second pair of adjacent bolts. A method of providing a frangible mounting arrangement between a bearing and a bearing support is also provided.

Abstract: A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing.

Abstract: A steel soft wall fan case assembly according to one embodiment configured with a thin-walled steel support structure shell including a plurality of annular axial walls of thin sheet metal reinforced by a plurality of rings interconnecting axially adjacent annular axial walls. The steel support structure shell is structurally integrated with honeycomb materials and an annular metallic inner wall. A fabric containment layer may be wrapped around one of the annular axial walls of the steel support structure shell.

Abstract: A steel soft wall fan case assembly according to one embodiment configured with a thin-walled steel support structure shell including a plurality of annular axial walls of thin sheet metal reinforced by a plurality of rings interconnecting axially adjacent annular axial walls. The steel support structure shell is structurally integrated with honeycomb materials and an annular metallic inner wall. A fabric containment layer may be wrapped around one of the annular axial walls of the steel support structure shell.

Abstract: A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing.

Abstract: A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing.

Abstract: A steel soft wall fan case assembly according to one embodiment configured with a thin-walled steel support structure shell including a plurality of annular axial walls of thin sheet metal reinforced by a plurality of rings interconnecting axially adjacent annular axial walls. The steel support structure shell is structurally integrated with honeycomb materials and an annular metallic inner wall. A fabric containment layer may be wrapped around one of the annular axial walls of the steel support structure shell.

Abstract: A frangible mounting arrangement between a bearing and a bearing support in a gas turbine engine comprises a plurality of frangible bolts connecting mounting flanges of the bearing and the bearing support. The plurality of frangible bolts is disposed on a circle. A distance on the circle between a first pair of adjacent frangible bolts is greater than a distance on the circle between a second pair of adjacent frangible bolts. The frangible bolts are resistant to axial loads and being configured to break when subjected to a breaking load above a predetermined value. The breaking load results from at least one of a bending moment and a shear load on the mounting flanges. When subjected to the breaking load, the first pair of adjacent frangible bolts breaking before the second pair of adjacent frangible bolts. A method of providing a frangible mounting arrangement between a bearing and a bearing support in a gas turbine engine is also provided.

Abstract: A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing.

Abstract: A turbofan engine comprising an annular inner wall surrounding tips of the fan blades, a layer of insulating material surrounding the inner wall, and an outer casing including an annular outer wall surrounding the insulating material and concentric to the inner wall and at least two annular rub elements extending radially inwardly from the outer wall through only part of a radial thickness of the layer of insulating material, at least two of the rub elements being in axial alignment with the blade tips at every point around a circumference of the fan, each rub element having a radially inner end spaced apart from the inner wall and made of a material harder than that of the blades, and a containment fabric layer wrapped around a support structure of the outer wall.

Abstract: The method is used for making an annular gas turbine engine case from a preform. The method comprises comprising flowforming at least one section of the preform, and then outwardly bending at least one portion of the perform.

Abstract: A gas turbine engine rotor containment structure comprises an inner structurally supporting case having an inner surface positioned adjacent to a gas turbine engine rotor component to be contained. A layer of acoustic material is wrapped around and bounded to a radially outer surface of the inner case. A thin walled outer ring is bounded to a radially outer surface the layer of acoustic material. A layer of fibrous containment material surrounds a radially outer surface of the outer ring.

Abstract: A turbofan engine comprising an annular inner wall surrounding tips of the fan blades, a layer of insulating material surrounding the inner wall, and an outer casing including an annular outer wall surrounding the insulating material and concentric to the inner wall and at least two annular rub elements extending radially inwardly from the outer wall through only part of a radial thickness of the layer of insulating material, at least two of the rub elements being in axial alignment with the blade tips at every point around a circumference of the fan, each rub element having a radially inner end spaced apart from the inner wall and made of a material harder than that of the blades, and a containment fabric layer wrapped around a support structure of the outer wall.

Abstract: A gas turbine engine rotor containment structure comprises an inner structurally supporting case having an inner surface positioned adjacent to a gas turbine engine rotor component to be contained. A layer of acoustic material is wrapped around and bounded to a radially outer surface of the inner case. A thin walled outer ring is bounded to a radially outer surface the layer of acoustic material. A layer of fibrous containment material surrounds a radially outer surface of the outer ring.

Abstract: The method is used for making an annular gas turbine engine case from a preform. The method comprises comprising flowforming at least one section of the preform, and then outwardly bending at least one portion of the perform.