Pratt-Whitney Canada Corp

Czeslaw Wojtyczka

David Denis

Oleg Korshikov

Philippe Bonniere

Milica Kojovic

Lena Raykowski

Andreas Eleftheriou

Richard Ivakitch

Andrew Marshall

Barry Barnett

Stephen Caulfeild

Steven Hunt

Samy Amin

Camil Rabinovici

Stanislaw Kuzniar

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. The bumper further has an axially forwardly facing surface which is axially spaced by a predetermined axial fore gap from a first flange projecting radially outwardly from a front end portion of the outer race of the bearing. The first flange of the outer race is axially trapped between the stator structure and the bumper. After decoupling, the bearing is free to axially and radially move within the radial gap and the axial fore gap.

Post FBO windmilling bumper

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.

Bearing housing with damping arrangement

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.

Steel soft wall fan case

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.

Frangible mounting arrangement and method for providing same

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.

Fan case with rub elements

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.

Annular gas turbine engine case and method of manufacturing

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.

Fan case for turbofan engine

A fan blade fragment containment assembly for a gas turbine engine having a fan case surrounding the fan and having a circumferential axially extending blade fragment impact zone. An inner relatively slack or low tension deformable layer of Kevlar&trade; or Zylon&trade; fabric is mounted to the fan case outer surface and envelopes the impact zone. A compressible (ex. metal foam or honeycomb) layer is mounted on an outer surface of the deformable layer. A friction reduction layer of Teflon&trade; is mounted on an outer surface of the compressible layer and an outer relatively taut higher tension containment layer of Kevlar&trade; or Zylon&trade; fabric is mounted on an outer surface of the friction reduction layer. The friction reduction layer enhances the distribution of impact forces about the circumference of the compressible layer by reducing local shear stresses between the compressible layer and the containment layer.

Fan case design with metal foam between Kevlar

There is provided a hardwall fan case for encasing a forward fan in a gas turbine engine. The fan case has a stiff annular shell spaced radially outward from the tips of the fan blades and a flexible ring which is an integral structural part of the shell. The flexible ring has a frusto-conical shape with a lip adjacent to the blade trailing edge. The ring extends axially rearwardly from the fixed root to the free inner edge forming a cantilevering resilient ring. A hollow cavity defined between an inner surface of the shell and an outer surface of the flexible ring provides clearance for the flexible ring to deform radially outwardly on impact with a released blade, or to elastically flex on contact with the trailing edge blade tip during bird strike events.

Fan case with flexible conical ring

The invention provides a novel hardwall fan case for encasing the radial periphery of a forward fan in a gas turbine engine. The fan case includes a rigid annular fan case shell spaced a selected radial distance from the tips of the fan blades, thus defining an annular internal air path surface of the fan case. The shell has a rigid hardwall fore section generally parallel to the blade tips and coated with a fore layer of abradable material. The fore section serves as a hardwall to limit the radial movement of fan blades deflecting under bird strike conditions and thereby to control the erosion of fan case linings. Limiting the radial blade deflection thus maintains the resulting fan tip clearance within acceptable limits. Uncontrolled or excessive erosion of fan case linings during bird strike conditions has in the past led to potentially catastrophic engine surge conditions where highly aerodynamically loaded fans are used that are very sensitive to enlarged tip clearances. The aft section of the rigid shell is radially spaced from the fore section thus defining a recess between the aft section of the rigid shell and the air path surface. The recess houses compressible material that absorbs the impact of the broken blade fragment propelled radially, and can retain the fragment in certain conditions. However, the rigid shell includes a novel rigid bumper between the fore and aft sections. The bumper has a rigid rear edge disposed an offset distance forwardly of the fan blade centers of gravity. When a broken blade fragment is propelled radially under centrifugal force, the fragment strikes the bumper edge. The blade fragment is rotated about the bumper edge under a force moment equal to the centrifugal force multiplied by the offset distance. As a result, the blade fragment is redirected from a radial trajectory and is rotated rearwardly to be ejected axially through the gaspath, or alternatively is retained within the compressible material housed in the rigid shell. Both the rigid hardwall fore section and the aft compressible material are preferably covered with a relatively thin layer of abradable material that allows the rotating fan blades on initial operation to achieve close tip tolerance with the hardwall fan case.

Growing community of inventors

Brampton, Canada

Czeslaw Wojtyczka