Abstract: A vacuum pump has an end portion and a flange extending from a periphery of the end portion. The flange portion has first and second opposed main surfaces, and first and second bolt insertion holes extending through the first and second main surfaces. An auxiliary ring is connected to the first main surface of the flange portion of the pump case. The auxiliary ring has first and second opposed main surfaces, and a third bolt insertion hole extending through the first and second main surfaces of the auxiliary ring. An auxiliary ring attaching bolt extends through the third bolt insertion hole for connecting the auxiliary ring to a chamber housing disposed opposite the end portion of the pump case. A pump case supporting bolt extends through the second bolt insertion hole of the pump case flange portion and is connected to the auxiliary ring, and a pump case fastening bolt extends through the first bolt insertion hole of the pump case flange portion and is connected to the auxiliary ring.

Abstract: An energy absorber and deflection device for deflecting engine debris fragments from their tangential trajectory from a core of a gas turbine engine. The device includes a deflection plate radially spaced from a protected portion of the periphery of the rotor, adapted to cover the protected portion in a closed position, and to swing open about a fore edge of the deflection plate to a deployed position. A flexible joint secures the fore edge of the deflection plate to the engine and a frangible joint secures an aft edge of the deflection plate to the engine. In the case of a turbofan engine, the deflector plate may form part of the inner bypass duct surface to deflect debris to exit aft through the bypass duct, and in turboshaft and turboprop engines the deflector plate serves to deflect debris and reduce debris velocity to contain debris within the engine cowling or nacelle.

Abstract: An energy absorber and deflection device for deflecting engine debris fragments from their tangential trajectory from a core of a gas turbine engine. The device includes a deflection plate radially spaced from a protected portion of the periphery of the rotor, adapted to cover the protected portion in a closed position, and to swing open about a fore edge of the deflection plate to a deployed position. A flexible joint secures the fore edge of the deflection plate to the engine and a frangible joint secures an aft edge of the deflection plate to the engine. In the case of a turbofan engine, the deflector plate may form part of the inner bypass duct surface to deflect debris to exit aft through the bypass duct, and in turboshaft and turboprop engines the deflector plate serves to deflect debris and reduce debris velocity to contain debris within the engine cowling or nacelle.

Abstract: A tip treatment bar (16) for use in a gas turbine engine casing is provided with a cavity which is open on one side of the bar (16), the cavity being filled with a damping material (24). The bars (16) may be open ended. The damping material (24) reduces vibration amplitudes in the bar (16) caused by aerodynamic excitation, thus reducing high cycle fatigue of the tip treatment bars (16).

Abstract: 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™ or Zylon™ 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™ is mounted on an outer surface of the compressible layer and an outer relatively taut higher tension containment layer of Kevlar™ or Zylon™ 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.

Abstract: The invention relates to a gas turbine seal, comprising a metallic component (1) with a durable or erosion-resistant ceramic coating (2) and an abradable ceramic layer (18) which is arranged thereon in locally delimited fashion, a bond layer (5) being arranged on the surface (4) of the metallic component (1), to which bond layer the durable or erosion-resistant ceramic coating (2) is applied as a covering layer. The invention is characterized in that the bond layer (5) comprises separate, adjacent spherical rivets (6) or mushroom-shaped rivets (6) which have a web (7) and a head (8). These rivets form individual metal islands with numerous undercuts (12), around which there is a continuous ceramic network. It is possible to produce very thick layers which have a good bond strength, the ceramic not being flaked away even in the event of introduction of radial/tangential forces, sickle-shaped contact or locally high overheating/frictional heat, and a good sealing action being achieved.

Abstract: A locking device (36) for use in retaining an assembly of rotor blades against movement around a rotor disc on which they are mounted comprises a body member having first and second portions interconnected by a weakened region (66) whereby a force applied to turn the first portion (38) relative to the second portion (40) can cause them to shear apart at said weakened region (66) thereby facilitating release of seized devices to enable blade removal.

Abstract: A fan containment case assembly 30 of a gas turbine engine 10 includes a hardened fan case liner 42 disposed therein. In the event of a fan blade loss condition, the hardened fan case liner allows for circumferential movement of the fan blade tips 38 around the fan case 48. Thus, the liner reduces the destructive cutting away of the fan case, minimizing damage to the fan case and decreasing torque loading of the fan case from rotor deflections. Alternate embodiments of the fan case liner are described.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) has an upstream portion (56), a transition portion (58) and a blade containment portion (54). The upstream portion (56) has a flange (42) connecting the metal casing (40) to a flange (48) on axially adjacent casing (46). The blade containment portion (54) has a greater thickness (T2) than the thickness (T1) of the upstream portion (54). The transition portion (58) connects the blade containment portion (54) and the upstream portion (56) to transmit loads from the blade containment portion (54) to the flange (42) on the upstream portion (56). The ratio of the thickness (T4) of the flange (42) on the upstream portion (56) to the thickness (T1) of the upstream portion (56) is between 3 to 1 and 6 to 1.

Abstract: A compressor casing with a volute-shaped flow duct is fastened by means of a rigid fixing arrangement to the bearing casing of the turbomachine, with simple and low-cost means in such a way that the emergence of fragments of a burst compressor impeller from the compressor casing can be prevented. The compressor casing has an outer spiral casing, which surrounds a duct section of the flow duct deflected towards the outside into the radial direction (B), and an inner casing insert piece, which is provided in the radial direction (B) between the spiral casing and the compressor impeller and whose inner contour, together with the outer contour of the hub of the compressor impeller, forms the duct section of the flow duct extending essentially in the axial direction (A).

Abstract: The broken shaft detection system and method uses a detector assembly mounted downstream of a power turbine wheel of a gas turbine engine to detect rearward axial motion of the wheel and thereby a broken shaft event. The detector assembly has a plunger positioned to be axially displaced against a link connected in an electrical circuit. The link may be broken when the plunger is displaced thereby creating an open circuit that may be detected by a detection and test element. The breaking may be communicated to an overspeed circuit that controls a shut off switch that interrupts fuel flow to the engine. The link may be connected to the detection and test element by two pairs of parallels wires to facilitate monitoring of circuit function and to detect failures that are not broken shaft event failures.

Abstract: A gas turbine engine 10 includes an intermediate pressure compressor 14 connected to an intermediate pressure turbine 22 by a driveshaft 28. The driveshaft 28 comprises a downstream turbine shaft 34 attached to the intermediate pressure turbine 22 and an upstream compressor shaft 32 attached to the intermediate pressure compressor 14. The compressor shaft 32 and turbine shaft 34 are connected together by a splined connection 36 which allows the turbine shaft 34 to drive the compressor shaft 32. If the splined connected 36 should fail, so that it no longer transmits torque, a further splined connection 41 comes into operation to transmit torque between the turbine shaft 34 and compressor shaft 32. When this happens, torque is transmitted via a torsionally weakened, shear section 48 of the turbine shaft 34 which tends to break under certain engine conditions. The turbine shaft 34 is then released axially and turbine overspeed is restrained.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) which has an inner surface (62), an outer surface (64), an upstream flange (42) and a downstream flange (52). The outer surface (62) of the metal casing (40) is provided with a pattern of blind apertures (66) which extend radially inwardly from the outer surface (62) of the metal casing (40) between the flanges (42,52). The fan blade containment has reduced weight of the metal casing (40) of the fan blade containment assembly (38) for a large diameter turbofan gas turbine engine (10) but has unimpaired stiffness and penetration resistance.

Abstract: A turbo-molecular pump includes a casing having an intake port, a stator fixedly mounted in the casing, and a rotor supported in the casing for rotation relatively to the stator. The stator and the rotor make up a turbine blade pumping section and a groove pumping section for evacuating gas. A scattering prevention member is provided for preventing fragments of the rotor from being scattered through the intake port.

Abstract: A turbofan gas turbine engine (10) comprises a fan rotor (32) carrying a plurality of radially extending fan blades (34). A fan blade containment assembly (38) surrounds the fan blades (34) and the fan blade containment assembly (34) comprises a generally annular, or frustoconical, cross-section casing (52). At least one corrugated sheet metal ring surrounds the casing (52) wherein the corrugations extend with axial and/or circumferential components.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) which has an inner surface (62), an outer surface (64), an upstream flange (42) and a downstream flange (52). The outer surface (62) of the metal casing (40) is provided with a pattern of blind apertures (66) which extend radially inwardly from the outer surface (62) of the metal casing (40) between the flanges (42,52). The fan blade containment has reduced weight of the metal casing (40) of the fan blade containment assembly (38) for a large diameter turbofan gas turbine engine (10) but has unimpaired stiffness and penetration resistance.

Abstract: The cylindrical compressor casing of a gas turbine engine has a plurality of radially inwardly and axially rearwardly opening anti-surge grooves disposed on a radially inner surface thereof whereby foreign objects ingested into the engine and entering the grooves are free to move axially rearwardly of the engine.

Abstract: A gas turbine engine casing includes a cavity 10 separated from the main flow 12 through the engine by an annular array of tip treatment bars 16. The tip treatment bars 16 are hollow which enables the bars to deform or break upon impact by a shed blade 4 or blade fragment. This allows the blade or blade fragment to pass through the tip treatment bars 16. Blade or blade fragments may then be contained within the cavity 10, or embedded in the casing 2, so preventing further damage to the engine. Entire blades, or large blade fragments, may be able to break through the tip treatment bars 16 and through the engine casing 2 so as to leave the engine entirely, causing the minimum of damage. The interiors of the tip treatment bars may be filled with a damping material, to minimize high cycle fatigue failure.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) has an upstream portion (56), a blade containment portion (54) and a transition portion (58). The upstream portion (56) has a flange (52) connecting the metal containment casing (40) to an axially adjacent casing. The upstream portion (56) of the casing (40) has a greater diameter (D1) than the diameter (D2) of the blade containment portion (54) and the blade containment portion (54) has a greater thickness (T2) than the thickness (T1) of the upstream portion (54). The transition portion (58) connects the blade containment portion (54) and the upstream portion (56) to transmit loads from the blade containment portion (54) to the upstream flange (42).

Abstract: A ducted fan gas turbine engine comprises a fan 12 mounted on a first shaft 16 and a compressor mounted on a second shaft 43. The shafts are coaxial both with each other and with said engine longitudinal axis 15. The shafts are mounted in roller bearings 21, 40. The first bearing 21 carrying the upstream part of the first shaft and the second bearing 40 carrying the upstream part of the second shaft. Both bearings are attached to a structure 26 which comprises an axial sleeve and a front frustoconical portion and a rear radially stiff but axially flexible frustoconical portion and is attached to the engine casing 36. The front frustoconical portion is frangibly attached to the front part of the axial sleeve 28. In the event of damage to the fan the frangible connection breaks and the first shaft is allowed to orbit about the engine longitudinal axis 15. The rear member 32 is swashingly non-linear flexible and accommodates the out of balance radial loads transferred to it as couples during such an incident.

Abstract: An apparatus and method for coupling a device to a semiconductor processing chamber is provided. The apparatus generally comprises a first ring disposed proximate a second ring. An energy dissipating media is disposed between the first and second rings. Upon the application of a torsional force in excess of a predetermined amount, the first ring rotates relative to the second ring. The energy dissipating media absorbs or dissipates some or all the energy applied to the first and second rings.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) has an upstream portion (56), a transition portion (58) and a blade containment portion (54) and a downstream portion (60). The upstream portion (56) has a flange (42) connecting the metal casing (40) to a flange (48) on axially adjacent casing (46). The blade containment portion (54) has a greater thickness (T2) than the thickness (T1) of the upstream portion (54) and the downstream portion (60). The downstream portion (60) has impact protection means (64B) located on its inner surface (62) to protect the downstream portion (60) of the containment casing (40). The impact protection means (64) comprises a plurality of radially inwardly and circumferentially extending ribs (80) on the inner surface (62) of the downstream portion (60) to act as spacer between an inner portion of a detached fan blade (34) and the downstream portion (60).

Abstract: A low pressure turbine shroud includes an arcuate backsheet having opposite mounting rails for engaging a surrounding annular case. The backsheet includes a thicker blade containment shield extending between the rails in a unitary construction. And, a honeycomb rub strip is fixedly joined to the backsheet between the rails.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) has an upstream portion (56), a transition portion (58) and a blade containment portion (54). The upstream portion (56) has a flange (42) connecting the metal casing (40) to a flange (48) on axially adjacent casing (46). The blade containment portion (54) has a greater thickness (T2) than the thickness (T1) of the upstream portion (54). The transition portion (58) connects the blade containment portion (54) and the upstream portion (56) to transmit loads from the blade containment portion (54) to the flange (42) on the upstream portion (56). The ratio of the thickness (T4) of the flange (42) on the upstream portion (56) to the thickness (T1) of the upstream portion (56) is between 3 to 1 and 6 to 1.

Abstract: The cylindrical compressor casing of a gas turbine engine has a plurality of radially inwardly and axially rearwardly opening anti-surge grooves disposed on a radially inner surface thereof whereby foreign objects ingested into said engine and entering said grooves are free to move axially rearwardly of the engine.

Abstract: A bearing support includes a hollow cone diverging between a forward bearing seat and an aft mounting flange. The cone includes an integral annular fuse sized in thickness to fail in shear under abnormal imbalance load transfer between a gas turbine engine fan supported by a bearing in the forward seat and a fan frame mounted to the aft flange.

Abstract: A compressor casing with a volute-shaped flow duct is fastened by means of a rigid fixing arrangement to the bearing casing of the turbomachine, with simple and low-cost means in such a way that the emergence of fragments of a burst compressor impeller from the compressor casing can be prevented. The compressor casing has an outer spiral casing, which surrounds a duct section of the flow duct deflected towards the outside into the radial direction (B), and an inner casing insert piece, which is provided in the radial direction (B) between the spiral casing and the compressor impeller and whose inner contour, together with the outer contour of the hub of the compressor impeller, forms the duct section of the flow duct extending essentially in the axial direction (A).

Abstract: A bearing support for a rotor of an aircraft turbine engine includes a frangible linkage designed to enable the engine to safely shut down despite the introduction of an excessive unbalance to the fan stage.

Abstract: A fan decoupling fuse includes a ring having a row of fuse holes circumferentially spaced apart from each other by fuse ligaments sized to fail under shear when carrying abnormal radial loads from the fan.

Abstract: A protection device for protecting a control mechanism of inlet guide-vanes of a turbojet engine includes a narrowed section on a connecting rod. The connecting rod is for transmitting the movement of a spindle of a piston of the control mechanism or actuator to a control ring that directs all of the inlet guide-vanes. The narrowed section of the connecting rod is a frangible part.

Abstract: A gas turbine engine rotor blade containment assembly (38) comprising a generally cylindrical, or frustoconical, first metal casing (40) and a plurality of generally cylindrical, or frustoconical axially spaced second metal casing is (54, 56 & 58). The second metal casings (54, 56, 58) surrounded and abut the first metal casing (40). The first metal casing (40) is relatively hard and tough to contain a fan blade (34). The second metal casings (54, 56, 58 are relatively soft and lightweight to stiffen the first metal casing (40) and fan blade containment regions (A, B & C). The second metal casing (54, 56, 58) are arranged coaxially with the first metal casing (40). One of the second metal casing means (56) is in a plane (Y) containing the fan blades (34) of the gas turbine engine (10). The first metal casing (40) comprises steel and the second metal casing is (54, 56, 58) comprise aluminum. The fan blade containment assembly (38) is lighter for large diameter turbofan gas turbine engine (10).

Abstract: A casing for the fan section of an aircraft gas turbine engine of the turbofan type. The casing includes an inner filler material and is defined by an outer shell and an inner liner that is spaced radially inwardly from the outer shell. The inner liner is held in position relative to the outer shell by a plurality of radially-inwardly-extending support pins. The pins are carried by the outer shell and are slidably received in and extend at least partially into the inner liner. The support pins retain the inner liner against axial and rotational movement relative to the outer shell, while allowing relative radial movement therebetween in response to thermal expansion and contraction, as well as in response to aircraft maneuver loads imposed on the engine.

Abstract: A frangible cover is provided for a recess in a containment case for turbofan engine blade removal and access. The recess provided in the containment case allows outward radial movement of the engine fan blade when the engine fan blade is to be removed from the containment case. The present invention proposes a frangible component to cover the recess. A plurality of initiation points, notched in the frangible cover at intersections of surfaces encourages brittle fracture of the frangible component.

Abstract: A turbofan gas turbine engine (10) comprises a fan rotor (32) carrying a plurality of radially extending fan blades (34). A fan blade containment assembly (38) surrounds the fan blades (34) and the fan blade containment assembly (38) comprises a generally cylindrical, or frustoconical, metal casing (40). The casing (40) comprises an annular hook (54) positioned axially upstream of the tip (37) of the fan blade (34). The annular hook (54) extends in a radially inwardly and axially downstream direction from the metal casing (40) towards the tip (37) of the fan blade (34). The metal casing (40) has a containment portion (A) downstream of the annular hook (54) and substantially in the plane of the leading edge of the tip (37) of the fan blade (34). The containment portion (A) of the casing (40) has a greater diameter than the diameter of the casing (40) at the annular hook (54) to restrain upstream movement of a detached fan blade (34).

Abstract: A fan case for a turbofan engine having a fan including plurality of fan blades mounted to a rotor disk and a decoupler that fails in response to a predetermined load includes a substantially annular shell. The shell has a forward section, an intermediate section, and an aft section. The fan case further includes an aft facing step formed at the forward end of the intermediate section to prevent blade fragments from being ejected forward. The intermediate section is axially aligned with the fan and has a large inside diameter. The intermediate section thus defines an annular space around the fan blades that is sufficiently large to allow the fan to orbit when the decoupler fails. The intermediate section and the aft section are aligned radially to allow blade fragments to be ejected aft, avoiding additional secondary blade damage.

Abstract: A turbo-molecular pump of high safety and reliability has been developed so that if an abnormal condition should develop on the rotor structure, it will not lead to damage to the stator or pump casing to cause loss of vacuum in a vacuum processing system. The turbo-molecular pump comprises a pump casing housing a stator and a rotor therein, a vane pumping section and/or a groove pumping section comprised by the stator and the rotor, and a constriction releasing structure for releasing constriction of at least a part of the stator when an abnormal torque is applied to the stator by the rotor.

Abstract: A windmilling brake system for a turbine engine includes a brake drum (14) on an interior surface of an engine rotor. The drum circumscribes a brake unit (37) that includes a brake ring (38) with brake shoes (42) each connected to the ring by respective springs (44). A leg (45) extends from each shoe and toward the ring. The ring is sandwiched axially between bolting flanges (28, 29) on forward and aft carrier portions (24, 25) of a two piece, variable stiffness, dual load path rotor bearing support. Nonsacrificial fasteners secure the ring to one of the flanges while frangible fasteners (52) secure the flanges to each other. The frangible fasteners also extend through an eye (47) in each leg to deflect the springs and hold the brake shoes in an armed state out of contact with the drum. Upon being exposed to abnormal imbalance loads, the frangible fasteners fail in tension to disable one of the two load paths.

Abstract: A gas turbine engine core casing comprises axially adjacent portions (20,21) that are flanged to receive bolts (28) that attach the portions (20,21) to each other. One of the casing portions (20) is provided with flange (23) that is of L-shape cross-section to provide local enhancement of the rigidity of the casing portion (20). Such rigidity enhancement provides improved debris containment in the event of the failure of rotor components within the casing.

Abstract: A frangible cover is provided for a recess in a containment case for turbofan engine blade removal and access. The recess provided in the containment case allows outward radial movement of the engine fan blade when the engine fan blade is to be removed from the containment case. The present invention proposes a frangible component to cover the recess. A plurality of initiation points, notched in the frangible cover at intersections of surfaces encourages brittle fracture of the frangible component.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) has an upstream portion (56), a blade containment portion (54) and a transition portion (58). The upstream portion (56) has a flange (52) connecting the metal containment casing (40) to an axially adjacent casing ( ). The upstream portion (56) of the casing (40) has a greater diameter (D1) than the diameter (D2) of the blade containment portion (54) and the blade containment portion (54) has a greater thickness (T2) than the thickness (T1) of the upstream portion (54). The transition portion (58) connects the blade containment portion (54) and the upstream portion (56) to transmit loads from the blade containment portion (54) to the upstream flange (52).

Abstract: An improved containment structure for use with turbomachinery, such as turbofan engines. A casing is provided with at least one impact resistant section of a thickness sufficient to resist being pierced upon impact by a blade. The impact resistant section has a smoothly contoured thickness along its axial length and is free from features likely to cause a local failure in the event of impact by a blade released from a rotating disk.

Abstract: A pressure relief device for preventing over pressurization of a propeller hub is disclosed. The pressure relief devices is designed to fit within a ball hole opening in the hub arm of the hub. The pressure relief device includes a housing which sealably interfaces with an inner wall of the ball hole opening and a pressure relief insert which sealably interfaces with the housing. The pressure relief device includes a plurality of fracture tabs which engage an end of the housing exposed to hub cavity pressure. The fracture tabs are designed to break at a design pressure allowing the pressure relief insert to be forced out of the housing thus breaking the seal between the pressure relief insert and housing thereby venting the hub cavity.

Abstract: A centripetal compressor includes a compressor housing, a compressor wheel mounted within the housing and having compressor blades. The compressor housing comprises a cover plate and a diffuser flange that is fixed to both the cover plate and to a bearing housing. The diffuser member has an outer peripheral portion attached to the cover plate and a radially inner portion attached to the bearing housing. A frangible groove or weakened section is defined in the diffuser at a position intermediate the outer peripheral and the radially inner portions so as to enable predictable fracture of the diffuser flange during failure of the compressor wheel. The same principle is applied to the turbine of a turbocharger.

Abstract: 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.

Abstract: The present invention relates to an impeller containment system for containing the burst of an impeller or the burst of impeller fragments from an impeller hub. The containment system utilizes a catcher extending from a shroud plate adjacent the impeller, which engages with a snagger formed as a unitary part of the impeller. The catcher and snagger cooperate to restrain a burst impeller or impeller fragments to their shortest radial distance from their point of burst. The system also includes a shroud which circumferentially surrounds the impeller and a diffuser, which circumferentially surrounds the radial tip portions of the impeller.

Abstract: A platform for a turbofan gas turbine engine that does not limit the rotation capability of adjacent fan blades in the event one of the fan blades is impacted by a foreign object. The platform includes a structural body portion and an integrally formed flowpath surface portion. The structural body portion has a contour that matches that of the adjacent fan blades. The flowpath surface portion defines a pair of wings that extend laterally beyond the structural body portion. The wings are frangible so as to break off if an adjacent fan blade rotates in response to an ingestion event. The platform is made from a composite material using a resin transfer molding process.

Abstract: An improved rotary engine, engine lining and engine casing and lining combination are disclosed. The engine is preferable a turbofan engine and includes a fan blade, rotatably mounted within a generally cylindrical casing for rotation about a lengthwise extending central axis. An annular lining is mounted within the casing between a tip of the fan blade and the casing. The lining seals the tip of the fan blade within the casing. The lining includes a brush seal that extends around an inner circumference of the casing, and has a plurality of bristles that extend radially inward from the seal. A retaining membrane extends around the brush seal, preventing the bristles from extending substantially in a radial direction from the brush seal. The retaining membrane is adapted to release the bristles to extend radially inward to occupy a region between the tip of the fan blade and the casing upon a radial excursion of the fan blade.

Abstract: A blade containment structure for turbomachinery, such as a high bypass turbofan engine. The blade containment structure includes a first casing member having a wall that defines an inner containment shell that immediately surrounds the blades of the turbomachine, and a second casing member assembled to the first casing member. The second casing member has a wall that defines an outer containment shell that surrounds the inner containment shell, such that a cavity is defined by and between the inner and outer containment shells. The first casing member is formed from a high-toughness material such as steel or a nickel-base alloy, while the second casing member is formed from a lower-weight and potentially lower-toughness material as compared to the material of the first casing member.

Abstract: A containment casing for a gas turbine engine comprising a substantially rigid casing shell arranged in operation coaxially with an axis of rotation of the gas turbine engine. The casing extending circumferentially around an array of fan rotor blades which are arranged to rotate about the engine axis. In the region of the casing where it is predicted blade impact in the event of a fan blade failure, there is at least one reinforcing rib extending substantially radially from the casing and circumscribing the outer periphery of the casing shell. The ribs providing improved strengthening of the casing. Preferably a first rib is positioned about the casing between the operational position of the trailing edge and the mid chord point of the fan blade. A second rib is axially positioned between the operational position of the mid chord point and the leading edge of the fan blade. A third rib may also be positioned axially forward of the operational position of the leading edge of the fan blade.

Abstract: 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.