Abstract: A gas turbine engine rotor blade containment assembly (38) comprises a containment casing (40) and the containment casing (40) has a plurality of axially spaced ribs (66). The ribs (66) extend circumferentially and radially inwardly from the containment casing (40) to define a plurality of circumferentially extending grooves (76) and a perforate sheet (70) is secured to the radially inner ends (68) of the ribs (66). In the arrangement of the present invention the blade containment function and the acoustic treatment function are combined.

Abstract: A tension decoupler includes first frangible rupture members, arranged in parallel to each other, and second structural rupture members, arranged in parallel to each other and parallel to the first rupture members. The frangible rupture members and the structural rupture members are designed to break only when the load applied to the decoupler device reaches or exceeds a predetermined load value, and the structural rupture members are designed to have sufficient fatigue strength as long as the applied load does not reach the predetermined load value.

Abstract: The turbine engine of the invention includes a rotor with at least one bearing, mounted on a bearing supporting part, said part being connected to the fixed structure by an uncoupling device, including at least one fusible screw passing through at least one bore, said screw comprising a head and a threaded portion, a fusible portion forming a preferential failure area, located between the head of the screw and its threaded portion. The screw comprises, between its threaded portion and its fusible portion, a portion for blocking the screw in rotation, cooperating with a complementary blocking portion provided in the bore. By means of the invention, the torsional torque related to the tightening of the screw is not transmitted to its fusible portion.

Abstract: A turbine engine fan casing for containing a separated blade fragment comprising a support case having an axially extending impact zone, a substantially structurally continuous penetrable covering circumscribing the impact zone; and a containment covering circumscribing the penetrable covering. The containment covering comprises a textile fabric containing threads in a warp direction and a fill direction, wherein the threads in the warp direction are of a different denier than the threads in the fill direction.

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 member (54) positioned axially upstream of the tip (37) of the fan blade (34). The annular member (54) extends in a radially inwardly and axially downstream direction from the metal casing (40) towards the tip (37) of the fan blade (34). A set of acoustic panels (72C) is also provided. A set of acoustic panels (72B) is secured to the metal casing (40) by resilient fingers (80, 84) on the upstream and downstream ends (82,86) of the acoustic panels (72B) which locate on the annular member (54) and the acoustic panels (72C).

Abstract: A composite fan casing for a gas turbine engine is provided includes, in an exemplary embodiment, a core having a plurality of core layers of reinforcing fiber bonded together with a thermosetting polymeric resin. Each core layer includes a plurality of braided reinforcing fibers with the braids of reinforcing fibers aligned in a circumferential direction.

Abstract: The invention relates to a turbomachine comprising a rotor with a drive shaft centered on the axis of the turbomachine by a first bearing and a second bearing which bearings are supported respectively by a first-bearing-support piece and a second-bearing-support piece which are secured to one another and connected to the turbomachine fixed structure by a decoupling device. This turbomachine comprises means designed to collaborate with at least one element of the turbomachine fixed structure in order to perform a dual function, that of preventing the bearing supports, from rotating and that of radially retaining the drive shaft in the event of the bearings becoming decoupled.

Abstract: A gas turbine engine rotor blade containment assembly (38) comprises a generally cylindrical, or frustoconical, metal casing (40). The metal casing (40) has at least one arched portion (62, 64, 66) and each arched portion (62, 64, 66) extends circumferentially around the metal casing (40). Each arched portion (62, 64, 66) comprises a radially inwardly extending arch (68) in which the trough (74) of the arch (68) is radially inwardly of a straight line (76) interconnecting the axial ends (70, 72) of the arch (68). The trough (74) of the arch (68) is radially inwardly of the at least one of the axial ends (70, 72) of the at least one arch (68). The arched portions (62, 64, 66) introduce compressive stresses into the metal casing (40) during a fan blade 34 impact and enable the metal casing (40) to withstand the impact. The fan blade containment assembly (38) is lighter for large diameter turbofan gas turbine engine (10).

Abstract: A mechanical arrangement for protection against catastrophic nozzle failures includes a turbine nozzle segment including an inner platform rail, a turbine nozzle inner support ring in part in axial registration with the rail on one side, an inner retainer segment secured to the inner support ring and in part in axially spaced registration relative to the rail on an axial side of the rail opposite from the support ring, a first inclined conical surface on the inner retainer segment, and a second inclined conical surface on the inner platform rail of the turbine nozzle, the second inclined conical surface opposing the first inclined conical surface, so as to bind the inner platform rail to the turbine nozzle between the inner retainer segment and the inner support ring, resulting in a wedge lock that prevents the inner platform from being lost downstream into rotating hardware of the turbine.

Abstract: A turbofan gas turbine engine (10) comprises a fan rotor and a compressor rotor (62). The fan rotor (24) carries a plurality of circumferentially spaced radially outwardly extending fan blades (26). The compressor rotor carries a plurality of circumferentially spaced radially outwardly extending compressor blades (64). The fan rotor (24) is mounted on a fan shaft (38) and the compressor rotor (62) is mounted on a compressor shaft (68). The compressor shaft (68) is arranged around the fan shaft (38). The fan rotor (24) is rotatably mounted on a support structure (40) by a first bearing (50) and the compressor rotor (62) is rotatably mounted on the support structure (40) by a second bearing (58) spaced axially from the first bearing (50). The fan and compressor rotors (24, 62) are normally arranged coaxially with each other and with the support structure (40).

Abstract: A turbine assembly includes a shroud for being mounted around a last stage of the low pressure turbine rotor. The shroud includes an arcuate body having spaced-apart forward and aft ends and spaced-apart circumferential ends. Attachments are provided for securing the shroud body to the surrounding engine case. An arcuate extension member protrudes rearward from the aft end of the shroud body. The extension member has an inner surface which defines a portion of the gas flowpath through the engine. Seals may be provided to prevent leakage between adjacent shroud segments. The shroud is especially useful for protecting a downstream turbine frame from debris and thermal stress.

Abstract: A turbine including a rotor (1) that is driven by gas and that has a housing (2) enclosing the rotor. The turbine includes a component (6) suspended from the housing (2) that is arranged inside the housing (2) and at least partially beside the rotor (1) with respect to the direction (5) of the gas flow in order to impede any fragments which may come loose from the rotor from penetrating the housing in radial direction.

Abstract: A structural member comprises a main body formed from a cellular material. The structural member may be a casing for a rotary assembly e.g. a fan of a gas turbine engine. The main body may incorporate strengthening ribs and conduits and may have a random or graduated arrangement of different sized cells forming the cellular material. A recess may be defined on the radially inner face of the main body to receive an abradable material suitable for forming a seal with the blades of the fan.

Abstract: A device, system, and method for securing a turbine engine seal in a retracted position enabling maintenance, assembly and disassembly of the turbine engine. The system can include a retainer arranged to retain the seal in a retracted position and constructed to fail at an engine operating temperature. Failure of the retainer allows movement of the seal from the retracted position to an operational position.

Abstract: An aircraft turbojet including a fan having a hub driven by a shaft carried by at least one bearing connected to the structure of the turbojet by a bearing support that includes an interposed decoupling device. The hub carries at its periphery a plurality of blades that move inside a retention casing with radial clearance E between the tips of the blades and an inside wall of the retention casing. The inside wall is lined in a layer of abradable material suitable for being planed away by the tips of the rotating blades. The tips of the blades are suitable for being disintegrated by the inside wall of the retention casing in the event of an impact following the appearance of unbalance that has led to the bearing being decoupled, to obtain a clearance J>E as required for operation of the decoupler.

Abstract: Percussive impacts due to bird strikes upon the hollow fan blades 20 are a well known problem. These percussive impacts not only deform previous fan blades but also reduce their stiffness. In accordance with the present invention, hollow fan blades 20 incorporate a cavity 23 within which, a matrix 24 with embedded expandable elements 25, is located. Thus, upon a percussive impact these expandable elements 25 are released in order to create an internal pressure within the cavity 25 which acts outwardly in order to relieve deformation and also stiffen the blade 20 as a result of the over pressure within the cavity 23.

Abstract: To further isolate imbalances in a rotating structure such as a gas turbine engine, an effective length between two bearings may exceed an actual length. This may be achieved via one or more tapering bearing supports associated with at least one of the bearings.

Abstract: A bearing support for a rotor of an aircraft turbine engine which includes a front bearing and a front bearing support and bearing strut for securely attaching the front bearing, to the aircraft turbine engine support structure, wherein the front bearing support and bearing strut are integral with the aircraft turbine engine support structure.

Abstract: A protective ring (4) for the fan blades (2, 3) of a gas turbine engine includes a material combination of metal bands and polymer-bonded fiber-weave layers interconnected in alternating arrangement. The protective ring thus formed, which is characterized by tough-elastic properties and low weight, can be used as a full containment (4?) with sufficiently large wall thickness or as a penetration containment (4?) with smaller wall thickness and with a trapping layer arranged on the outer circumference. As a full containment, the protective ring has impact-absorption capacity, as a penetration containment it prevents a further destruction of the broken-through protective ring.

Abstract: In an emergency cooling system (17) for a component (1) which is subject to thermal load in operation, in, e.g., a turbine, the component (1) has a wall (3) which, in operation, is acted on by heat on a first wall side (14) and is acted on by a flow of cooling fluid (11) on a second wall side (15). The wall (3) has at least one emergency cooling opening (12) which is closed off by a plug (16) and through which cooling fluid flows from the second wall side (15) to the first wall side (14) when the plug (16) is absent. The plug (16) is designed so as to melt at a predetermined temperature. The plug (16) is a body which is produced separately from the component (1), the plug (16) being inserted into the emergency cooling opening (12), in which it is connected to the component (1).

Abstract: A molecular pump has a casing having a gas inlet port and a gas discharge port, a stator disposed within the casing, a shaft disposed in the casing concentrically with the stator, a bearing rotatably supporting the shaft for undergoing rotation relative to the stator in a preselected direction of rotation, a rotor mounted on the shaft for rotation therewith in the preselected direction of rotation, and a motor for rotationally driving the shaft. A flange is connected to the casing at the gas inlet port.

Abstract: A frangible coupling for interconnecting parts comprising a first ring and a second ring coaxially arranged relative to each other and axially joined via an annular array of fuse ligaments equidistantly spaced apart from each other. The ligaments are configured to fail when an abnormal radial load of a predetermined value causes the first and second ring to move out of their coaxial relationship. When all of the fuse ligaments are severed, the communication between the first and second rings is severed. This allows the first ring to move independently of the second ring, preventing the out of balance load on the first ring being communicated to the second ring.

Abstract: An ultra-high speed vacuum pump evacuation system includes a first stage ultra-high speed turbofan and a second stage conventional turbomolecular pump. The turbofan is either connected in series to a chamber to be evacuated, or is optionally disposed entirely within the chamber. The turbofan employs large diameter rotor blades operating at high linear blade velocity to impart an ultra-high pumping speed to a fluid. The second stage turbomolecular pump is fluidly connected downstream from the first stage turbofan. In operation, the first stage turbofan operates in a pre-existing vacuum, with the fluid asserting only small axial forces upon the rotor blades. The turbofan imparts a velocity to fluid particles towards an outlet at a high volume rate, but moderate compression ratio. The second stage conventional turbomolecular pump then compresses the fluid to pressures for evacuation by a roughing pump.

Abstract: A method facilitates fabricating a gas turbine engine. The method comprises coupling an engine casing circumferentially around a gas turbine engine. The method also comprises coupling an engine containment wrap to the gas turbine engine, such that the containment wrap circumscribes at least a portion of the gas turbine engine casing, wherein the containment wrap includes a plurality of layers coupled together such that a first layer is formed from at least three sheets coupled together such that the first sheet fibers are oriented substantially in a first direction, such that the second sheet fibers are oriented in a second direction that is offset approximately forty-five degrees from the first sheet, and such that the third sheet fibers are oriented substantially parallel to the first direction, and wherein the plurality of first sheet fibers are aligned substantially axially with the respect to the turbine engine.

Abstract: A compressor in a multi-stage axial form of construction, with a rotor which is mounted overhung and includes a plurality of moving-blade rings on blade carriers connected to one another, and with a blade arrangement, in which the moving-blade ring of the first stage forms the blade cascade arranged furthest upstream. At least one of the rotating blade carriers is produced in an MMC form of construction, that is to say as a metal component fiber-reinforced at least in regions, and the rotary bearing absorbing the large part of the radial loads occurring on the rotor has a predetermined breaking point which, when a defined radial load is exceeded, allows a radial shift of the rotor, with the result that the latter brushes against the stator.

Abstract: A containment device for use in retaining debris material traveling radially outward in a rotary device is provided as is a turbine having a containment device. The containment device includes an outer ring that extends generally circumferentially and defines an inner surface directed radially inward. A plurality of energy absorption elements are disposed on the inner surface of the outer ring. Each absorption element extends both radially inward and circumferentially so that each absorption element is configured to be plastically deformed radially outward by debris material impacting the absorption element. Each absorption element can include a base and a cap, the base extending in a generally radial direction and the cap being connected to the radially inward end of the respective base and defining an angle therewith.

Abstract: An electronic safety system for the detection of a shaft failure and for the interruption of the energy supply to the shaft includes at least one measuring light guide (13) which is firmly routed in the shaft longitudinal direction, co-rotates with the shaft (1) and is connected to a light source (18) on a light inlet side (14). In the event of a shaft failure, the measuring light guide will break to diminish light transmission therethrough, with the absence of light on a light outlet side (15) being detected by an optical sensor (19) and being used, via evaluation and control electronics (20, 21), as a signal for the shut-off of the further energy supply at a fuel shut-off valve (22). The measuring light guide is fixed to a measuring sleeve (4) attached at both ends to the shaft.

Abstract: A burst protector for a turbocharger covers a first endangered segment of the housing. The burst protector includes insulation, a first sheet, and a second sheet. As a supplement, a casing is installed around the burst protector. The safety of a turbocharger in operation is increased by the invention.

Abstract: A stub shaft for a turbine engine is described in which respective masses are positioned along the stub shaft in a balanced rotation relationship for normal rotation. One mass is positioned at the periphery of a shaft end rim such that upon failure of the stub shaft this mass is detached. Such displacement or detachment of the mass causes imbalance which creates vibration which in turn causes surge within a compressor associated with the stub shaft as well as possibly interference engagement with stable structure elements in order to limit turbine and/or compressor over speed.

Abstract: An engine fan containment shroud including a containment structure composed of a composite material including a reinforcing fiber having an elongation to break of at least about 3.6%. The preferred fiber is a quartz fiber having an elongation to break of at least about 5%. Additionally or alternatively, the reinforcing fiber, in particular quartz fiber, has a hardness of at least about 4 on the Mohs scale, as measured on bulk material, which resists cutting by an impacting object. The composite material and specifically an epoxy/quartz fiber composite provides for weight reduction while providing fan blade containment without loss of structural integrity and with improved resistance to impact and puncture.

Abstract: A structural member comprises a main body formed from a cellular material. The structural member may be a casing for a rotary assembly e.g. a fan of a gas turbine engine. The main body may incorporate strengthening ribs and conduits and may have a random or graduated arrangement of different sized cells forming the cellular material. A recess may be defined on the radially inner face of the main body to receive an abradable material suitable for forming a seal with the blades of the fan.

Abstract: A very safe and reliable turbo-molecular pump 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 a loss of vacuum in a vacuum processing system. The turbo-molecular pump has a pump casing housing a stator and a rotor therein, a vane pumping section and/or a groove pumping section formed by the stator and the rotor, and a constriction releasing structure for releasing the constriction of at least a part of the stator when an abnormal torque is applied to the stator by the rotor.

Abstract: A turbo-molecular pump of high safety and reliability was presented, so that if an abnormal condition should develop on the rotor side, it will not lead to any damage to the stationary portions such as the stator or pump casing to cause loss of vacuum in a vacuum processing system. The turbo-molecular pump includes a rotor; a stator assembly surrounding the rotor; and a casing portion surrounding the stator assembly, wherein at least a partial clearance is formed between the stator assembly and the casing portion, so that, when an abnormal torque is applied from the rotor to the stator assembly, direct impact transmission is prevented from the stator assembly to the casing portion.

Abstract: A gas turbine engine rotor blade containment assembly comprises a generally cylindrical, or frustoconical, stiff containment casing (54), a generally cylindrical, or frustoconical, flexible structure (62) arranged within and spaced radially from the stiff containment casing (54) by crushable structures (64, 66) at axially spaced positions on the flexible structure (62). A viscoelastic material (68) is arranged to fill the space (70) between the stiff containment casing (54), the flexible structure (62) and the crushable structures (64, 66). The viscoelastic material (68) provides local stiffening of the blade containment assembly in the region of a fan blade (34) impact and provides energy dissipation by viscoelastic damping of the flexing of the flexible structure (62) and plastic deformation in the crushing of the crushable structures (64, 66).

Abstract: A system for decoupling a fan of a turbojet, the turbojet including a moving fan shaft mounted on bearings each connected to a stationary structure of the turbojet by bearing supports, the bearing supports being fixed to the stationary structure of the turbojet via mechanical links serving, during normal operation of the turbojet, to transmit the forces generated by rotation of the fan, the mechanical links include explosive charges enabling the links to be broken, the explosive charges being controlled by a full authority digital engine control computer on the basis of means for measuring the mechanical stresses in the turbojet and of a computer model simulating the static, dynamic, and thermodynamic behavior of the turbojet.

Abstract: A method for assembling a turbine engine including an exhaust diffuser extending aftward from exhaust casing, wherein the method includes coupling a relief diaphragm to the exhaust diffuser and coupling a guide system to the exhaust diffuser such that the guide system is radially inward from the relief diaphragm and defines at least a portion of the exhaust flow path through the exhaust diffuser.

Abstract: A flexible jacket for a vacuum blower having rotatable blades in a blade housing. The jacket is made from heavy duty, substantially impenetrable, bullet resistant material such as KEVLAR brand sheet material which is placed about the blade housing to prevent any severed and flying rotor blades from entering the atmosphere through the blade housing. The configuration of the jacket is formed to match the blade housing and to enable the jacket to be easily retro-fitted onto existing vacuum blowers or other blade housings and secured in place about the blade housing.

Abstract: A joint assembly for limiting an extension of the joint in the direction of a load path derived from an impact comprising a first member having a portion and a second member having a portion, the portions overlapping one another and arranged generally parallel to one another and secured together via securing means disposed through corresponding holes defined therein. One of the overlapping portions further defines, sequentially in the direction of extension, a shear neck, a pocket and a catcher portion. In the event of a worst-case impact load the securing means shears through the shear neck and the pocket and is arrested by the catcher portion, thereby the extension of the joint assembly is limited and the joint assembly remains integral.

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 turbofan gas turbine engine (10) comprises a fan rotor and a compressor rotor (62). The fan rotor (24) carries a plurality of circumferentially spaced radially outwardly extending fan blades (26). The compressor rotor carries a plurality of circumferentially spaced radially outwardly extending compressor blades (64). The fan rotor (24) is mounted on a fan shaft (38) and the compressor rotor (62) is mounted on a compressor shaft (68). The compressor shaft (68) is arranged around the fan shaft (38). The fan rotor (24) is rotatably mounted on a support structure (40) by a first bearing (50) and the compressor rotor (62) is rotatably mounted on the support structure (40) by a second bearing (58) spaced axially from the first bearing (50). The fan and compressor rotors (24, 62) are normally arranged coaxially with each other and with the support structure (40).

Abstract: A vacuum pump is removably connected to the underside of a chamber for exhausting gas molecules from the chamber. The vacuum pump has a pump case having a flange extending circumferentially around a top portion thereof, a suction port and an exhaust port. Stator blades are fixedly mounted within the pump case, and a rotor is rotatably mounted in the pump case and has rotor blades alternately disposed with respect to the stator blades. A driving motor rotationally drives the rotor so that the rotating rotor blades coact with the stator blades to evacuate gas molecules from the chamber and pump the gas molecules from the suction port to the exhaust port. Bolt insertion holes are formed in the flange and each hole has a smaller diameter portion opening at a lower surface of the flange and a larger diameter portion opening at an upper surface of the flange which faces the underside of the chamber.

Abstract: The present invention provides a vacuum pump which reduces a damaging torque produced when a rotor rotating at high-speed crashes into a screw stator or the like. The vacuum pump has a rigid ring disposed around the screw stator such that a shock load from the screw stator causes the rigid ring to rotate. When a brittle facture occurs in the rotor rotating at high-speed, for example, and a part of the rotor crashes into the screw stator, a rotating torque, i.e., a damaging torque causing the entire vacuum pump to rotate is likely to occur. However, this damaging torque is absorbed by the rotation of the rigid ring and eventually subsides.

Abstract: The invention provides a device for supporting and recentering a shaft (2) after decoupling. The device comprises an annular support (4) surrounding the shaft (2), a bearing (5) secured to the annular support (4) and having an inner ring (9) which is spaced apart from the shaft by clearance J. The inner ring (9) has two webs or tenons (14a, 14b) that are normally held to the periphery of two troughs (16a, 16b) carried by the shaft (2). Two sets of balls (28a, 28b) normally bear against the bottoms of indentations (25, 26) formed facing one another in the adjacent radial walls of the troughs (16a, 16b) and of the inner ring (9). Resilient means (26) tend to urge the troughs (16a and 16b) towards each other. In the event of the webs or tenons (14a, 14b) breaking due to a large unbalance, the balls (28a, 28b) roll on the walls of the indentations (25, 26) and move the troughs (16a, 16b) apart from each other.

Abstract: A bearing assembly for a gas turbine engine rotor includes a paired race, a bearing, a mounting joint, and a plurality of mechanical fuses. The paired race includes an outer race and an inner race. The bearing is between the inner and outer races, and is configured to support the rotor on a support frame. The mounting joint includes a joint inner race and a joint outer race. At least one of the joint inner race and the joint outer race includes a spherical surface. The mounting joint is configured to reduce dynamic loads to the gas turbine engine structure and static bending to the rotor. The plurality of mechanical fuses extend through at least one of the joint inner race and the joint outer race.

Abstract: A system for decoupling a fan of a turbojet, the turbojet including a moving fan shaft mounted on bearings each connected to a stationary structure of the turbojet by bearing supports, the bearing supports being fixed to the stationary structure of the turbojet via mechanical links serving, during normal operation of the turbojet, to transmit the forces generated by rotation of the fan, the mechanical links include explosive charges enabling the links to be broken, the explosive charges being controlled by a full authority digital engine control computer on the basis of means for measuring the mechanical stresses in the turbojet and of a computer model simulating the static, dynamic, and thermodynamic behavior of the turbojet.

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 (64) 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 jet aircraft fan case containment design that uses polyurethane to absorb fan blade fragments and uses polyurethane to prevent fan blade fragments from penetrating the fan case. The polyurethane is used in place of or to supplement KEVLAR® and/or fiberglass wraps used to contain fan blade fragments. The polyurethane is also used in place of aluminum alloy and stiffening ribs in the fan case.

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 flexible jacket for a vacuum blower having rotatable blades in a blade housing. The jacket is made from heavy duty, substantially impenetrable, bullet resistant material such as KEVLAR brand sheet material which is placed about the blade housing to prevent any severed and flying rotor blades from entering the atmosphere through the blade housing. The configuration of the jacket is formed to match the blade housing and to enable the jacket to be easily retrofitted onto existing vacuum blowers or other blade housings and secured in place about the blade housing.

Abstract: To provide a vacuum pump used for semiconductor manufacturing, which has improved reliability and safety and in which damages to a pump casing, peripheral apparatuses, or the like are prevented from occurring by preventing the occurrence of rotor breakage due to corrosion. A balancer is provided in the outer circumferential surface of the rotor so as to face the inside of the gas passageway. A balancer main body is supported against the outer circumferential surface of a rotor through a fragile portion that is weak with respect to corrosive gasses, the fragile portion of the balancer is damaged by corrosion before any corrosive gas influence appears in rotor blades or the rotor, and the balancer falls off, thus forcibly causing an unbalanced state to appear in the rotor. The balancer thus possesses a function for balancing the rotor and a corrosion detecting function.