Abstract: A joint assembly for an annular structure comprises a first annular member having a first radially extending flange and a second annular member having a second radially extending flange. The first and second flanges having a plurality of first and second circumferentially aligned apertures. A plurality of fasteners are provided and each fastener is arranged to extend through a respective pair of the first and second apertures to join the first and second annular members together. The first and second radially extending flanges have a plurality of circumferentially aligned third and fourth apertures. A plurality of members are provided and each member is arranged to extend axially through a respective pair of the third and fourth apertures.

Abstract: The invention provides an alloy steel having the following composition: Ni 5-14 wt %; Cr 4-16 wt %; Co 7-14 wt %; Mo 1-5 wt %; W 0-5 wt %; Ti 0-0.8 wt %; Al 0.1-3 wt %; the balance being Fe save for incidental impurities. This provides an ultra-high strength corrosion resistant steel with good toughness, which does not significantly creep at temperatures up to 450° C. The high quantity of alloying to elements, particularly chromium, also gives the alloy good corrosion resistance. The alloy is particularly suitable for main shafts of gas turbine engines.

Abstract: A turbomachine casing assembly includes a first casing element locatable radially outward of one or more rotating aerofoil elements of a turbomachine, a second casing element located radially distal to the first casing element. A void is provided between a radially proximal face of the first casing element and a radially proximal face of the second casing element, at the first end of the first casing element. The first end of the first casing element is located against a corresponding first end of the second casing element by an energy absorbing element, with the first casing element; including a cantilever. The cantilever is arranged in a region extending along the first casing element from the first end; and having a pivot axis at a mid portion thereof.

Abstract: A leaf seal for effecting a seal between coaxials and relatively rotating components. The seal has annular pack of stacked leaves, the pack mountable to first one of components at leaves root portions and extending towards other component end edges of leaves presented for air-riding interaction with other component during relative rotation between components. In use, pressure drop is maintained axially across the pack, which includes first set of leaves arranged around the pack, each to present an end edge at least part in relationship with other component. The pack includes second set of leaves circumferentially interspersed throughout the first set. The first and second sets, leaves help define, around the pack, circumferential spaces between end edges of first set's successive leaves, the spaces create circumferential variation in pressure around the pack contributing to the generation of hydrodynamic lift between pack and other component during relative rotation between components.

Abstract: An aerofoil component of a gas turbine engine is provided. The component has a longitudinally extending aerofoil portion which spans, in use, a working gas annulus of the engine. The aerofoil portion contains an internal chamber for a flow of coolant. The chamber includes a helical passage which spirals in a plurality of turns around an axis that extends in the length direction of the aerofoil portion.

Abstract: A method of reducing dynamic imbalance in a bladed rotor assembly by axially adjusting one or more of the blades so as to redistribute mass along the geometric axis of the assembly. The blades may be axially adjusted to form a counterbalancing couple. Additional correction masses may be added for supplemental correction of couple imbalance or residual static imbalance in the bladed rotor assembly. The invention offers a reduction in the weight penalty associated with conventional balancing corrections carried out on the bladed rotor assembly.

Abstract: Invention concerns a machine fault diagnostic system. Sensors are provided for sensing an operational parameter of the machine over time in use and outputting corresponding sensor signals. A machine operation diagnosis tool is arranged to receive the sensor signals and has a data store for operational parameter data indicative of a normal mode of machine operation and operational parameter data indicative of one or more known machine faults. The diagnosis tool has one or more processor arranged to compare the received sensor signals with the operational parameter data in the data store in order to determine a match with either the normal mode of operation or the one or more known machine fault, and wherein the processor sentences an unknown fault in the event that said match is not established. The system may record unknown faults and update the diagnosis tool as unknown faults become recognizable faults.

Abstract: A magnetic shielding arrangement, including: at least one magnetic flux source; a superconductor magnetic shield at least partially surrounding the magnetic flux source; a second shield at least partially surrounding the superconductor magnetic shield.

Abstract: An electrical assembly including electrical raft having electrical conductors embedded in a rigid material is provided. The electrical assembly has an electrically conductive screen layer. The electrically conductive screen layer provides electromagnetic protection to the electrical conductors. The electrically conductive screen layer is electrically connected to a mounting fixture, which in turn may be electrically connected to an apparatus on which the electrical assembly may be mounted. The electrical raft is used to transport electrical signals (which may be, for example power and/or control signals), for example around a gas turbine engine.

Abstract: A hot isostatic pressing tool includes a plurality of canister members and the hot isostatic pressing tool including at least one set of adjacent canister members. The plurality of canister members form a chamber to receive a powder material to be hot isostatically pressed. The at least one set of adjacent canister members have interlocking features forming a U-shaped, or a Z-shaped, leakage flow path between the at least one set of adjacent second canister members. The adjacent canister members are welded together to form a joint and the U-shaped, or Z-shaped, leakage flow path reduces the likelihood of failure of the welded joint during hot isostatic pressing.

Abstract: An aerofoil blade or vane for the turbine of a gas turbine engine is provided. The blade or vane includes an aerofoil portion which, in use, extends radially across a working gas annulus of the engine. A coolant inlet is formed at an end of the aerofoil portion for the entry of a cooling air flow into the portion. A corresponding coolant exhaust is formed at the trailing edge of the aerofoil portion for spent cooling air to flow from the portion. A passage within the aerofoil portion connects the inlet to the exhaust. A fence within the aerofoil portion extends radially and forwardly from a start position at the end of the aerofoil portion adjacent the trailing edge to an end position. The passage forms a loop which extends along one side of the fence, wraps around the end position, and extends along the other side of the fence.

Abstract: A nose cone assembly 102 is disclosed, comprising a one piece nose cone 104 and a support ring 106 on which the nose cone 104 is mounted. The support ring 106 comprises a plurality of circumferentially distributed resilient attachment tabs 114, via which the nose cone 104 is mounted on the support ring 106. The support ring 106 further comprises a load spreader 122, and each of the resilient attachment tabs 114 is operably connected to the load spreader 122, such that deflections and forces experienced by any one attachment tab 114 are distributed to other attachment tabs 114 via the load spreader 122.

Abstract: A bearing cage for a rolling element bearing assembly, the bearing cage including a cage body having an inner surface defining a bore coaxially aligned with the principal rotational axis of the bearing cage; a plurality of pockets, each pocket being suitable for housing a rolling element of the rolling element bearing assembly, the pockets being arranged sequentially around the cage body with respect to the principal rotational axis of the bearing cage; and a skirt projecting from the cage body in the axial direction; characterized by a flow deflector projecting from the skirt in the radial direction.

Abstract: A method of manufacturing a component comprising a hollow axisymmetric body formed of a cured composite material is provided. The method includes the step of positioning the constituents of the composite material in a mold corresponding to at least a portion of the hollow axisymmetric body. The composite material is cured into a composite part, and residual stresses are generated in the composite material during the curing by controlling the temperature of the constituents in the mold. When the composite part is released from the mold, relaxation of the residual stresses causes one or more regions of the composite part to deflect in the radial direction of the hollow axisymmetric body, the position of greatest radial deflection of each region having a radial deflection which is at least 0.1% of the greatest diameter of the hollow axisymmetric body.

Abstract: A bearing cage for a rolling element bearing assembly includes an outer surface, an inner surface defining a bore, and a plurality of pockets. Each pocket of the plurality of pockets is configured to house a rolling element of the rolling element bearing assembly. The plurality of pockets are arranged sequentially around the bearing cage with respect to an axis of the bore. A guide portion of the inner surface is tapered in an axial direction of the bore such that dimensions of the bore increase towards a central region of the bore, and the bearing cage further includes a plurality of conduits providing fluidic communication between the inner surface of the bearing cage and the outer surface of the bearing cage.

Abstract: A fastener (1) is provided for clamping a first component (25) to a second component (27). The fastener has at least one resiliently deformable snap-fit member (5) which, in use, is inserted from a first side of the components through a channel (29, 31) extending thereacross. The snap-fit (5) member has an abutment surface (7) which, on emerging from the channel (29, 31), enters into snap-fit engagement with an opposing second side of the components to prevent retraction of the snap-fit member (5). The fastener (1) further has a spring arrangement which presses on the first side of the components on the insertion of the snap-fit member (5) to apply a compressive clamping force across the components between the spring arrangement and the abutment surface (7).

Abstract: A sealing plate for sealing a gap between two primary sealing plates is provided. The sealing plate has a sealing portion and a connector portion, wherein the sealing portion has a width which is greater than a width of the connector portion. An apparatus for sealing a gap between two structural components of a turbine, the apparatus including a plurality of primary sealing components, and at least one sealing plate is also provided, as is a turbine having a plurality of structural components with a gap between said structural components, wherein the gap is sealed by a plurality of sealing components, the sealing components comprising a plurality of primary sealing components and at least one sealing plate.

Abstract: An electro-magnetic coupling system for transferring torque between a pair of coaxial spools of a gas turbine engine is provided. The system includes a first rotor rotatable with one of the spools, a second rotor rotatable with the other of the spools, and a stator. The first and second rotors and the stator are coaxial with each other. The second rotor operably couples the first rotor and the stator. The first rotor carries a plurality of magnetic flux-producing formations which produce a first magnetic field. The stator carries a plurality of electrical winding coils which are energisable to generate a second magnetic field. The second rotor carries an arrangement of interpoles which modulate the first and second magnetic fields such that the modulated fields interact to transfer torque between the spools.

Abstract: A method of balancing a physical rotor includes: determining a first balance state of the physical rotor at one or more rotational frequencies; identifying one or more balance zones on a surface of the rotor; providing a computerised simulation of the rotor having the first balance state; providing a first test mass in a first test location within one of the balance zones on the rotor simulation; determining a second balance state of the rotor simulation; providing at least one subsequent test mass in at least one subsequent test location within a balance zone on the rotor simulation and determining at least one subsequent balance state of the rotor simulation; selecting a mass and location from one of the first and subsequent test masses and test locations; and performing a material deposition process to add the selected mass of material to the selected location on the physical rotor.

Abstract: A component is treated in a fluidized bed by insertion of only a treatment part of the component into the treatment chamber of a fluidized bed apparatus. The non-treatment part of the component is located substantially outside the treatment chamber and out of contact with the fluidized bed. The boundary between the treatment part and the non-treatment part of the component is defined by a boundary containment surface at a fixed location with respect to the component. The boundary containment surface may be a seal which seals between the component to be treated and an aperture in a side wall of the treatment chamber.