Abstract: A method of bonding a first article to a second article, each article having a respective bond surface. The method comprises interposing a porous interlayer region between the bond surfaces of the first and second articles and subsequently using electrical resistance heating to locally heat the interlayer region under contact pressure to a bonding temperature below the melting temperature of the interlayer and the first and second articles to thereby bond the interlayer to the first and second articles to form a bonded article. The interlayer has a porosity of between approximately 10% and 30%.

Abstract: A thrust balancing mechanism for balancing axial loads on a rotor thrust bearing 3 is described. The mechanism comprises a piston arrangement 6 axially mounted on a stationary structure 2, about a centre axis arranged, in use, in coaxial alignment with a rotating shaft 1 carrying the rotor thrust bearing 3. A hydrodynamic thrust bearing 8 is mounted, in use, between the piston 6 and the rotor thrust bearing 3. The piston 6 is pressurised so as to impart to the rotor thrust bearing 3, via the hydrodynamic thrust bearing 8, an axial load which counters an axial load imparted to the rotor thrust bearing 3 by the rotating shaft 1.

Abstract: A fluid system comprising a surface that is fluid washed in use by a fluid flow travelling substantially parallel to the surface is disclosed. The system has a first port through the surface and a second port through the surface, the first and second ports having respective first and second port inlets that are substantially flush with the fluid washed surface. The first and second port inlets are stacked in a direction parallel to the normal flow of fluid over the fluid washed surface such that the first port is upstream of the second port and fluid travelling closer to the fluid-washed surface entering into the first port tends to entrain fluid travelling further from the fluid-washed surface for entry into the second port.

Abstract: An apparatus for manufacturing an article from powder material includes a canister, a sorter, a plurality of hoppers and at least one valve. The canister has a predetermined internal shape to define the shape of the powder metal article. The sorter sorts the powder material by the size of the powder particles, the shape of the powder particles and/or the flow characteristics of the powder particles. The hoppers contain powder material with different sizes of powder particles, different shapes of powder particles and/or powder particles with different flow characteristics. The hoppers are arranged to supply the sorted powder material to the canister. The at least one valve controls the proportions of the different powder materials supplied from the one or more of the different hoppers into the canister to control the packing density of the powder material in the canister at all positions in the canister.

Abstract: A doctor device (10, 11) configured for use in recoating in an operating additive layer manufacturing apparatus is configured, in use, to flex on a first sweep across a surface (8a) and remain stiff relative to the flexibility exhibited in the first sweep during a second sweep of the surface.

Abstract: A gas turbine engine 10 comprises at least one rigid raft assembly that has a fluid passageway 210 at least partially embedded therein. The fluid passageway 210 is at least a part of a fluid system. In addition to the fluid passageway 210, the rigid raft assembly 200 also has at least a part of another system. For example, the rigid raft assembly may also include electrical conductors 252, which are part of an electrical system. The rigid raft assembly 200 may be lighter, easier to assemble, more robust and more compact than conventional solutions for providing systems to gas turbine engines.

Abstract: The invention concerns an asset monitoring system (10) having a monitoring unit 8 and a plurality of sensors (4) onboard the asset. The sensors (4) are arranged to measure a plurality of operational variables for the asset in use and the monitoring unit (8) is arranged to receive operational variable measurements output from the sensors. The monitoring unit is also arranged to determine a current value of a sensor characteristic (ZA1; ZB1) for each sensor and to compare the current sensor characteristic value with a predetermined sensor characteristic value in order to determine automatically whether a change of one or more sensors has occurred between instances of operation.

Abstract: An aircraft electrical power generation system includes an AC generator having a rotor including a plurality of electromagnetic rotor-windings and stator including plurality of electrical stator-windings. The rotor mechanically coupled to a shaft of a gas turbine engine by transmission-system. The generator includes a frequency controller, a torque sensor determining a torque on the transmission-system by the generator and controller to operate the system in first and second modes. In first mode, the power output frequency of the generator controlled by the frequency controller within limits, and reduced idle signal going to a turbine engine controller. In second mode, the power output frequency of the generator not controlled by the frequency controller and increased idle signal going to the turbine engine controller. The controller operates the system in first mode when the torque is below a limit, and in second mode when the torque is above a limit.

Abstract: A flow deflector arrangement is used in combination with a pipe arrangement secured through a component, the flow deflector arrangement comprising: a nut to secure the pipe arrangement to the component, and a shroud for attachment to the component so as to extend at least partially around the pipe arrangement when the pipe arrangement is secured to the component by the nut. The nut has an outwardly directed flange to adopt a position spaced from the component, and the shroud defines at least one deflector surface which, when the shroud is attached to the component, extends away from the component in spaced relation to the pipe arrangement. The flange and the deflector surface cooperate in deflecting a flow of fluid flowing from the component and along the outside of the pipe arrangement such that the flow is deflected generally outwardly from the pipe arrangement with a degree of swirl.

Abstract: An electrical raft 200 comprising electrical conductors 252 embedded in a rigid material are provided to a gas turbine engine. The raft 200 is used to transport electrical signals (which may be, for example power and/or control signals) around a gas turbine engine. The electrical raft 200 has an electrical connector 700 embedded therein which is used to connect the electrical raft to an electrical unit, such as an EEC of a gas turbine engine The electrical connector 700 is resiliently biased so as to ensure a reliable electrical connection.

Abstract: A gas turbine engine includes a compressor assembly that is rotationally coupled to a shaft. The engine includes a radial diffuser assembly coupled to a shroud of the compressor assembly and positioned to receive compressed air from a centrifugal impeller. The radial diffuser assembly includes a first arcuate wall and a second wall, and a near axial diffuser coupled to the radial diffuser assembly and positioned to receive the compressed air from the radial diffuser assembly. The gas turbine includes a gas seal coupled between the second wall and a wall of the near axial diffuser, the gas seal configured to prevent the compressed air from passing through the seal while allowing relative motion between the radial diffuser assembly and the near axial diffuser.

Abstract: The present disclosure provides a clipping tool for clipping flash from a component e.g. a gas turbine aerofoil body. The clipping tool includes a riser having a support surface for supporting the component and a punch for gripping the component on the support surface such that the flash projects laterally from the riser and the punch. The clipping tool further comprises a tool body having a clipping aperture opening to a channel within the tool body. The channel is defined by a channel wall. The riser and the punch are translatable to shear the projecting flash from the gripped component. At least a portion of the channel wall within the tool body comprises a broaching surface having at least one projection, said projection reducing the cross sectional area of the channel to less than that of the clipping aperture.

Abstract: A gas turbine engine fuel system (100) comprises: a combustor (20) comprising at least one fuel injector (106), a fuel manifold (104) configured to supply fuel to each injector (106) and a drain tank (108) in fluid communication with the fuel manifold (104). Each fuel injector (106) comprises a first check valve (132) configured to allow one-way flow from the manifold (104) to the fuel injector (106), and a second check valve (134) configured to allow one-way flow from the fuel injector (106) to the fuel manifold (104). The system (100) further comprises a vacuum generator (112) configured to selectively provide below atmospheric pressure to the drain tank (108).

Abstract: An actuation system is provided for varying the pitch of the blades of a variable pitch fan or propeller. The actuation system includes a first actuator and a second actuator. The actuation system further includes a first linkage which operably connects the first actuator to the blades such that operation of the first actuator varies the pitch of the blades via the first linkage. The actuation system further includes a second linkage which operably connects the second actuator to the first actuator such that operation of the second actuator varies the pitch of the blades by series connection of the second linkage to the first linkage.

Abstract: A bearing arrangement comprising: a first bearing including a first inner race coupled to a rotatable component, a first outer race; and a plurality of first roller elements between the first inner race and the first outer race; a second bearing including a second inner race coupled to the rotatable component, a second outer race, and a plurality of second roller elements between the second inner race and the second outer race; a component, the first outer race being axially moveable relative to the component; and a member between the first bearing and the second bearing and arranged to provide an indirect first force on the first outer race to prevent the first roller elements from skidding when the first bearing and the second bearing receive a second force in a first direction, the second bearing being configured to transfer the second force to the component.

Abstract: An apparatus for the simultaneous casting of multiple components using a directional solidification process includes; a pouring cup arranged on a centreline, an array of moulds encircling the pouring cup and centre line, an array of feed channels extending from the pouring cup to a top end of each mould, and a heat deflector. The heat deflector comprises a wall arranged between the array of moulds and the centreline extending along the length of the moulds and in thermal contact with the moulds.

Abstract: A stainless steel alloy including essentially of 19 to 22 percent by weight chromium, 8.5 to 10.5 percent by weight nickel, 5.25 to 5.75 percent by weight silicon, 0.25 to 1.2 percent by weight carbon, 4.0 to 6.0 percent by weight niobium, 0.3 to 0.5 percent by weight titanium and the balance iron plus impurities. The impurities may include 0 to 0.2 percent by weight cobalt, 0 to 0.5 percent by weight manganese, 0 to 0.3 percent by weight molybdenum, 0 to 0.03 percent by weight phosphor, 0 to 0.03 percent by weight sulphur, 0 to 0.1 percent by weight nitrogen.

Abstract: A stainless steel alloy comprising essentially of 19 to 22 percent by weight chromium, 8.5 to 10.5 percent by weight nickel, 5.25 to 5.75 percent by weight silicon, 0.25 to 2.0 percent by weight carbon, 4.0 to 10.5 percent by weight molybdenum, 0.3 to 0.5 percent by weight titanium, 0.1 to 0.5 by weight percent nitrogen and the balance iron plus impurities. The impurities may consist of 0 to 0.2 percent by weight cobalt, 0 to 0.5 percent by weight manganese, 0 to 0.3 percent by weight molybdenum, 0 to 0.03 percent by weight phosphor, 0 to 0.03 percent by weight sulphur, 0 to 0.1 percent by weight nitrogen.

Abstract: A gas turbine engine is provided that has a rigid dressing raft mounted to a rigid part of the gas turbine engine. The rigid dressing raft includes at least a part of a component or system of the gas turbine engine. For example, the rigid dressing raft may have electrical conductors embedded therein that are a part of the electrical system of the gas turbine engine.

Abstract: A method of inspecting the fan track liner of a gas turbine engine of a type having a rotatable propulsive fan circumscribed by a fan track liner and having a plurality of fan blades extending radially outwardly from a central hub. The method comprises the steps of: affixing at least part of an inspecting device to the fan so as to be directed towards the fan track liner; and rotating the fan within the fan track liner to move the at least part of the inspecting device circumferentially relative to at least a region of the fan track liner to thereby scan the region of the fan track liner with the at least part of the inspecting device.