Abstract: A method and apparatus for rigging a variable stator vane arrangement (100) for a gas turbine engine (10) is provided. The arrangement provides at least two sets of rigging holes to an actuator (200), with the actuator extension during rigging being dependent on which of the sets of holes are aligned. This allows the actuator extension to be adjustable during rigging, thereby facilitating different relationships between actuator extension and variable vane angle in use.

Abstract: A gas turbine engine is disclosed including a bifurcation fairing located in a bypass duct of the gas turbine engine and traversing the radial extent of the bypass duct. The bifurcation fairing has a delivery conduit inlet leading to a delivery conduit extending inside the bifurcation fairing, the delivery conduit being arranged in use for delivery of bypass air to one or more components of the gas turbine engine. A diverter conduit has a diverter conduit inlet from the delivery conduit upstream of the delivery conduit reaching the one or more components of the gas turbine engine. The diverter conduit has an outlet to a location other than the one or more components of the gas turbine engine.

Abstract: An example system includes at least one acoustic sensor configured to generate at least one acoustic data signal indicative of an acoustic signal generated by a thermal spray system comprising a flowstream, a computing device, and an acoustic data signal processing module operable by the computing device to determine an ignition attribute of the thermal spray system by analyzing at least a pre-ignition window of the acoustic data signal received by the computing device.

Abstract: A roller assembly for a rotary dresser comprise a plurality of axial segments which may be in the form of discs, each disc provided with an abrasive, radially outer surface. The discs are secured in axial alignment, each in a preconfigured rotational orientation. The disc assembly has a centrally arranged aperture for receiving a rotor shaft. The abrasive surface of the assembly can be accurately presented as an array of uniformly shaped abrasive units in a predefined pattern.

Abstract: A method linear friction welds a rotor blade to a disk. The method includes: providing a linear friction welding machine having disk tooling at which a disk is mounted, and further having blade tooling at which a blade is mountable; mounting a dummy blade at blade tooling, dummy blade carrying one or more first measurement devices which interact with mounted disk to measure position of dummy blade relative to disk; adjusting position and orientation of blade tooling relative to mounted disk until first measurement devices indicate that dummy blade is in a suitable alignment with disk to start linear friction welding a blade to disk; releasing dummy blade from blade tooling and mounting a production blade thereat; and linear friction welding the production blade to the disk with the blade tooling starting at adjusted position and orientation.

Abstract: An attrition liner machining tool, configured to machine the surface of an attrition liner provided radially outward of a set of a plurality of fan blades in a gas turbine engine. The tool includes at least one rotating machine tool having a connector at a first end and a cutter at a second end. The connector is configured to rigidly connect to a rotating fan blade mount of the gas turbine engine that, in use of the gas turbine engine, supports the fan blades. The cutter is configured to machine the attrition liner. The at least one rotating machine tool is configured such that, when it is connected to said rotating fan blade mount of a gas turbine engine, the cutter is passed across the surface of the attrition liner when said rotating fan blade mount is rotated.

Abstract: A bearing arrangement comprising a shaft with a recess in its end, a bearing housing, an annular first bush comprising an inner first portion and an inner second portion and a second bush that engages the recess of the shaft. The first bush bears against the bearing housing. The shaft engages the inner first portion of the first bush. The second bush engages the inner second portion of the first bush.

Abstract: An energy source for an additive manufacturing arrangement comprises a workpiece and a powder delivery device. The energy source is characterised in that it comprises a plurality of discrete energy sources. The plurality of discrete energy sources may be coordinated in use to deliver energy simultaneously to a plurality of regions of the workpiece in a matrix form.

Abstract: A method of: (i) providing a mould, comprising a mould body and a mould cavity; (ii) positioning the workpiece within the mould cavity; (iii) providing a plurality of part locator rods, each rod being located in the mould body and protruding into the mould cavity, a distal end of each rod abutting against an outer surface of the workpiece; (iv) providing a fluid, the fluid filling a void defined between an outer surface of the workpiece and an internal surface of the mould cavity; (v) cooling the mould, workpiece and fluid to below a freezing point of the fluid; (vi) removing the workpiece encapsulated in frozen fluid, from the cavity, with the rods protruding from outer surface of frozen fluid; (vii) securing the encapsulated workpiece on a machine tool; and (viii) using the protruding part locator rods to position the workpiece on the machine tool in readiness for machining operation.

Abstract: A rotor is provided comprising a centre of mass and a rotational axis and a rotor sealing component extending circumferentially around the rotor for sealing between the rotor and a stator, wherein the centre of mass of the rotor is coincident with the rotational axis, and material of the rotor sealing component is not evenly distributed around its circumference. A stator sealing component in which the material is not evenly distributed around its circumference is also provided.

Abstract: Stator vane assembly includes plurality of vanes arranged in circumferential array, radially proximal mounting portion, radially distal mounting portion, and first latching mechanism. Each of plurality of vanes extends radially between radially proximal mounting portion and radially distal mounting portion, with each of plurality of vanes being pivotally mounted between radially proximal mounting portion and radially distal mounting portion. Plurality of vanes is movable between first arrangement allowing gas to flow across vanes, and second arrangement blocking gas flow across vanes. Pivot axis of each of plurality of vanes is offset from the line of aerodynamic center of pressure of vane towards trailing edge of vane, and first latching mechanism holds plurality of vanes in first arrangement. Upon receipt of signal, first latching mechanism releases plurality of vanes so that gas flow through vane assembly causes plurality of vanes to move from first arrangement to second arrangement.

Abstract: A fluid transfer coupling includes a first and second shaft assembly. The first shaft assembly includes a shaft and annular fin attached to shaft, annular fin having one or more internal passages extending therethrough. The or each internal passage connects a center portion of shaft to a radially outwardly facing side of annular fin. The second shaft assembly includes a shaft and annular trough extending radially outwardly of shaft. The first shaft is concentrically accommodated within second shaft with annular fin being accommodated within annular trough. In use, first shaft assembly rotates at a first rotational speed and second shaft assembly rotates at a second rotational speed, with second rotational speed being greater than first rotational speed. The difference between second and first rotational speeds cause a fluid contained within annular trough to be driven radially inwardly through the or each internal passage to center portion of first shaft.

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 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: An electrical machine has a variable reluctance rotor, and a stator formed as an annular array of stator segments. The reluctance of the rotor-to-stator magnetic flux path varies with rotor position whereby the stator segments are magnetically energizable to rotate the rotor. The stator segments are arranged in the array such that, when energized to rotate the rotor, they produce an unbalanced force on the rotor. The machine further has a compensator including one or more balancing segments which are configured to be magnetically energizable to produce a balancing force on the rotor which balances the unbalanced force. The reluctance of the rotor-to-compensator magnetic flux path is substantially invariant with rotor position.

Abstract: A gear pump bearing block has a bush formed of antifriction alloys. The bush has a cylindrical portion providing a bore adapted to receive a bearing shaft of a gear of the pump. It further has a thrust face at the end of the cylindrical portion, the thrust face being adapted to slidingly engage with a side surface of the gear. The bush has an inner component providing the bore, and an outer component forming a radially outer surface of the cylindrical portion. The inner and outer components are formed of respective lead bronze alloys, the lead bronze alloy of the outer component having a higher lead content than the lead bronze alloy of the inner component.

Abstract: A fuel spray nozzle, for atomising liquid fuel in gas, including: an gas passage; a liquid fuel passage; a swirler provided in the gas passage and including vanes such that, when gas passes through the gas passage, the swirler produces a jet flow of gas from between adjacent vanes and a turbulent flow of gas in the wake of each vane; a prefilming surface for receiving liquid fuel from the liquid fuel passage, and gas from the gas passage, wherein the prefilming surface includes areas that receive jet flow of gas from the gas passage, in use; wherein the fuel spray nozzle is configured to direct the liquid fuel passing through the liquid fuel passage to the areas on the prefilming surface that receive a jet flow of gas from the gas passage.

Abstract: An auxiliary oil supply apparatus for a rotating device (50, 51), the rotating device comprising a primary oil supply (52), a rotating component (50) and a static component (51) situated radially outwardly of a centre of rotation of the rotating component (50) and arranged to collect oil (58) held radially outwardly from the rotating component (50) as the rotating component rotates. The auxiliary oil apparatus comprises a scoop (56) associated with the rotating component (50) and is responsive to a change in a known parameter to move between a first position in the static component (51) to a second position between the static component (51) and the centre of rotation.

Abstract: There is disclosed an aero gas turbine engine comprising a compressor and an array of variable inlet guide vanes for the compressor. The angle of the variable inlet guide vanes is controlled by scheduling, the scheduling comprising a first component invoked for engine ground start and a second component invoked for engine in-flight windmill start at least under particular flight conditions. The angle of the variable inlet guide vanes required by at least a portion of the second component is greater than the angle of the variable inlet guide vanes required by at least a portion of the first component.

Abstract: A seal arrangement for effecting a seal between first and second components arranged for relative rotation about a common axis. Seal arrangement includes a first seal surface associated with the first component, and a second seal surface associated with the second component. First and second seal surfaces are presented for air-riding interaction with one another during relative rotation between components such that, in use, a pressure drop is maintained across seal arrangement. First seal surface incorporates a plurality of spaced-apart hydrodynamic lift-generating features and plurality of ventilation recesses, each ventilation recess being interposed between respective pair of lift-generating features, and wherein each ventilation recess has depth measured normal to first seal surface which is greater than maximum dimension of each lift-generating feature measured normal to first seal surface. Seal arrangement may be embodied in compliant filament seal such as a leaf seal or a brush seal.