Abstract: A rolling-element bearing 1 comprising an inner race 3, an outer race 2 and an array of rolling elements 4 arranged within a bearing cage 5 situated between the two races 2, 3, the inner surface of the bearing cage 5 being piloted on the inner race 3 for limiting eccentric movement of the cage 5 within the bearing 1 and further having a reservoir 9 formed between a pair of circumferential weirs 6a, 7b on the cage 5, the outer surface of the inner race 3 comprising a raised land portion 3d for contacting oil 9a in the reservoir 9 thereby to control the relative speed of the cage 5 and the inner race 3, wherein the radial depth of each weir 6b, 7b is greater than the maximum radial clearance between the land portion 3d and the cage 5 for maintaining said controlling contact between the land portion 3d and the oil 9a during said eccentric movement of the cage 5.

Abstract: A method of securing a releasable component in an assembled engine by inserting a conduit through an aperture in a casing of the engine, the conduit being carried by a borescope and directing the borescope to the releasable component, and supplying an adhesive onto the releasable component through the conduit.

Abstract: Within aerofoils, and in particular nozzle guide vane aerofoils in gas turbine engines problems can occur with regard to coolant flows from respective inlets at opposite ends of a cavity within the aerofoil. The cavity generally defines a hollow core and unless care is taken coolant flow can pass directly across the internal cavity. Previously baffle plates were inserted within the cavity to prevent such direct jetting across the cavity. Such baffle plates are subject to additional costs as well as potential unreliability problems. Baffles formed integrally with a wall within the aerofoil allow more reliability with regard to positioning as well as consistency of performance. The baffles can be perpendicular, upward or downwardly orientated or have a compound angle.

Abstract: Within aerofoils (50, 150, 250, 350), and in particular nozzle guide vane aerofoils in gas turbine engines problems can occur with regard to coolant flows (56, 57; 156, 157; 256, 257; 356, 357) from respective inlets at opposite ends of a cavity (60, 160, 260, 360) within the aerofoil (50, 150, 250, 350). The cavity (60, 160, 260, 360) generally defines a hollow core and unless care is taken coolant flow can pass directly across the internal cavity. Previously baffle plates were inserted within the cavity to prevent such direct jetting across the cavity. Such baffle plates are subject to additional costs as well as potential unreliability problems. Baffles (55, 155, 255, 355) formed integrally with a wall (54, 154, 254, 35) within the aerofoil (50, 150, 250, 350) allow more reliability with regard to positioning as well as consistency of performance. The baffles (55, 155, 255, 355) can be perpendicular, upward or downwardly orientated or have a compound angle.

Abstract: An engine (110, 210) for moving a conveyance (132) through a fluid includes first and second pressure creating means (13, 14) for pressurising an engine airflow, and intercooling means (116, 290, 292) for cooling the engine airflow between the first and second pressure creating means (13, 14). The intercooling means (116, 290, 292) includes a heat exchanger (116) which is arranged to be cooled by a flow of the fluid generated by the relative movement of the conveyance (132) through the fluid.

Abstract: A gas turbine engine simulator comprising a simulator rotor disc which has substantially the same maximum external dimensions as a rotor disc and is manufactured from a material which has a density of less than 220 kg/m3. The simulator rotor disc is manufactured from a foamed plastic material with a closed cell structure. The simulator rotor disc is provided with a cavity in flow communication with a source of simulator coolant fluid, at least one flow outlet, at least one heater unit and at least one thermocouple mounted within said cavity for the measurement of simulator coolant fluid temperature within said cavity.

Abstract: A load absorption arrangement 40 for absorbing loads in a variable stator vane positioning system of a gas turbine engine includes a valve 42 which has a first operating condition to enable the load absorption arrangement 40 to transmit load, and a second operating condition, which is operable above a predetermined load, in which the valve 42 can release to enable the load absorption arrangement 40 to absorb the load thereon. The arrangement 40 is particularly suitable for absorbing shock loads which may arise under engine surge.

Abstract: A substrate (33) is clamped into a fixture (32) and material is deposited thereon to form a complex article (40). The article (40) produced is packed, using ceramic inserts (42) and a coating (41). The packing (42) ensures that the article (40) maintains its true shape and allows for expansion during the subsequent heat treatment process. The packed article (40), mounted on the fixture (32), is then placed in a box (44), encased in a granular material (43) and heated. It is heated to a temperature sufficient to relieve stresses and is maintained at this temperature for a time period such that the stresses in the article (40) are relieved.

Abstract: A forming apparatus (20) and method are provided for forming an item (10). The item includes an end part (12), a body part (14) and a tip (16), the body part extending from the end part, the tip being located at an end of the body part remote from the end part. The invention is characterised in that the apparatus includes a tip holder (22) for holding the tip and an end die (26) for clamping the end part; a rotator (42) for inducing relative rotation between the end die and the tip holder which, in a twisting step, induces a twist in the body part in use; and a body die (32), the body die including one or more formation surfaces (34), the body die being arranged in use in a conformation step to conform one or more surfaces (50) of the twisted body part to the or each formation surface.

Abstract: A fuel injector for a fuel spray nozzle of a gas turbine engine combustor is provided. The fuel injector has an annular flow passage which conveys fuel to a prefilming lip at an end of the flow passage. The fuel injector also has plurality of fuel distributor slots which are circumferentially spaced around and in fluid communication with the other end of the flow passage to deliver respective fuel streams into the flow passage. The slots are configured so that the fuel streams enter the flow passage at a swirl angle of at least 80° relative to the axis of the flow passage.

Abstract: A noise reduction device 40, for example for use in a bleed assembly 30 of a gas turbine engine, comprises partitions 50, 52 forming cells 54 having apertures 56, 58, 60 which provide contractions and sudden expansions of flow passing through the device. The apertures 56, 58, 60 are disposed relative to each other so as to force the flow to change direction within the cells 54 to break up jets of gas issuing from the apertures 56, 58, 60. Webs 62, 64, 66 may be provided adjacent the apertures 56, 58, 60 to direct flow and to assist in generating turbulence.

Abstract: Within components such as high pressure turbine blades and aerofoils in a gas turbine engine it is important to provide cooling such that these components remain within acceptable operational parameters. Typically, film cooling as well as convective cooling is utilised. Film cooling requires holes from a feed passage from which the coolant is presented upon an external surface to develop the film. The holes themselves can create cooling through convective cooling effects. In order to maximise the convective cooling effect holes are created which have an indirect path about a direct line between an inlet and an outlet for the hole. By creating an indirect path in the form of a helix or spiral which in turn may have a variable cross sectional area from the inlet to the outlet control of coolant flow can be achieved.

Abstract: A noise reduction device 40, for example for use in a bleed assembly 30 of a gas turbine engine, comprises partitions 52, 56, 60 having apertures 64, 66, 68 which provide contractions and sudden expansions of flow passing through the device, turbulators 62 being provided between the partitions 52, 56, 60 to break up jets issuing from the apertures 64, 66, 68. Breaking up the jets before impact with the partitions 52, 56, 60 enables the partitions to be disposed closer together, so enabling adequate noise reduction to be achieved in a device of relatively small thickness.

Abstract: A synchronous electrical machine comprising a plurality of phases, detecting means arranged to detect a fault in at least one of the phases of the synchronous electrical machine, isolating means arranged to isolate the at least one phase of the synchronous electrical machine with the fault, phase shift means arranged to produce a controlled phase shift between the voltage and the current within the remaining phases of the synchronous electrical machine to adjust the phase angle and magnitude of the second harmonic powers produced by the remaining phases of the synchronous electrical machine such that the vector sum of the second harmonic power vectors of the remaining phases of the synchronous electrical machine is zero.

Abstract: A flow control system comprises includes a fluidic control device having a main fluid path for a flow of fluid through the device, and a control fluid path for a control flow of fluid through the device. At least part of the control fluid path coincides with at least part of the main fluid path to control the flow of fluid out of the fluidic control device. A valve is associated with the control fluid path. The valve is movable between an open condition to allow fluid to flow along the control fluid path to effect the aforesaid control of the fluid flow out of the fluidic control device, and a closed condition to inhibit or prevent fluid flow along the control fluid path.

Abstract: A turbofan gas turbine engine (10) comprises a variable area exhaust nozzle (12) arranged at the downstream end of a casing (17). A control unit (66) analyses the power produced by the gas turbine engine (10), the flight speed of the gas turbine engine (1) and/or the altitude of the gas turbine engine (10). The control unit (66) configures the variable area nozzle (12) at a first cross-sectional area (70A) when the flight speed of the gas turbine engine (10) is less than a first predetermined value. The control unit (66) configures the variable area nozzle (12) at a second, smaller, cross-sectional area (70B) when the flight speed of the gas turbine engine (10) is greater than the first predetermined value and the power produced by the gas turbine engine (10) is greater than a second predetermined value.

Abstract: Components such as turbine shafts 2, 4 are maintained coaxial with each other by a coupling ring 6. The coupling ring 6 comprises a body 12 which is cylindrical when unstressed, and which has two arrays of projections 14, 16, each array engaging a respective cylindrical surface 24, 26 of recesses 8, 10 in the components 2, 4. The body 12 is flexible, and so is resiliently deformed by contact between the projections 14, 16 and the respective cylindrical surface 24. The projections 14, 16 of the two arrays are angularly out of phase with each other.

Abstract: There is a requirement to provide bearings in relatively low speed non continuous situations such as with regards to turnover stands for engine and winding assembly. Previous bearings incorporating rolling elements are relatively expensive and over specified for such activities. By providing annulus members in a bearing cluster upon rocker members such that the annulus members can articulate in order to provide an appropriate bearing. Lubricating oil generally passes between the annulus members in a laminar stack such that the members can radially slide past each other to accommodate for eccentricities in a shaft supported by the bearing.

Abstract: A weld enclosure (15) and welding apparatus (10) including a weld enclosure (15). Also a method of welding. The apparatus (10) has first (12) and second (14) opposed tooling faces adapted to receive and hold respective first (16) and second (18) weld elements. The weld enclosure (15) comprises a housing (22, 24a, 24b) that allows relative movement between the weld elements (16, 18) and a change in a physical dimension of at least one of the weld elements (16, 18). The weld enclosure (15) also comprises locating means for locating the housing (22, 24a, 24b) relative to the welding apparatus and includes heating means (20).

Abstract: A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % tantalum and the balance titanium plus incidental impurities has an alpha transus temperature T? between 1310° C. and 1320° C. The gamma titanium aluminide alloy was heated to a temperature T1=1330° C. and was held at T1=1330° C. for 1 hour or longer. The gamma titanium aluminide alloy was air cooled to ambient temperature to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T2=1250° C. to 1290° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix. The heat treatment reduces quenching stresses and allows larger castings to be grain refined.