Abstract: A control system comprises: a plurality of input devices; a plurality of remote output devices; a plurality of dedicated connections and a digital data network interconnecting the plurality of input devices and the plurality of remote output devices. Each one of the plurality of output devices is connected to one of the plurality of input devices by an associated one of the plurality of dedicated connections. Each output device is operable to detect an addressing error in the digital network by comparing a value of a parameter received via its dedicated connection with the value of the same parameter received via the digital data network. Each output device is operable to use a network address dependent upon a value received via its dedicated connection.

Abstract: A sensor apparatus including a plurality of sensors, and a measurement device. The plurality of sensors being divided into sensor groups with each sensor group having a number of sensors. The groups being arranged such that the sensor groups are electrically matched. The sensors in a sensor group coupled in parallel with each other to form a sensor ladder. A measurement device is arranged to compare electrical signals from each sensor group and to output an indication signal, wherein the measurement device is coupled to each sensor ladder at an intermediate position and in that the coupling position of each sensor ladder are electrically equivalent to one another. Also provided by the present invention is a method of monitoring a plurality of sensors.

Abstract: A magnetic valve arrangement for controlling flow of fluid, the magnetic valve arrangement having at least one ferromagnetic element (28, 42, 52) forming a portion of a magnetic circuit, a valve member (28, 50) and a valve seat (35); the valve member (28, 50) has a passage (31) therethrough for the flow of fluid and is moveable between a first position, in which the valve member (28, 50) abuts the valve seat (35) to restrict a fluid flow (26), and a second position, in which the valve member (28, 50) is spaced from the valve seat (35) to allow a fluid flow (26) into and through the passage (31) in the valve member (28, 50), wherein the position of the valve member (28, 50) is dependent on the temperature of the ferromagnetic element (28, 42, 52).

Abstract: A bearing arrangement comprising first and second components (2, 3) located for relative operational movement by a respective bearing (4), the bearing having a bearing element (5) comprising a pack of resiliently flexible bristles or leaves for transmitting force between the components thereby locally to provide a relative kinematic constraint on at least one degree of freedom of the components during said relative operational movement.

Abstract: A blade for a rotor, such as a turbine rotor of a gas turbine engine, has a squealer tip comprising a peripheral wall which defines a cavity. A first region of the peripheral wall extends radially, with its outer surface forming a continuation of the adjacent aerofoil surface of the blade. A second region extends obliquely with respect to the radial direction and the adjacent part of the aerofoil surface. The second region defines a winglet, and serves to increase the width of the chamber towards the trailing edge of the blade.

Abstract: It is known that overshoot in fuel flow rate as a result of compensating for engine heat soak effects can create transient over values in desired thrust parameters. These over values may be displayed and/or utilised in other engine control systems, and although transient may create problems within the engine and apprehension with a user. By adjusting the normally calculated fuel flow rate to a fuel regulator by the introduction of a fuel flow adjustment dependent upon a variable which is related to heat soak effects it is possible to reduce the extent of overshoot as well as the transient time period of that overshoot to ongoing operational state. The variable used may be direct or indirect and will generally utilise a temperature sensor within the engine and/or other engine control procedures which may be extrapolated from such sensor values to provide a variable for heat soak compensation.

Abstract: A power transmission arrangement comprises a first power transmission member connectable to a first main shaft of an engine. The arrangement also includes a second power transmission member connectable to a second main shaft of the engine and to a third power transmission member. A coupling assembly is provided which has a selectable coupling condition to couple the first power transmission member to the second power transmission member to allow power to be transmitted from the third power transmission member to the first main shaft of the engine via the first power transmission member. The coupling assembly has a decoupling condition to decouple the first power transmission member from the second power transmission member to allow power to be transmitted from the main shaft of the engine to the third power transmission member via the second power transmission member.

Abstract: A gas turbine engine having three shafts connecting respective high, intermediate and low-pressure turbines and compressors is characterised by an intermediate pressure turbine that includes two rotor stages.

Abstract: Magnetic gearboxes comprising an inner rotor and an outer rotor are known with pole members between them. However, these gearbox arrangements generally have a fixed gear ratio between the rotors. By provision of pole members with coils between them and associated switches to adjust the magnetic flux modulation capacity between the rotors it is possible to create open circuit, closed circuit and variable impedance configurations which will relatively passively adjust the magnetic flux modulation capacity or by presenting a voltage to the coils or drawing a voltage from the coils to more actively adjust the magnetic flux modulation capacity across the arrangement. In such circumstances a wider range of gear ratios is achieved as well as the capability with regard to localised electrical power generation through the gearbox arrangement or electro magnetic braking achieved upon the gear box as required.

Abstract: A hydraulic seal arrangement for a rotating machine, particularly a gas turbine engine, comprises a hydraulic seal and a hydraulic trap. When the machine is shut down, oil is retained in the hydraulic trap. When the machine is restarted, the oil from the hydraulic trap is available to re-make the hydraulic seal, thereby reducing or avoiding the leakage that typically occurs in such seal arrangements until the flow of oil through the seal arrangement is re-established.

Abstract: A vane for a gas turbine engine includes an aerofoil part and a shroud that forms a sealing part at one end of the aerofoil part. The sealing part defines a cavity and an opening to the cavity. The sealing part may include a pair of opposed side walls extending from a radially outer wall of the shroud to a pair of radially inner walls of the shroud to define a cavity. The pair of radially inner walls may be substantially parallel to the radially outer wall and may extend in a substantially circumferential direction to define a cavity opening.

Abstract: A stator vane assembly comprising inner and outer support rings connected by an annular array of stator vanes at locations around the supporting rings, at least one of said stator vanes in said array being a separate, pre-formed stator vane which is slidably connected to one or both of the supporting rings for radial movement relative to the respective support ring thereby to accommodate relative radial expansion of the support rings.

Abstract: Apparatus is provided comprising first and second coaxial shafts, the first and second shafts extending along, and being rotatable about, a central axis. The first and second shafts are coupled together by a splined major coupling at a coupling region of the apparatus, which major coupling enables the shafts to co-rotate about the central axis. A torque element is connected to the first and second shafts, the torque element being operable to force the first and second shafts to relatively rotate about the central axis in order to apply a preload to the major coupling. The apparatus may be comprised in a gas turbine engine, whereupon the first shaft may be a fan shaft and the second shaft may be a LP turbine shaft.

Abstract: An artificial bird projectile is provided for simulating bird strike events. The projectile has a solid foam phase and a gel or liquid phase. The gel or liquid phase is supported by the foam phase. The projectile may be suitable for simulating bird strike events on aero gas turbine engines.

Abstract: A forcing tool is provided in which a lobe aperture incorporates opposed lobe pairs having driving flanks. Distal ends of the driving flanks define a spacing consistent with the width of a dowel or tang to be utilized in a twisted-dowel joint. The aperture incorporates location recesses to allow the dowel or tang to pass through the aperture and then through twisting create a lock condition.

Abstract: An apparatus for determining a clearance between rotor blade tips of rotor blades mounted on a rotor and a stator lining mounted on a stator casing. The stator lining is movable radially relative to the stator casing. The stator lining comprises an abradable material. At least one probe is arranged to measure the clearance between blade tips and stator lining. A first portion of the at least one probe is arranged within the stator lining and a tip of the first portion of the at least one probe is arranged flush with the surface of the abradable material. The tip of the first portion of the at least one probe comprises an abradable material. A second portion of the at least one probe is secured to the stator casing. A wire-less and connector-less coupling transmits a measurement signal from the first portion to the second portion of the at least one probe to allow radial movement of the stator lining relative to the stator casing.

Abstract: An expander for concentrically expanding a cylindrical member, the expander with a tapered block, a plurality of segments, each having an inner surface at least partially in contact with the tapered surface of the tapered block and the segments arranged to move in concert with each other relative to the block, and a pair of engaging features being provided for each segment, each pair comprising a first engagement feature on one of the segments and a second engagement feature on the block, the pairs of engaging features being arranged to maintain equal circumferential spacing of the segments around the block and to constrain movement of the segments in a direction that is coaxial with the block, each pair of engaging features being located away from the circumferential edges of their respective segment.

Abstract: A flux-switching magnetic machine is provided having a drive element and a driven element. The drive element is configured to generate a composite magnetic field comprising a fixed component and a variable component, the fixed component being generated by spaced fixed field members and the variable component being generated by spaced armature windings. The driven element has a plurality of magnetisable portions configured to be coupled to the composite magnetic field generated by the drive element, such that the driven element moves in response to changes in this field. The number of fixed field members is greater than the number of armature windings.

Abstract: A gas turbine engine comprising an oil system and a gearbox, the gearbox is driven by at least one engine shaft, the oil system comprises a pump drivingly connected to the gearbox, an oil tank connected to the pump via a supply pipe and a delivery pipe connecting the pump to the engine for delivery of oil thereto, an anti-siphon pipe is connected between the tank and the delivery pipe to provide an excess oil flow to the engine characterized in that the anti-siphon pipe includes a variable flow valve for regulating the flow of oil passing therethrough such that at low engine speeds an adequate supply of oil is provided to a sight glass in the tank.

Abstract: A method of controlling blade pitch angle, comprising the steps of: comparing demanded and measured blade pitch angle and calculating any difference therebetween, in a primary electrical control system, where there is a difference, applying torque to a blade pitch regulator to reduce the magnitude of the difference to zero, and in a secondary electrical control system, where the difference is greater than a pre-determined threshold, applying torque to a blade pitch regulator to reduce the magnitude of the difference to the threshold. Also an electrical system of blade pitch angle control for a set of blades comprising: primary and secondary electrical control systems, means for comparing demanded and measured blade pitch angle and calculating any difference therebetween, a look-up function having the difference as its input and outputting a required torque, and a torque regulator to apply the required torque to the set of blades.