Abstract: An electro-mechanical fuse integrated into the enclosure of a bearing assembly of a generator or like component. Under normal operation, the electro-mechanical fuse provides continuity through a bearing sensing circuit. However, ball cage damage causes the fuse to open and, in turn, the bearing sensing circuit indicates bearing wear. Thus, damage to other generator components is greatly reduced because the generator is removed for maintenance in a timely manner.

Abstract: A drive disconnect device for releasably connecting an electrical generator to a drive shaft, the drive disconnect device comprising an output shaft and at least one drive transfer element movable from a first position where it drivingly connects the drive shaft and the output shaft to a second position where the driving connection is removed, wherein operation of the disconnect device causes the electrical generator to become electrically isolated or excitation for the generator to be inhibited.

Abstract: A rotary electric machine comprises a rotor rotatable within a stator assembly, the stator assembly comprising a stator body defining a plurality of stator slots accommodating electrical conductors, a slot liner being provided within each slot to provide electrical insulation between the stator body and the electrical conductors, wherein each slot liner protrudes from an end of the stator slot and carries an armour element to protect the slot liner and associated conductors from erosion whilst permitting efficient cooling.

Abstract: A fuel pumping system comprises a high pressure pump having a drive input, a drive gear driven for rotation, in use, by the drive input, an idler gear driven by the drive gear, and an output gear driven by the idler gear, wherein the output gear is arranged to drive a rotor of an electrical generator and the idler gear is arranged to drive a rotor of a low pressure pump.

Abstract: A motor comprising a motor housing, a stator located within the motor housing, a rotor supported for rotation within the motor housing upon a rotor shaft, the rotor shaft being supported for rotation by bearings, and a sealing sleeve, wherein the sealing sleeve is of closed ended form and encircles the rotor, the sealing sleeve being sealed adjacent its open end to the motor housing.

Abstract: A fuel system comprises a pressure raising valve operable to control communication between a fuel delivery line and an engine manifold line, and an ecology valve comprising a piston movable within a bore, the piston and bore together defining a control chamber and an ecology chamber, the ecology chamber communicating with the engine manifold line, the pressure within the control chamber being controllable to control the position occupied by the piston, the ecology valve further comprising seal means whereby, when the piston occupies a first position in which it engages the seal means, only a first, relatively small, effective area of the piston is exposed to a fuel pressure within the engine manifold line, a second, larger, effective area being exposed to the fuel pressure within the engine manifold line when the piston occupies a position in which it does not engage the seal. An ecology valve for use in the fuel system is also described.

Abstract: A rotor assembly comprises a rotor body defining a pole, a winding encircling the pole, a compression member located radially inwards of the winding, and compression means located between the compression member and the rotor body and operable to urge the compression member in an outward direction to apply a compressive load to the winding. A method of assembly of the rotor is also disclosed.

Abstract: A piezoelectric perovskite mixed oxide compound has the general formula (BiFeO3)x—(PbTiO3)1-x and contains up to 5 at % lanthanum or other rare earth substitution, in which x has a value in the range 0.5 to 0.9. Such compounds are capable of withstanding gas turbine operating temperatures and are suitable for use in sensing and actuation functions in aerospace and other applications.

Abstract: A fuel control system for a gas turbine engine reheat system has a plurality of fuel metering devices for controlling fuel flow to respective ones of the reheat burners, and a plurality of throttle valves in series with the respective metering devices. One of the throttle valves regulates a pressure difference across its associated metering device and the remaining throttle valves maintain the pressure difference across their respective metering devices equal to that controlled by the aforesaid one throttle valve. The system may include a fuel supply valve which is responsive to a pressure signal controlled by two of the metering devices so that fuel supply from a pump is provided only when both of the two metering devices are open. The pump may include a delivery pressure regulating arrangement responsive to pump delivery pressure and to the highest of the pressures downstream of the metering devices, for regulating pump delivery pressure so as to maintain the metering pressure differences constant.

Abstract: A method is described for controlling the operation of a metering valve driven by a stepper motor, a position sensor normally providing position information to allow control over the metering valve in a closed loop manner. The method comprises the steps of: performing a calibration operation to derive a relationship between stepper motor position and metering valve position; controlling the operation of the metering valve in a closed loop manner; and controlling the operation of the metering valve in an open loop manner in the event that the position sensor output is thought to be unreliable; wherein, when operating in the open loop manner, the metering valve is moved to a desired angular position by using the relationship derived in the calibration operation to determine the stepper motor position associated with the desired metering valve position and moving the stepper motor to the determined stepper motor position.

Abstract: A rotary metering valve arrangement comprises a rotary metering valve arranged to control the supply of fuel to a Pressure Raising and Shut-Off Valve (PRSOV), the metering valve comprising a valve plate provided with first and second latching ports and an angularly movable valve element provided with a recess registrable, in use, with the first and second latching ports to control communication therebetween, the PRSOV comprising a valve member slidable within a bore provided with third and fourth latching ports the valve member being provided with a recess registrable, in use, with the third and fourth latching ports to control communication therebetween, the second and third latching ports communicating with one another.

Abstract: A fuel system is described that comprises a pressure raising and shut-off valve (PRSOV), and a control valve arrangement operable to control a fuel pressure applied to a part of the PRSOV urging the PRSOV towards a closed position, wherein the control valve arrangement is supplied with fuel at a pressure controlled by a variable fluid pressure potentiometer network including a variable flow restrictor which is variable in response to changes in the position occupied by the PRSOV.

Abstract: An engine windmill relight method is described for use with a fuel control system (FCS) having a metering valve (MV), the method comprising the steps of determining a desired fuel delivery rate, and moving the MV to a nominal fuel delivery setting higher than that corresponding to the desired fuel delivery rate.

Abstract: A drive arrangement comprising a drive shaft, a clutch arrangement operable, upon axial movement of the drive shaft occurring, to interrupt drive to the drive shaft, an axially movable interrupt shaft, a gear arrangement whereby the interrupt shaft is driven for rotation by the drive shaft at a speed slower than the rotary speed of the drive shaft, disconnect means operable to cause axial movement of the interrupt shaft, and transmission means for transmitting axial movement of the interrupt shaft to the drive shaft.

Abstract: An electrical equipment device arrangement comprises an electrical equipment device (EED) including an environmental sensor, and a processor device, the environmental sensor and processor device being operable to monitor the environmental conditions to which the EED has been exposed, and to output signals indicative of the impact of the environmental conditions upon the operability and/or availability of the EED.

Abstract: A fuel pumping system comprises a high pressure pump having a drive input, a drive gear driven for rotation, in use, by the drive input, an idler gear driven by the drive gear, and an output gear driven by the idler gear, wherein the output gear is arranged to drive a rotor of an electrical generator and the idler gear is arranged to drive a rotor of a low pressure pump.

Abstract: A fluid flow control system includes a valve, in which a control element regulates flow through a metering orifice. A further control element regulates flow through an orifice downstream of the orifice and is responsive to the pressure downstream of the orifice and to an opposing control pressure on a line. The element is positioned in accordance with the pressure in a chamber controlled by an electrical valve. The pressure in line is set to provide a required pressure drop across the orifice.

Abstract: A brake assembly for a motor, the brake assembly comprising a stack of brake elements, at least one of which is rotatable with an output shaft of the motor, in use, and at least one of which is non-rotatable relative to a housing, and actuator means controlling the magnitude of a compressive load applied to the brake elements, wherein the brake elements are provided, at least in part, with a surface coating which raises the coefficient of friction of the brake elements to a value greater than 0.2. The invention also relates to a brake assembly comprising a plurality of brake elements and an electromagnetic actuator arranged to permit control of a compressive load applied to the brake elements, wherein the actuator includes a winding located such that the brake elements are accessible without requiring removal of the winding from the motor.

Abstract: A control system is described that comprises a manifold, at least one valve device operable to control the delivery of fluid from the manifold, and a drive member located within the manifold and rotatable to control the operation of the at least one valve device.

Abstract: A gear pump arrangement comprising a pair of intermeshing gears (16, 18) located between bearing blocks (24) and rotatable to pump fluid from an inlet (12) to an outlet (14), wherein at least one of the bearing blocks (24) comprises a body (28) formed with a recess (32) within which an insert (34) is located, the recess (32) and insert (34) being shaped so as to be of smaller dimensions at a bearing surface (30) of the bearing block (24) than at a point remote therefrom.