Abstract: An aircraft cabin blower system is described having a hydraulic circuit comprising a first hydraulic device and a second hydraulic device. The first hydraulic device is mechanically coupled to a cabin blower compressor and the second hydraulic device is arranged in use to be mechanically coupled to a spool of a gas turbine engine. The first hydraulic device is capable of performing as a hydraulic motor and the second hydraulic device is capable of performing as a hydraulic pump. When, in use, the system is operating in a cabin blower configuration, a driving force supplied by the spool of the gas turbine causes the second hydraulic device to pump liquid provided in the hydraulic circuit and thereby to drive the first hydraulic device, which in turn rotates the cabin blower compressor.

Abstract: A gas turbine engine including an intake, a fan and an injector system. The intake has an inner wall which defines an intake passage for the fan. The injector system includes a cabin blower system including a cabin blower compressor arranged in use to compress fluid used in a cabin of an aircraft and by the injector system. The intake includes an injector of the injector system through which in use fluid from the cabin blower compressor is injected into a main airflow for flow control of air on the way to the fan.

Abstract: A gas turbine engine includes a turbine and a turbine cooling arrangement. The turbine includes a turbine rotor surrounded by a static rotor track liner, and a nozzle guide vane downstream of the rotor in a core main gas flow path. The cooling arrangement includes a first air duct that provides cooling airflow to a rotor track liner cooling plenum and a second air duct that provides a cooling airflow to the nozzle guide vane. A common manifold is upstream in the cooling airflow of the ducts and provides cooling air to the ducts. A two-way valve modulates air provided to the ducts from the manifold. The valve is operates in a first or second mode. In the first mode, air flow to the first duct is relatively high and airflow to the second duct is relatively low compared to where the valve is operated in the second mode.

Abstract: A gas turbine engine comprising a compressor, a compressor case surrounding the compressor and a compressor tip injector system is disclosed. The compressor tip injector system comprises a cabin blower system comprising a cabin blower compressor arranged in use to compress air used in a cabin of an aircraft and by the compressor tip injector system. The compressor case comprises one or more injectors of the compressor tip injector system through which in use air from the cabin blower compressor is injected towards blade tip ends of blades of the compressor as they rotate.

Abstract: An aircraft cabin blower system comprising a transmission and a compressor is disclosed. The system has a forward configuration in which the compressor is drivable in use via the transmission. The transmission comprises a toroidal continuously variable transmission giving selectively variable control over the rate at which the compressor is driven.

Abstract: A fan disc is provided for supporting fan blades of a gas turbine engine. The fan disc has a disc body having axially extending slots for receiving, in use, dovetail root fixings of a circumferential row of fan blades. The fan disc further has an annular drive arm which extends radially inwardly from a forward portion of the disc body to a connector for engaging, in use, with a corresponding connector portion of a drive shaft of the engine. The fan disc further has a hoop stiffening ring which is removably mounted to a rear portion of the disc body, the stiffening ring being axially spaced from the drive arm to increase the torsional stiffness of the fan disc.

Abstract: In order to accommodate loading in a number of situations such as with regard to thrusts in a gas turbine engine it is known to provide thrust bearings. These thrust bearings can be large and may be difficult to accommodate. By providing a duplex or multiplex thrust bearing which may be of increased axial length but reduced radial width easier accommodation may be achieved. By providing a thrust element 27 which compromises a balance beam from which extend elastic hinges to a mounting to a fixed bearing frame and ends of bearing races 21, 22 an appropriate thrust response can be achieved dependent upon bearing loads presented through bearing elements 23, 24. By rotation of the balance beam and flexing of the elastic hinges 30, 31, 32 an appropriate bearing load share is achieved.

Abstract: A gas turbine engine comprising first and second rotor shafts and an intershaft rolling element bearing arranged between the shafts. The first rotor shaft has a stator stage and a rotor stage; the second rotor shaft has only a rotor stage and is arranged to contra-rotate relative to the first shaft. The intershaft bearing is arranged between the first and second shafts such that the relative speeds of the shafts minimise a cage speed of the intershaft bearing.

Abstract: A number of machines such as gas turbine engines have asymmetric axial loading along a shaft (2, 3, 4). In order to accommodate for this asymmetric loading, known as an end bearing load, a load share bearing (103) is typically provided. However, specifying the fixed bearing (11, 12) becomes increasingly difficult as space and weight considerations are taken into account. In such circumstances providing a combination of a fixed bearing (11, 12) and a load share bearing (103) to achieve an acceptable bearing end load capacity is more acceptable. The proportion of the combination provided respectively by the fixed bearing and the load share bearing can be varied dependent upon operational stage in order to achieve more efficient operation.

Abstract: A gas turbine engine (10) comprising a first turbine (19) and a first compressor (13) mounted on a first shaft (26) and a bearing arrangement (52, 34) supporting the shaft (26), the bearing arrangement is subject to a total end load and comprises a fixed bearing (34), a load share bearing (52) and a bearing end load management system (50) that is capable of applying a variable load to the load share bearing to manage total end load between the bearings. The bearing end load management system comprises a static diaphragm (54) that defines part of a chamber (56) and that is coupled to the load share bearing whereby increased pressurization of the chamber loads the diaphragm which in turn increases the proportion of the total end load on the load share bearing.

Abstract: A gas feed assembly (30) comprises a compressor arrangement (32) comprising first and second compressor (34, 36). The gas feed assembly includes an outlet (42) for gas for the first and second compressors (34, 36). The gas feed assembly includes a first inlet (38) for the first compressor (34) and a second inlet (40) for the second compressor (36). The gas feed assembly further includes a valve assembly (52, 64) for allowing gas to enter either, or both, of the first and second compressors from at least one gas source.

Abstract: In order to accommodate loading in a number of situations such as with regard to thrusts in a gas turbine engine it is known to provide thrust bearings. These thrust bearings can be large and may be difficult to accommodate. By providing a duplex or multiplex thrust bearing which may be of increased axial length but reduced radial width easier accommodation may be achieved. By providing a thrust element 27 which compromises a balance beam from which extend elastic hinges to a mounting to a fixed bearing frame and ends of bearing races 21, 22 an appropriate thrust response can be achieved dependent upon bearing loads presented through bearing elements 23, 24. By rotation of the balance beam and flexing of the elastic hinges 30, 31, 32 an appropriate bearing load share is achieved.

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 cooling system for a gas turbine engine (FIG. 1) comprises a pre-swirl arrangement, preferably including a pre-swirl chamber, for providing cooling air to a turbine blade disc, and a ventilation arrangement for providing ventilation air to a rotating component of the gas turbine engine. The cooling system includes an air bypass arrangement, which preferably includes first, second and third air bypass duct portions, for conveying ventilation air away from the pre-swirl arrangement.

Abstract: A generator assembly for a gas turbine engine. The assembly includes an electrical generator connected via a first sprag clutch to an accessory gearbox driven by the engine. The generator is also connected by a second sprag clutch to an air turbine connected to engine bleed valves which are selectively open when the engine speed falls below a predetermined level. The clutches are arranged such that the generator is driven at any time by the fastest rotating of the gearbox and turbine.

Abstract: A drive arrangement for driving, or for being driven by, a fluid is disclosed. The drive arrangement comprises a rotatable member (40) for receiving the fluid, and having mounted thereon a plurality of drive members (56). The drive members (56) are movable between a drive position, in which the drive members can drive, or be driven by, the fluid, and a non-drive position in which the drive members (56) are substantially prevented from driving or being driven by a fluid received in the rotatable member (40).

Abstract: A gas turbine engine comprising a core engine surrounded by a core casing, at least one C-duct having radially inner and outer walls and a thrust reverser unit; the engine is mounted to an aircraft pylon via at least one thrust member attached to the core engine; the thrust reverser unit is mounted within the outer wall of the C-duct; the C-duct is secured to the core casing via a vee-groove attachment comprising vee-groove and vee-blade parts, the attachment is arranged to transfer loads between the thrust reverser unit and the pylon; wherein one cooperating part of the attachment is mounted to a torsion box mounted on the inner wall of the C-duct.

Abstract: A number of machines such as gas turbine engines have asymmetric axial loading along a shaft (2, 3, 4). In order to accommodate for this asymmetric loading, known as an end bearing load, a load share bearing (103) is typically provided. However, specifying the fixed bearing (11, 12) becomes increasingly difficult as space and weight considerations are taken into account. In such circumstances providing a combination of a fixed bearing (11, 12) and a load share bearing (103) to achieve an acceptable bearing end load capacity is more acceptable. The proportion of the combination provided respectively by the fixed bearing and the load share bearing can be varied dependent upon operational stage in order to achieve more efficient operation.

Abstract: A gas turbine engine (10) comprising a first turbine (19) and a first compressor (13) mounted on a first shaft (26) and a bearing arrangement (52, 34) supporting the shaft (26), the bearing arrangement is subject to a total end load and comprises a fixed bearing (34), a load share bearing (52) and a bearing end load management system (50) that is capable of applying a variable load to the load share bearing to manage total end load between the bearings. The bearing end load management system comprises a static diaphragm (54) that defines part of a chamber (56) and that is coupled to the load share bearing whereby increased pressurisation of the chamber loads the diaphragm which in turn increases the proportion of the total end load on the load share bearing.

Abstract: A gas turbine engine comprising a core engine surrounded by a core casing, at least one C-duct having radially inner and outer walls and a thrust reverser unit; the engine is mounted to an aircraft pylon via at least one thrust member attached to the core engine; the thrust reverser unit is mounted within the outer wall of the C-duct; the C-duct is secured to the core casing via a vee-groove attachment comprising vee-groove and vee-blade parts, the attachment is arranged to transfer loads between the thrust reverser unit and the pylon; wherein one cooperating part of the attachment is mounted to a torsion box mounted on the inner wall of the C-duct.