Abstract: A gas turbine engine for an aircraft. The gas turbine engine comprises a rotatable shaft defining a rotational axis extending between rearward and forward ends of the gas turbine engine and a compressor drum surrounding, and coupled to, the shaft so as to define an annular gap therebetween. The gas turbine engine further comprises an intermediate case arranged axially rearward of the compressor drum and comprising a bearing support element extending into the annular gap, and a forward bearing mounted between the bearing support element and the shaft proximate a forward end of the compressor drum.

Abstract: An aircraft cabin blower system includes a transmission configured to receive mechanical power from a gas turbine engine in the form of a first transmission input; and an electrical circuit including a first electrical machine, a second electrical machine, and power management system, wherein, when operating in a blower mode, the first electrical receives mechanical power from the gas turbine engine and act as a generator to provide electrical power to the power management system, and the second electrical machine acts as a motor providing mechanical power to the transmission in the form of a second transmission input, the second electrical machine being driven by electrical power from the power management system. The transmission's output drives a cabin blower compressor when operating in the blower mode, a speed of the output of the transmission being determined by a function of a speed of the first and second transmission inputs.

Abstract: A variable diffuser comprises a passage, at least two vanes disposed within the passage, and at least two pennies. The passage is defined between opposing disk faces of a hub and a tip. Each of the vanes comprises a body having a leading edge and a trailing edge. The body extends between the hub face and the disk face. Each of the pennies is coupled to a respective vane body near an edge of the penny and an actuator. Rotation of at least one penny changes the orientation of the respective vane relative to the hub face.

Abstract: An aircraft cabin blower system includes: a transmission configured to receive mechanical power from a first part of a gas turbine engine in the form of a first transmission input; and an electrical circuit including a first electrical machine, a second electrical machine, and a power management system, wherein an output of the transmission is configured to drive a cabin blower compressor when operating in a blower mode, the first electrical machine being configured to receive mechanical power from a second part of the gas turbine engine and act as a generator to provide electrical power to the power management system, and the second electrical machine being configured to act as a motor providing mechanical power to the transmission in the form of a second transmission input, the second electrical machine being driven by electrical power from the power management system.

Abstract: A variable diffuser comprises a passage, at least two vanes disposed within the passage, and at least two pennies. The passage is defined between opposing disk faces of a hub and a tip. Each of the vanes comprises a body having a leading edge and a trailing edge. The body extends between the hub face and the disk face. Each of the pennies is coupled to a respective vane body near an edge of the penny and an actuator. Rotation of at least one penny changes the orientation of the respective vane relative to the hub face.

Abstract: A gas turbine engine for an aircraft. The gas turbine engine comprises a rotatable shaft defining a rotational axis extending between rearward and forward ends of the gas turbine engine and a compressor drum surrounding, and coupled to, the shaft so as to define an annular gap therebetween. The gas turbine engine further comprises an intermediate case arranged axially rearward of the compressor drum and comprising a bearing support element extending into the annular gap, and a forward bearing mounted between the bearing support element and the shaft proximate a forward end of the compressor drum.

Abstract: When in long term storage, battery degradation is avoided by performing battery charge cycles at a voltage level where a change in the battery's voltage divided by a change in the battery's storage capacity is at a minimum, rather than discharging the battery to its minimum storage capacity and then charging to its maximum storage capacity. Further, based on physical and practical limitations, such battery charge cycles can instead be performed within a range or delta Depth of Discharge (“DOD”) and corresponding battery voltage levels rather than at a single voltage level, while still avoiding battery degradation.

Abstract: A gas turbine engine is disclosed having a tip clearance control system. The tip clearance control system has a cabin blower system, a casing arranged in use about a rotor of a gas turbine engine and a fluid delivery passage. The cabin blower system having a cabin blower compressor arranged in use to compress fluid used in a cabin of an aircraft and to compress fluid conducted via the fluid delivery passage into heat exchange with the casing.

Abstract: When in long term storage, battery degradation is avoided by performing battery charge cycles at a voltage level where a change in the battery's voltage divided by a change in the battery's storage capacity is at a minimum, rather than discharging the battery to its minimum storage capacity and then charging to its maximum storage capacity. Further, based on physical and practical limitations, such battery charge cycles can instead be performed within a range or delta Depth of Discharge (“DOD”) and corresponding battery voltage levels rather than at a single voltage level, while still avoiding battery degradation.

Abstract: The invention relates to a gas turbine engine, in particular an aircraft engine, comprising: a turbine connected via an input shaft device to a gearbox device having a sun gear, a planet carrier having a plurality of planet gears attached thereto, and a ring gear, the sun gear is connected to the input shaft device, the planet carrier or the ring gear is connected to a propulsive fan via an output shaft device of the gearbox device, with an inter-shaft bearing system being positioned radially between the input shaft device and the planet carrier of the gearbox device.

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 variable diffuser comprises a passage, at least two vanes disposed within the passage, and at least two pennies. The passage is defined between opposing disk faces of a hub and a tip. Each of the vanes comprises a body having a leading edge and a trailing edge. The body extends between the hub face and the disk face. Each of the pennies is coupled to a respective vane body near an edge of the penny and an actuator. Rotation of at least one penny changes the orientation of the respective vane relative to the hub face.

Abstract: A variable diffuser comprises a passage, at least two vanes disposed within the passage, and at least two pennies. The passage is defined between opposing disk faces of a hub and a tip. Each of the vanes comprises a body having a leading edge and a trailing edge. The body extends between the hub face and the disk face. Each of the pennies is coupled to a respective vane body near an edge of the penny and an actuator. Rotation of at least one penny changes the orientation of the respective vane relative to the hub face.

Abstract: A gas turbine engine, including: a low pressure spool having a low pressure compressor and a low pressure turbine connected by a low pressure shaft; a reduction gear train having a sun gear, a carrier having a plurality of planet gears attached thereto, and a ring gear, wherein one of the sun gear, carrier or ring gear is connected to the low pressure shaft, and another of the sun gear, carrier and ring gear provides an output drive; a propulsive fan mounted fore of the gear train; a fan shafting arrangement comprising a fan shaft which is connected to the output drive of the gear train and a fan support shaft which passes through center of the gear train along the axis of rotation of the gearbox and fan, wherein the fan shafting arrangement is rotatably supported by at least two axially separated bearings.

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: An aircraft cabin blower system includes a transmission configured to receive mechanical power from a gas turbine engine in the form of a first transmission input; and an electrical circuit including a first electrical machine, a second electrical machine, and power management system, wherein, when operating in a blower mode, the first electrical receives mechanical power from the gas turbine engine and act as a generator to provide electrical power to the power management system, and the second electrical machine acts as a motor providing mechanical power to the transmission in the form of a second transmission input, the second electrical machine being driven by electrical power from the power management system. The transmission's output drives a cabin blower compressor when operating in the blower mode, a speed of the output of the transmission being determined by a function of a speed of the first and second transmission inputs.

Abstract: A transmission for receiving mechanical power from a gas turbine engine; and a cabin blower compressor, an output of the transmission being configured to drive the cabin blower compressor; wherein the transmission has a variable gear ratio and the cabin blower compressor has a variable geometry, wherein variation of the gear ratio and the geometry provides a variable output of the cabin blower compressor.

Abstract: An aircraft cabin blower system includes: a transmission configured to receive mechanical power from a first part of a gas turbine engine in the form of a first transmission input; and an electrical circuit including a first electrical machine, a second electrical machine, and a power management system, wherein an output of the transmission is configured to drive a cabin blower compressor when operating in a blower mode, the first electrical machine being configured to receive mechanical power from a second part of the gas turbine engine and act as a generator to provide electrical power to the power management system, and the second electrical machine being configured to act as a motor providing mechanical power to the transmission in the form of a second transmission input, the second electrical machine being driven by electrical power from the power management system.

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: A gas turbine engine (10) comprises: a low pressure compressor (18) comprising a centrifugal compressor stage (24); a low pressure turbine (44) configured to drive a load (12), the low pressure turbine (44) being provided rearwardly of the low pressure compressor (18); a high pressure turbine (42) provided rearwardly of the low pressure turbine (44); a combustor (40) provided rearwardly of the high pressure turbine (42); a high pressure compressor (32) provided rearwardly of the combustor (40); and an intercooler heat exchanger (28) configured to exchange heat between core airflow (B) exiting the low pressure compressor (18) and fan airflow (A), wherein the high pressure turbine (42) and high pressure compressor (32) are coupled by a high pressure shaft (46), and the low pressure turbine (44), low pressure compressor (18) and load (12) are coupled by a low pressure shaft (22).