Abstract: A 3D printed metal coil for an electrical machine. The 3D printed coil has a plurality of turns and is configured to fit within a slot in an electrical machine. A portion of each turn forming an end winding of the coil has a flat plate-like shape for dissipating heat from the end winding.

Abstract: A 3D printed metal coil for an electrical machine. The 3D printed coil has a plurality of turns and is configured to fit within a slot in an electrical machine. A cross-sectional shape of successive turns of the plurality of turns varies such that a portion of each turn forms a part of an external surface of the metal coil, the external surface forming an interface with a side of the slot.

Abstract: A method is provided for fabricating an insulated metal coil for an electrical machine. The method includes 3D printing a metal coil having a plurality of turns. The method further includes subsequently infiltrating insulating material between the turns of the metal coil to electrically insulate the turns from each other.

Abstract: An electrical machine comprising a two-part rotor formed of a first rotor part and a second rotor part. The first rotor part includes a conical section and is mounted to a shaft of the machine. The second rotor part has a bore including a complementary conical section. The second rotor part is configured to displace axially between a first state, in which it is engaged with the first rotor part to form the rotor of the electrical machine, and a second state, in which it is axially disengaged from the first rotor part. Also a clutch having an engaged state and a disengaged state. When the clutch is in one of its states the second rotor part is in its first state and switching the clutch to the other of its states axially displaces the second rotor part to its second state.

Abstract: A method is provided for fabricating an insulated metal coil for an electrical machine. The method includes 3D printing a metal coil having a plurality of turns. The method further includes subsequently infiltrating insulating material between the turns of the metal coil to electrically insulate the turns from each other.

Abstract: A permanent magnet electrical machine has a rotor supporting a circumferential row of permanent magnets and a stator coaxial with the rotor and having a circumferential row of teeth carrying respective coil windings. The teeth provide paths for magnetic flux from the magnets, thereby electromagnetically linking the magnets and coils when the rotor rotates. The teeth have respective core portions on which the coil windings are mounted, and respective tip portions located between the core portions and the rotor. The tip portions are controllably rotatable between a first position where the tip portion and the core portion are angularly aligned to enhance magnetic flux linkage between the magnets and the coils, and a second position in which the tip portion is rotated out of angular alignment with its core portion to reduce magnetic flux linkage between the magnets and the coils. The tip portions are biased to the second position.

Abstract: A sleeve for retaining magnets around a rotor of an electrical machine. The sleeve is cylindrical and hollow, having axial length and having radial thickness between its inner surface and outer surface. The sleeve defines a plurality of axially spaced, circumferentially extending grooves. Each groove has radial depth which is less than the radial thickness of the sleeve.

Abstract: An electrical machine is disclosed comprising a stator cavity. The stator cavity is axially divided by a distribution plate into a winding chamber containing stator windings of the electrical machine and a handling chamber. The handling chamber has one of a fluid inlet and a fluid outlet and the winding chamber has the other of the fluid inlet and fluid outlet. In use fluid is passed from the fluid inlet to the fluid outlet via the handling chamber, the winding chamber and an array of fluid passages in the distribution plate providing fluid communication between the handling chamber and winding chamber. The array of fluid passages comprises passages of at least two different cross-sectional areas.

Abstract: An electrical machine comprising a two-part rotor formed of a first rotor part and a second rotor part. The first rotor part includes a conical section and is mounted to a shaft of the machine. The second rotor part has a bore including a complementary conical section. The second rotor part is configured to displace axially between a first state, in which it is engaged with the first rotor part to form the rotor of the electrical machine, and a second state, in which it is axially disengaged from the first rotor part. Also a clutch having an engaged state and a disengaged state. When the clutch is in one of its states the second rotor part is in its first state and switching the clutch to the other of its states axially displaces the second rotor part to its second state.

Abstract: An electrical machine is disclosed comprising a stator cavity. The stator cavity is axially divided by a distribution plate into a winding chamber containing stator windings of the electrical machine and a handling chamber. The handling chamber has one of a fluid inlet and a fluid outlet and the winding chamber has the other of the fluid inlet and fluid outlet. In use fluid is passed from the fluid inlet to the fluid outlet via the handling chamber, the winding chamber and an array of fluid passages in the distribution plate providing fluid communication between the handling chamber and winding chamber. The array of fluid passages comprises passages of at least two different cross-sectional areas.

Abstract: A sleeve for retaining magnets around a rotor of an electrical machine. The sleeve is cylindrical and hollow, having axial length and having radial thickness between its inner surface and outer surface. The sleeve defines a plurality of axially spaced, circumferentially extending grooves. Each groove has radial depth which is less than the radial thickness of the sleeve.

Abstract: An electrical machine system including a permanent magnet assembly having a magnetic field and a plurality of conductive coils, the magnet assembly and coils arranged for relative rotation between the coils and magnetic field in the manner of an electrical generator or motor, the system further comprising a current injector electrically connected to said coils and arranged selectively to supply a current signal thereto, the current signal being asynchronous with the frequency of rotation between the permanent magnet assembly and coils so as to heat and thereby demagnetise one or more magnet within said permanent magnet assembly.

Abstract: An electromagnetic device, which includes a ferromagnetic flux guide; an insulated electrical conductor positioned adjacent to the ferromagnetic flux guide; and, an intermediate support structure positioned between the ferromagnetic flux guide and conductor which includes at least one resiliently deformable member arranged to allow relative movement between the ferromagnetic flux guide and the insulated electrical conductor, in which the relative movement is due to thermal expansion or contraction of the ferromagnetic flux guide and insulated electrical conductor.

Abstract: An electromagnetic device, which includes a ferromagnetic flux guide; an insulated electrical conductor positioned adjacent to the ferromagnetic flux guide; and, an intermediate support structure positioned between the ferromagnetic flux guide and conductor which includes at least one resiliently deformable member arranged to allow relative movement between the ferromagnetic flux guide and the insulated electrical conductor, in which the relative movement is due to thermal expansion or contraction of the ferromagnetic flux guide and insulated electrical conductor.

Abstract: An electrical machine system including a permanent magnet assembly having a magnetic field and a plurality of conductive coils, the magnet assembly and coils arranged for relative rotation between the coils and magnetic field in the manner of an electrical generator or motor, the system further comprising a current injector electrically connected to said coils and arranged selectively to supply a current signal thereto, the current signal being asynchronous with the frequency of rotation between the permanent magnet assembly and coils so as to heat and thereby demagnetise one or more magnet within said permanent magnet assembly.

Abstract: With variable airgap reluctance actuators problems arise due to the relationship between actuator mass and displacement range. By providing opposed surfaces in the actuator stator core and armature which have undulations typically in the form of grooves, slots and projections, a greater displacement range can be achieved whilst maintaining performance above a rated displacement force characteristic. In such circumstances by establishing a necessary rated displacement force characteristic, an actuator can be tailored and designed to meet that characteristic over a desired displacement range which has significantly less mass in comparison with a prior actuator arrangement having flat surfaces.

Abstract: Control of blade clearance gaps between rotating turbine blades and an associated casing in a gas turbine engine is important in order to maintain operational efficiency. It is desirable to achieve accurate gap control but previous passive and scheduled thermal gap adjustment systems have been relatively course. By provision of a winding through which a specific electrical current is passed in order to create electro-magnetic force for displacement of an armature associated with a seal forming part of the casing it is possible to adjust the gap between that seal and a tip part of a rotating blade assembly. Normally a blade gap monitoring technique is used in association with specific operational requirements with respect to the gap by the control in order to determine the electrical current presented to the winding.

Abstract: Apparatus indicated generally at 26 is incorporated within an aircraft. The apparatus 26 includes an electric motor 28, a first drive train 30 and a second drive train 32. The first drive train 30 provides drive from the electric motor 28 for one or more of the wheels 20, allowing the electric motor 28 to propel the aircraft when taxiing. The second drive train 32 provides drive from the electric motor 28 for an aircraft system which is operational at least when the aircraft is in flight. In this example, the electric motor 28 is illustrated using the second drive train 32 for driving a compressor 34 of the ECS 24, the compressor 34 being responsible for cabin pressurisation during flight. A clutch 36 allows the drive train 30 to be connected or disconnected from the electric motor 28, thereby connecting or disconnecting the drive from the electric motor 28 to the wheels 20. The clutch 36 is controlled to disconnect the first drive train 30 when the aircraft is in flight.

Abstract: Control of blade clearance gaps between rotating turbine blades and an associated casing in a gas turbine engine is important in order to maintain operational efficiency. It is desirable to achieve accurate gap control but previous passive and scheduled thermal gap adjustment systems have been relatively course. By provision of a winding through which a specific electrical current is passed in order to create electro-magnetic force for displacement of an armature associated with a seal forming part of the casing it is possible to adjust the gap between that seal and a tip part of a rotating blade assembly. Normally a blade gap monitoring technique is used in association with specific operational requirements with respect to the gap by the control in order to determine the electrical current presented to the winding.

Abstract: A variable reluctance electric machine comprising a rotor and a stator; the stator having two or more electromagnetic windings and the rotor having a plurality of salient poles, the salient poles defining axially extending cooling fluid channels; wherein the salient poles and the cooling fluid channels are circumferentially skewed along at least a part of their length whereby in use the cooling fluid channels impel cooling fluid in a substantially axial direction towards the electromagnetic windings and the stator to facilitate heat transfer and dissipation from the windings.