Abstract: A heat exchange device comprising a fluid flow passage having a plurality of successive segments in fluid flow communication with one another, the segments being adapted to maintain a developing flow therein and thereby improve heat transfer.

Abstract: A low-inductance capacitor assembly (12) is provided. The capacitor assembly (12) includes a positive terminal plate (16), a negative terminal plate (18) and an array (20) of capacitors (22) disposed between and electrically coupled to the positive terminal plate (16) and the negative terminal plate (18). A passage (30) extends through the positive terminal plate (16), the negative terminal plate (18) and through a void (35) formed within the array (20) of capacitors (22). The passage (30) may allow routing of a conductor (14) through the capacitor assembly (12).

Abstract: A method for purging fuel from a fuel system of a gas turbine engine on shutdown of the engine comprises, in one aspect, terminating a fuel supply to the fuel system and using the residual compressed air to create a reversed pressure differential in the fuel system relative to a forward pressure differential of the fuel system used to maintain fuel supply for engine operation, and under the reversed pressure differential substantially purging the fuel remaining in the system therefrom to a fuel source.

Abstract: An electric machine is formed by a stator and a rotor that is free to rotate about an axis of rotation. The stator may have teeth projecting from a body portion and that define slots for housing electrical windings. The rotor may have a rotor core and a number of magnets supported on a peripheral face of the rotor in substantially contiguous arrangement and of alternating magnetization. The rotor magnets are shaped so that pairs of adjacent magnets oppose one another along magnetic boundary lines that are skewed relative to the slots formed in the body portion of the stator. For example, the shape of the rotor magnets may be arcuate trapezoidal or parallelogramatic. In this configuration, cogging torque experienced by the rotor during operation of the electric machine may be reduced.

Abstract: Systems and methods for detecting a shaft shear event in a turbine engine. An accelerometer coupled to the engine detects an axial acceleration indicative of a shaft shear event in the engine. A control system is configured to, in response to the detected axial acceleration, transmit a signal to initiate a shut down of a fuel system of the engine.

Abstract: The tandem electric machine arrangement comprises an outside rotor having two axially spaced-apart sets of circumferentially-disposed permanent magnets. It also comprises an inside stator having at least two electrically-independent windings, the at least two windings axially spaced apart from one another and disposed relative to the magnet sets to thereby be magnet coupled to a respective one of the sets of permanent magnets during rotation of the rotor. One of the rotor and the stator is provided in two separate pieces, each piece supported from opposite axial sides of the electric machine relative to one another. The other of the rotor and the stator is supported from substantially centrally of the two pieces.

Abstract: Matrices of multiple cast conductors, and methods for making such matrices are disclosed. Methods according to the disclosure comprise: casting a conductor matrix including a plurality of conductors joined by at least one link; applying a surface treatment to at least a portion of the matrix; finishing a contact face on at least one of the conductors; and separating the conductors from each other at the at least one link.

Abstract: Systems and methods for generating a signal useful in the commutation of current through windings of brushless direct current electric motors are provided. Such methods comprises detecting a kickback pulse in a non-driven winding of a motor; detecting a rotor-induced zero crossing in the non-driven winding following the detection of the kickback pulse; and using the detection of the rotor-induced zero crossing to generate a signal useful in commutation of the motor.

Abstract: The electric machine comprises at least one winding made of a material having a temperature dependent resistance. The temperature of the winding is monitored using the resistance therein. Temperatures or resistances indicative of a fault can be sensed, and corrective action taken, without the need for dedicated temperature sensors.

Abstract: The gas turbine engine comprises at least one electrical generator and an electrical heater associated with a gas path of the engine. The heater is powered by the generator to selectively add heat to the gas turbine cycle.

Abstract: The electric machine comprises at least one winding made of a material having a temperature dependent resistance. The temperature of the winding is monitored using the resistance therein. Temperatures or resistances indicative of a fault can be sensed, and corrective action taken, without the need for dedicated temperature sensors.

Abstract: The tandem electric machine arrangement comprises an outside rotor having two axially spaced-apart sets of circumferentially-disposed permanent magnets. It also comprises an inside stator having at least two electrically-independent windings, the at least two windings axially spaced apart from one another and disposed relative to the magnet sets to thereby be magnet coupled to a respective one of the sets of permanent magnets during rotation of the rotor. One of the rotor and the stator is provided in two separate pieces, each piece supported from opposite axial sides of the electric machine relative to one another. The other of the rotor and the stator is supported from substantially centrally of the two pieces.

Abstract: A power generating apparatus for use with an aircraft gas turbine engine has a low pressure spool assembly which includes an electrical generator. The electrical generator includes a generator stator supported on a stationary structure of the engine and a generator rotor rotatable around the generator stator and mounted to the low pressure spool assembly.

Abstract: A hybrid control system for controlling an electric machine coupled to a gas turbine engine is provided. The control system comprises: a primary analog control loop including an analog controller for controlling the electric machine based on a set point and a measured output of the electric machine; and a digital controller of the turbine engine operationally connected to the primary analog control loop to adjust at least one control parameter associated with the analog controller.

Abstract: The tandem electric machine arrangement comprises an outside rotor having two axially spaced-apart sets of circumferentially-disposed permanent magnets. It also comprises an inside stator having at least two electrically-independent windings, the at least two windings axially spaced apart from one another and disposed relative to the magnet sets to thereby be magnetically coupled to a respective one of the sets of permanent magnets during rotation of the rotor. One of the rotor and the stator is provided in two separate pieces, each piece supported from opposite axial sides of the electric machine relative to one another. The other of the rotor and the stator is supported from substantially centrally of the two pieces.

Abstract: A multi-engine system 10 for use on an aircraft 14 is disclosed. The system 10 may comprise a first aircraft engine 16A and a second aircraft engine 16B configured to drive at least one device 12 of the aircraft 14. A starter 20 may be coupled to one of the first and second aircraft engines 16A, 16B to assist starting of the one of the first and second aircraft engines 16A, 16B. An energy source 24 may be configured to deliver energy to the starter 20 at a rapid rate during rapid starting of the one of the first and the second aircraft engines 16A, 16B, the rapid rate being higher than a regular rate used during regular starting of the one of the first and the second aircraft engines 16A, 16B. The energy source 24 may comprise at least one supercapacitor.

Abstract: A heat exchange device comprising a fluid flow passage having a plurality of successive segments in fluid flow communication with one another, the segments being adapted to maintain a developing flow therein and thereby improve heat transfer.

Abstract: An electric alternator/motor having a stator with at least two non-overlapping sectors is provided. Each sector includes a first winding, first and second magnetic circuits and a saturation control assembly. A cross-talk reduction feature, such as a peripheral slit is provided between each sector of the stator for impeding magnetic flux crossing between the sectors.

Abstract: An electric machine assembly with fail-safe arrangement is described. The assembly comprises a stator including a plurality of windings and a cooperating rotor including at least one permanent magnet; a detector configured to detect DC current in at least one of the windings of the stator; and a bypass circuit configured to be activated upon detection of the DC current by the detector and to prevent at least some of the DC current from flowing into the at least one of the windings of the stator.

Abstract: A position sensing circuit (14) for a brushless electric motor (10) is described. The position sensing circuit (14) comprises an input (16) adapted to receive a voltage induced by a rotor (1) in at least one winding (L1, L2 and L3) of the stator (2) when that winding is not driven; and a detection device (18) inductively coupled to the input (16) and configured to generate a signal representative of a position of the rotor (1) in relation to the stator (2) based on the induced voltage.