A propulsion system for an includes a combustion engine, a propulsor, and an electric machine configured to either be driven by the combustion engine or configured to drive the propulsor. The electric machine defines an axis. The electric machine includes a rotor extending along and rotatable about the axis, and a stator having a plurality of winding assemblies, the plurality of winding assemblies spaced along the axis of the electric machine, each winding assembly operable with the rotor independently of an adjacent winding assembly during operation of the electric machine.

A gas turbine engine comprises a low speed spool and a high speed spool, with each of the spools including a turbine to drive a respective one of the spools. The high speed spool rotates at a higher speed than the low speed spool. A high speed power takeoff is driven to rotate by the high speed spool, and a low speed power takeoff is driven to rotate by the low speed spool. The high speed power takeoff drives a starter generator and a permanent magnet alternator. The low speed power takeoff drives a variable frequency generator.

A method of integrating an electric motor or generator as part of an aircraft engine shaft. The motor is used to rotate the rotor so as to cool the rotor in a temperature gradient. The generator is used to provide power to the aircraft.

A permanent magnet electrical machine (30) comprising a first shaft having a rotational axis (34). A second shaft spaced from the first shaft and rotating about the rotational axis. The second shaft comprises magnetic material. A first magnet mounted to the first shaft or aligned with the first shaft to selectively magnetise at least a portion of the first shaft. A second magnet aligned with the second shaft to selectively magnetise at least a portion of the second shaft and thereby to couple the second shaft to the first shaft.

A gas turbine engine comprises an electronic control unit adapted to control functions of the gas turbine engine and having a DC power input unit coupled to receive DC supply power and an ignition igniter coupled thereto. The ignition exciter includes an AC power input unit adapted to receive AC power from an AC power source within the gas turbine engine, a power rectification unit coupled to receive the AC power from the AC power source and configured, upon receipt thereof, to rectify the AC power into DC power, and a DC power output unit coupled to receive the DC power from the power rectification unit and configured to supply the DC power to the DC power input unit of the electronic control unit as DC supply power and/or the ignition igniter.

The present invention is directed to a direct-drive fan system and a variable process control system for efficiently managing the operation of fans in a cooling system such as a wet-cooling tower or air-cooled heat exchanger (ACHE), HVAC systems, mechanical towers or chiller systems. The present invention is based on the integration of key features and characteristics such as tower thermal performance, fan speed and airflow, motor torque, fan pitch, fan speed, fan aerodynamic properties, and pump flow. The variable process control system processes feedback signals from multiple locations in order control a high torque, variable speed, permanent magnet motor to drive the fan. Such feedback signals represent certain operating conditions including motor temperature, basin temperature, vibrations, and pump flow rates. Other data processed by the variable process control system in order to control the motor include turbine back pressure set-point, condenser temperature set-point and plant part-load setting. The variable process control system processes this data and the aforesaid feedback signals to optimize the operation of the cooling system in order to prevent disruption of the industrial process and prevent equipment (turbine) failure or trip. The variable process control system alerts the operators for the need to conduct maintenance actions to remedy deficient operating conditions such as condenser fouling. The variable process control system increases cooling for cracking crude and also adjusts the motor RPM, and hence the fan RPM, accordingly during plant part-load conditions in order to save energy.

A shrouded fan assembly for use with a gas turbine engine includes a central hub and a plurality of variable-pitch fan blades coupled to and extending radially outward from the central hub. Each variable-pitch fan blade includes a radially outer tip is rotatable about a longitudinal axis extending therethrough. A shroud is coupled to each radially outer tip.

An example electrical machine is described that includes active segments for variable voltage generation. The electrical machine includes a drive shaft, a fixed rotor segment, an active rotor segment, and an actuator mechanism. The fixed rotor segment is coupled to the drive shaft, where the fixed rotor segment has affixed thereon first permanent magnets of alternating polarity. The active rotor segment axially is adjacent to the fixed rotor segment along the drive shaft. The active rotor segment also has affixed thereon second permanent magnets of alternating polarity. The actuator mechanism is configured to articulate the active rotor segment relative to the fixed rotor segment and thereby alter a phase of the second permanent magnets relative to the first permanent magnets in order to change a first voltage generated by the electrical machine to a second voltage generated by the electrical machine.

An electrical assembly for an aeronautical turbomachine, including an electric machine configured to be disposed in a turbomachine and comprising a stator and a rotor comprising magnets, the assembly including a short-circuit detecting means, a hot air injecting means configured to draw hot air off the turbomachine at a temperature greater than the temperature of demagnetization of the magnets of the rotor, and to inject the drawn hot air onto the magnets of said rotor when the short-circuit detecting means detects the presence of a short-circuit in the electric machine, and a cool air injecting means, configured to draw cool air off the turbomachine and to inject it into an inner chamber of the turbomachine, the temperature of the cool air drawn by the cool air injecting means being less than the temperature of the hot air drawn by the hot air injecting means.

A gas turbine engine includes a compressor section and a turbine section together defining a core air flowpath. Additionally, a rotary component is rotatable with at least a portion of the compressor section and at least a portion of the turbine section. An electric machine is mounted coaxially with the rotary component and positioned at least partially inward of the core air flowpath along a radial direction of the gas turbine engine. A cavity wall defines at least in part a buffer cavity surrounding at least a portion of the electric machine to thermally insulate the electric machine, e.g., from the relatively high temperatures within the core air flowpath.