A method of de-spinning a rotor of a propulsion system includes providing one or more spinning rotors rotatably mounted on a frame with a bearing having a bearing outer race, bearing balls, and bearing inner race; providing a force mechanism coupled with the one or more spinning rotors for applying a load to the one or more spinning rotors; and loading an outer portion of the outer bearing race, bearing ball, and inner bearing race of the bearing, a load on the outer portion of the bearing race, bearing ball, and inner bearing race of the bearing corresponding to a force applied to the one or more spinning rotors by the drive mechanism. The one or more spinning rotors de-spin at a rate corresponding to the load on the bearing balls.

A rotational motor includes a stator and a rotor and at least two magnets including a permanent magnet and an electromagnet, wherein one of the magnets is attached to the stator and one of the magnets is attached to the rotor. The magnets are relatively aligned such that when the electromagnet is switched off, the permanent magnet is attracted to a ferromagnetic core of the electromagnet causing the rotor to rotate relative to the stator, and when the electromagnet is switched on, the permanent magnet is repelled from the electromagnet causing the rotor to continue to rotate relative to the stator.

An electric machine includes a stator defining multiple stator poles with associated stator windings configured to receive a stator current. The electric machine also includes a rotor defining multiple fixed rotor poles with associated rotor windings, wherein the rotor defines a field energizable by magnetic fields produced by the stator windings when receiving the stator current to produce relative motion between the rotor and the stator and wherein the rotor is maintained in synchronicity with the magnetic fields produced by the stator during operation of the electric machine. The electric machine also includes a rectification system configured control against an alternating current being induced in the rotor poles as the field is energized by magnetic fields produced by the stator windings when receiving the stator current.

An electric machine includes a stator and a rotor energizable by magnetic fields produced by the stator when receiving a stator current to produce relative motion between the rotor and the stator. A controller is configured to send the stator current through the stator at a current angle measured from the closest one of a pole of the rotor, determine a desired operational output of the electric machine, and determine a desired rotor motion corresponding to the desired operational output of the electric machine. The controller is further configured to calculate a vector control modulation applied to the stator that elicits the desired rotor motion, and adjust the current angle of the stator current based on the vector control modulation to cause the rotor to perform the desired rotor motion and achieve the desired operational output of the electric machine.

A method for controller a multiphase electric machine includes, in response to a determination that a phase of the multiphase electric machine is in an open circuit condition, determining a desired torque to be generated by the multiphase electric machine and retrieving, based on the determination that the phase is in the open circuit condition and the desired torque, a set of current values to be applied to each of the other phases of the multiphase electric machine to achieve the desired torque. The method may also include applying respective current values of the set of current values to corresponding ones of the other phases of the multiphase electric machine, the set of current values being determined based on a model of the multiphase electric machine that includes the phase is in the open circuit condition.

An electric motor assembly includes a stator, rotor, housing, rotatable shaft, and cooling fan. The stator and rotor are at least partly housed in the housing. The shaft is associated with the rotor to rotate about an axis. The cooling fan is fixed to and thereby rotates with the shaft to induce airflow within the housing. The cooling fan includes a wheel plate projecting radially relative to the shaft. The cooling fan further includes a plurality of radial blades that project axially from the wheel plate. The blades define a series of radial channels. The wheel plate defines an axial plate opening therethrough in alignment with a respective one of the channels.

A hybrid excitation rotating electrical machine configured with a rotor having a shaft extended on at least one side in an axial direction, and first and second cores that are separated in the axial direction with a gap between the cores. First magnetic poles that are excited by a permanent magnet and second magnetic poles that are not excited by the permanent magnet are alternately arranged in a circumferential direction in each of the first and second cores. The first magnetic poles of the first core have a different polarity from that of the first magnetic poles of the second core, and the first magnetic poles of one of the first and second cores are placed so as to face the second magnetic poles of the other of the first and second cores in the axial direction with the gap between the magnetic poles.

A rotary electrical machine rotor having claw-shaped poles. The machine comprising a plurality of interpolar magnetic assemblies having at least two magnetic assemblies comprising different magnet grades.

A rotational motor that comprises a stator and a rotor and at least two magnets comprising a permanent magnet and an electromagnet, wherein one of the magnets is attached to the stator and one of the magnets is attached to the rotor. The magnets are relatively aligned such that when the electromagnet is switched off, the permanent magnet is attracted to a ferromagnetic core of the electromagnet causing the rotor to rotate relative to the stator, and when the electromagnet is switched on, the permanent magnet is repelled from the electromagnet causing the rotor to continue to rotate relative to the stator.

A system to reduce eddy currents and the resulting losses in a synchronous motor includes at least one pick-up coil mounted to the rotor. Each pick-up coil may be located proximate a pole on the rotor. A voltage applied to the stator to control the synchronous motor includes both a fundamental component and harmonic components. The fundamental component interacts with a magnetically salient structure in each pole on the rotor to cause rotation of the rotor. The harmonic components induce a voltage in the pick-up coil. The portion of the harmonic components that induce a voltage in the pick-up coil no longer generate eddy currents within the motor. The energy harvested by the pick-up coil may also be utilized in a function other than driving the motor, such as powering a sensor mounted on the rotor.