Abstract: An electric machine includes a generally annular outer rotor supported to rotate about a rotational axis. The outer rotor defines an internal cavity therein and has a plurality of permanent magnets in the internal cavity generating a first magnetic field. An inner rotor is in the internal cavity and is supported to rotate about the rotational axis. The inner rotor has a plurality of permanent magnets about its perimeter that generate a second magnetic field. A generally annular stator is in the internal cavity between the outer rotor and the inner rotor. The stator has a stator winding supported by a non-magnetically conductive stator core. The stator winding is arranged to generate a field that interacts with the first and second magnetic fields. One of the outer rotor or the inner rotor is mechanically coupled to drive a load. The other of the outer rotor or the inner rotor is not mechanically coupled to drive the load.

Abstract: A flywheel interface system for line interactive power correction comprises a flywheel system that includes a flywheel coupled to rotate with a motor/generator. A passive rectifier is coupled to the flywheel system for converting alternating current generated by the flywheel system to direct current. An active inverter is coupled to the passive rectifier for converting the direct current from the passive rectifier to alternating current and to output the alternating current to the load. A motor drive is coupled to the motor/generator of the flywheel system for driving the motor/generator to rotate the flywheel, the motor drive including a second passive rectifier coupled to a second active inverter.

Abstract: An electric machine includes a generally annular outer rotor supported to rotate about a rotational axis. The outer rotor defines an internal cavity therein and has a plurality of permanent magnets in the internal cavity generating a first magnetic field. An inner rotor is in the internal cavity and is supported to rotate about the rotational axis. The inner rotor has a plurality of permanent magnets about its perimeter that generate a second magnetic field. A generally annular stator is in the internal cavity between the outer rotor and the inner rotor. The stator has a stator winding supported by a non-magnetically conductive stator core. The stator winding is arranged to generate a field that interacts with the first and second magnetic fields. One of the outer rotor or the inner rotor is mechanically coupled to drive a load. The other of the outer rotor or the inner rotor is not mechanically coupled to drive the load.

Abstract: A flywheel interface system for line interactive power correction comprises a flywheel system that includes a flywheel coupled to rotate with a motor/generator. A passive rectifier is coupled to the flywheel system for converting alternating current generated by the flywheel system to direct current. An active inverter is coupled to the passive rectifier for converting the direct current from the passive rectifier to alternating current and to output the alternating current to the load. A motor drive is coupled to the motor/generator of the flywheel system for driving the motor/generator to rotate the flywheel, the motor drive including a second passive rectifier coupled to a second active inverter.

Abstract: A rotor construction may comprise a rotor with a centrally located permanent magnet section having aligned magnet segments and having a central hole throughout its length. A thin rod of magnetic steel is located in this central hole to support the permanent magnets from within. At each end of the rod are located threaded sections for attachment to supporting end stubs. A high strength steel sleeve is interference fit over both the magnets and the end stubs to provide a mechanical link from stub to stub. The guide rod insures that the end stubs and central magnet are concentric during initial processing, prevents relative motion between the rotor components and provides support for the magnet once the sleeve is installed.

Abstract: An optimized flywheel energy storage system utilizing magnetic bearings, a high speed permanent magnet motor/generator, and a flywheel member. The flywheel system is constructed using a high strength steel wheel for kinetic energy storage, high efficiency magnetic bearings configured with dual thrust acting permanent magnet combination bearings, and a high efficiency permanent magnet motor generator. The steel wheel provides a cost effective, high speed construction for the energy storage rotor.

Abstract: An improved magnetic bearing that uses permanent magnets to provide the bias flux. The magnetic circuits generating the control flux and bias fluxes are substantially non-coincident but share the same path over some portions that include radial and axial airgaps allowing for a low reluctance and an efficient path for the electromagnetic flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents that produce extremely large forces. A single coil and amplifier for the axial force control and two coils with one associated amplifier for each radial axis of control provides simplicity and cost effectiveness. A single thrust disk is provided that is reacted against for both radial and the axial displacement.

Abstract: A magnetic thrust bearing having a high speed rotation capability and low cost construction. The magnetic thrust bearing has permanent magnets to provide bias flux. The magnetic circuits of the control flux and bias fluxes are substantially non-coincident, which allows for a low reluctance and efficient path for the control flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents produce extremely large forces. No radially magnetized permanent magnets are required and no permanent magnets are attached to the rotor.

Abstract: An improved magnetic bearing that uses permanent magnets to provide the bias flux. The magnetic circuits generating the control flux and bias fluxes are substantially non-coincident but share the same path over some portions that include radial and axial airgaps allowing for a low reluctance and an efficient path for the electromagnetic flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents that produce extremely large forces. A single coil and amplifier for the axial force control and two coils with one associated amplifier for each radial axis of control provides simplicity and cost effectiveness. A single thrust disk is provided that is reacted against for both radial and the axial displacement.

Abstract: A magnetic thrust bearing having a high speed rotation capability and low cost construction. The magnetic thrust bearing has permanent magnets to provide bias flux. The magnetic circuits of the control flux and bias fluxes are substantially non-coincident, which allows for a low reluctance and efficient path for the control flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents produce extremely large forces. No radially magnetized permanent magnets are required and no permanent magnets are attached to the rotor.

Abstract: A magnetic bearing utilizes electromagnets together with a permanent magnet to provide controlled radial and axial (thrust) load support of a shaft including a thrust disc, relative to a housing. In one form, the magnetic bearing includes an arcuate ring of high magnetic flux permeability, and a plurality of electromagnet coils circumferentially positioned about the arcuate ring which generate a radially polarized controllable electromagnetic field. A permanent magnet is spaced radially outwardly from the plurality of electromagnet coils and is linked magnetically to the shaft through both a radial air gap and an axial air gap between the housing and the shaft/thrust disc. A pair of electromagnet coils associated with the arcuate ring and circumscribing a portion of the shaft, generate an axially polarized electromagnetic field which links the shaft to the housing through the axial air gap.

Abstract: An electromagnetic thrust bearing couples a rotatable member relative to a stationary member utilizing a combination of controllable electromagnets and a radially polarized permanent magnet, each physically associated with the stationary member. In one embodiment the rotatable member comprises a shaft having a pair of axially spaced apart thrust discs fixed thereto. A pair of solenoids are disposed about the rotatable member between the spaced apart thrust discs in oppositely facing relating to axially-facing sides of the thrust discs. The solenoids are capable of generating a controllable electromagnetic field. An arcuate radially polarized permanent magnet is disposed between the solenoids to generate a constant flux high density magnetic field between a solenoid housing and the thrust discs. In a second embodiment, a pair of solenoids are disposed about the rotatable member in facing relating on opposite sides of a single thrust disc.