Electric Power Research Institute Incorporated

The United States of America As Represented by the United States

The United States of America As Represented by the Department of Energy

Motor Magnetics

J Milton Bailey

Patrick James McCleer

Jack S Lawler

Robert A Hawsey

Igor Alexeff

Werner H Kreidl

A new class of higher phase-order (five or more) quasi square-wave back emf permanent magnet machines including radial, axial and linear embodiments which employ a greater number of active phase windings during continuous operation, thereby utilizing more of the machine copper and magnet material.

Quasi square-wave back-EMF permanent magnet AC machines with five or

A brushless dc permanent magnet motor drives an autonomous underwater vehe. In one embodiment, the motor comprises four substantially flat stators in stacked relationship, with pairs of the stators axially spaced, each of the stators comprising a tape-wound stator coil, and first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of permanent magnets embedded therein. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and a drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore in which the first shaft is disposed. Two different sets of bearings support the first and second shafts. In another embodiment, the motor comprises two ironless stators and pairs of rotors mounted on opposite sides of the stators and driven by counterrotating shafts.

Disc rotors with permanent magnets for brushless DC motor

An ultra-high speed, axial gap alternator that can provide an output to a plurality of loads, the alternator providing magnetic isolation such that operating conditions in one load will not affect operating conditions of another load. This improved alternator uses a rotor member disposed between a pair of stator members, with magnets disposed in each of the rotor member surfaces facing the stator members. The magnets in one surface of the rotor member, which alternate in polarity, are isolated from the magnets in the other surface of the rotor member by a disk of magnetic material disposed between the two sets of magents. In the preferred embodiment, this disk of magnetic material is laminated between two layers of non-magnetic material that support the magnets, and the magnetic material has a peripheral rim that extends to both surfaces of the rotor member to enhance the structural integrity. The stator members are substantially conventional in construction in that equally-spaced and radially-oriented slots are provided, and winding members are laid in these slots. A unit with multiple rotor members and stator members is also described.

Ultra-high speed permanent magnet axial gap alternator with multiple

In an electromagnetic device a magnet arrangement is provided having an electromagnet and a permanent magnet, with the pole faces of the permanent magnet abutting the core of the electromagnet on both sides of the end portions of the coil of the electromagnet and the end portions of the core of the electromagnet forming or supporting the pole pieces of the magnet arrangement. The poles of the permanent magnet are adjacent the like poles of the electromagnet when the electromagnet is energized, and the maximum value of the energizing current of the electromagnet is sufficient but not greater than necessary for reaching the first practical saturation value of flux density in the pole ends of the core of the magnet arrangement with the permanent magnet removed therefrom.

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Knoxville, TN, United States of America

J Milton Bailey