Dura-trac Motors, Inc.

Medlin, Jerry W.

Zepp, Lawrence P.

Jerry W Medlin

Lawrence P Zepp

A permanent magnet motor/generator that includes a stator, a rotor provided with a plurality of permanent magnets at a peripheral surface thereof and having a central axis which coincides with the central axis of the stator, a rotatable shaft upon which the rotor is coupled, and an actuator for moving the rotor with respect to the stator axially along the rotatable shaft a sufficient distance to completely decouple the rotor from the stator so as to eliminate magnet induced torque drag. When the permanent magnet/generator is used in parallel hybrid vehicles, the ability to completely decouple the rotor from the stator greatly improves range and efficiency. In addition, by progressively engaging the rotor with the stator a desired voltage output can be obtained upon deceleration.

Brushless permanent magnet motor/generator with axial rotor decoupling to eliminate magnet induced torque losses

A brushless permanent magnet electric machine with a fixed radial air gap is operated to a much higher speed than normal maximum speed by the reduction in effective magnet pole strength. Permanent magnets are supported on the inner surface of an axially movable cylindrical shell. A plurality of magnetic poles provided with wire coils are supported on a stationary cylindrical member cooperate with the permanent magnets on the axially movable cylindrical shell to either cause, or react to, rotation of the axially movable cylindrical shell. The axially movable cylindrical shell and cylindrical member are coaxial. The cylindrical shell is axially movable with respect to the cylindrical member.

Brushless permanent magnet wheel motor with variable axial rotor/stator alignment

A brushless permanent magnet electric machine with a fixed radial air gap is operated to a much higher speed than normal maximum speed by the reduction in effective magnet pole strength. Increasing the amount of axial misalignment of the permanent magnet rotor and constant velocity bearing proportionally increases the speed and reduces the torque. The permanent magnet rotor is offset axially to provide axial misalignment between the rotor magnet poles and the stator, reducing the effective magnet pole strength or flux to the stator. An integral constant velocity linear bearing is used to couple the movable rotor and the fixed position motor shaft. A thrust bearing is actuated to offset the magnetic rotor against the attractive magnetic forces toward the stator. The use of a constant velocity linear bearing allows the motor shaft, radial support bearings, position encoder, cooling fan, and output coupling to remain in a constant position while rotor position is offset.

Brushless permanent magnet motor or alternator with variable axial rotor/stator alignment to increase speed capability

A brushless permanent magnet electric motor with a fixed radial air gap is operated to a much higher speed than normal maximum speed by the reduction in effective magnet pole strength. Increasing the amount of axial misalignment of the permanent magnet rotor and stator proportionally increases the speed and reduces the torque. The permanent magnet rotor is offset axially to provide axial misalignment between the rotor magnet poles and the stator, reducing the effective magnet pole strength or flux to the stator. An integral constant velocity linear bearing is used to couple the movable rotor and the fixed position motor shaft. A thrust bearing is actuated to offset the magnetic rotor against the attractive magnetic forces toward the stator. The use of a constant velocity linear bearing allows the motor shaft, radial support bearings, position encoder, cooling fan, and output coupling to remain in a constant position while rotor position is offset.

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Fort Wayne, IN, United States of America

Jerry W Medlin