Methods and apparatus for improved DC motors and magnetic clutches
AssigneeQuantum Corporation
InventorsAlbert L. W. Hartman, Wendy L. Lorimer
Life of this patent
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Abstract
A method for manufacturing a direct current motor having a stator and a rotor. The stator has a first number of slots, and the rotor includes a permanent magnet having a second number of alternately magnetized poles. The method includes calculating a magnetization pattern based on a magnetizing construct associated with said direct current motor, which magnetizing construct includes a hypothetical magnetizing stator having the same number of magnetizing teeth as the second number of alternately magnetized poles. The method further includes having the permanent magnet magnetized with substantially the calculated magnetization pattern, thereby forming the direct current motor.
Claims20
A method for manufacturing a direct current motor having a stator and a rotor, said stator having a first number of slots, comprising:
- providing on a rotor a cylindrical permanent magnet with a second number of alternately magnetized poles and providing transition regions between the alternately magnetized poles in the cylindrical permanent magnet with a magnetization pattern based on a magnetizing construct associated with said direct current motor, said magnetizing construct including a hypothetical magnetizing stator having the same number of magnetizing teeth as said second number of alternately magnetized poles to magnetize said permanent magnet, such that the alternately magnetized poles are magnetized with radial flux lines and wherein the transition regions have flux lines proximate a central portion of the transition regions which are substantially circumferential in orientation near an inner circumferential wall portion of the permanent magnet adjacently facing the stator and flux lines proximate circumferential edge portions of the transition regions adjacent the alternately magnetized poles;
- which are substantially radial in orientation between the inner circumferential wall portion and an outer circumferential wall portion of the permanent magnet away from the stator, such that a radial to circumferential to radial flux line orientation gradient exists within each transition region;
- and
- forming said direct current motor with said permanent magnet within said rotor thereof.
A direct current motor, comprising:
- a stator having a first number of slots;
- and
- a rotor, including
- a permanent magnet having thereon a magnetization pattern with magnetization lines uniquely matched to a geometry of said direct current motor and a number of poles of said permanent magnet, said magnetization pattern in said permanent magnet having alternately magnetized poles magnetized with radial flux lines and having a magnetic transition region between adjacent poles of said magnet, the transition region having flux lines proximate a central portion of the transition region which are substantially circumferential in orientation at an inner wall portion of said magnet adjacently facing the stator and having flux lines proximate circumferential edge portions adjacent the alternately magnetized poles which are substantially radial in orientation at between the inner wall portion and an outer wall portion of said magnet away from the stator, such that a radial to circumferential to radial flux line orientation gradient exists within the transition region.
A method for forming a permanent magnet configured for use in a direct current motor having a stator and a rotor, said stator having a first number of slots comprising:
- providing a permanent magnet having a second number of alternately magnetized poles on a rotor;
- providing said permanent magnet in its unmagnetized state;
- providing a magnetization pattern, said magnetization pattern defining alternately magnetized poles having radial flux lines and having a magnetic transition region between adjacent poles of said magnetization pattern defining substantially circumferential flux lines to be located at a central portion of the transition region near an inner wall portion of said permanent magnet adjacently facing the stator and defining substantially radial flux lines between the inner wall portion and an outer wall portion of said permanent magnet oppositely away from the stator, the substantially radial flux lines to be located at edge portions of the transition region adjacent the alternately magnetized poles, such that the magnetization pattern defines a radial to circumferential to radial flux line orientation gradient within the magnetic transition region;
- and
- magnetizing, using a magnetizing fixture, said permanent magnet with substantially said magnetization pattern.
Dependencies are inferred from the claim text.