Self-starting synchronous motor
AssigneeElmeg Elektro-Mechanik GmbH
InventorHans-Werner Reuting
Life of this patent
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Abstract
An electro-magnetic synchronous motor has an E-shaped stator linear or partially wrapped around an axis, the legs being the pole shoes. The middle leg includes a permanent magnet and one or both outer legs have coils. A movable displacement element has poles spaced further apart than the stator poles. The movable element has a stable position for zero energization in which one of its poles aligns with the stator pole having the permanent magnet. Coil energization disturbs magnetic field symmetry to move the element always in the right direction.
Claims20
Electromagnetic motor comprising:
- a stator having three pole shoes, one of which being permanently magnetically biased and a divided magnetic return flux runs through the two other pole shoes;
- a movable element having at least two pole shoes of similar width and being magnetically interconnected to complete separate paths for said divided magnetic flux, the two poles of the movable element being spaced differently than the said three pole shoes are spaced from each other, so that in a symmetrical position of one of the shoes of the element relative to a central one of said stator pole shoes, another of the pole shoes of the element is asymmetrically positioned to each of the other two stator pole shoes, whereby a stable neutral position for the element is defined by a position of any of the pole shoes of the element opposite the biased stator pole shoe, while at least one respective other pole shoe of the movable element returns said divided flux to said two other pole shoes, so that the movable element experiences oppositely directed, balanced driving forces;
- and
- coil means including a coil on or in magnetically coupled relation with one of said other stator pole shoes to provide a flux thereto to modify said forces towards imbalance, so that the element is moved by a distance at least half a spacing between two of the poles of the movable element and towards a position in which the other one of the poles of the elements faces said biased pole shoe.
An electromagnetic stepping motor, comprising:
- a rotor having a plurality of similarly wide and equidistantly spaced salient poles;
- each pole having particular width and the spacing between the poles having particular width;
- a stator being of E-shaped configuration with a permanently biased center pole, having a width corresponding to the width of the rotor poles, and having two outer poles spaced from the center pole at a spacing smaller than the width of the spacing between the rotor poles, and the outer poles having width smaller than the width of the center pole;
- and
- coil means on the stator for asymmetrically modifying the bias in the two outer poles.
Dependencies are inferred from the claim text.