| 摘要 |
An electric motor having a pancake construction stator and rotor poles that are formed by photolithography. The stator and rotor can be formed from an amorphous material, thereby reducing grain boundaries and allowing smaller poles to be etched. The number of poles, never less than three, can be from 20 to 5000 times the stator diameter in centimeters. The extremely thin rotor comprises a flexible disk spaced from the stator by an air cushion maintained in accordance with forces as dictated by Bernoulli's principle. This insures that the spacing between the rotor and stator is automatically adjusted to minimize the distance between the rotor and stator poles and thereby to maximize flux linkage between the poles. By operating the motor in a range that avoids saturation of the poles, a variable torque motor is provided since increased current through the motor windings allows the magnetic field intensity and thus the flux linkage to increase. Furthermore, by varying the frequency at which the stator windings are fired, the speed of rotation of the rotor can be adjusted. Since an amorphous material such as METGLAS displays high coercivity, rapid changes in frequency can be achieved and rapid switching maintained to insure application of power only during periods of maximum torque. The motor further includes detector windings that monitor magnetic coupling between certain stator poles and the rotor poles, magnetic flux being produced in the certain stator poles by means of a high frequency signal winding. The detector windings comprise four windings capable of monitoring the exact position of the rotor poles of a six phase motor, for purposes of controlling the firing of the phases.
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