Magnetically enhanced stepping motor
AssigneeSigma Instruments, Inc.
InventorJohn G. Gamble
Life of this patent
Estimating the term…
Abstract
The electric motor includes a mover, which may be a rotor or actuator, and a stator having a number of poles projecting toward the mover. The poles have soft-magnetic teeth projecting toward the mover and extending transverse to the direction of mover movement, and the mover has soft-magnetic teeth projecting toward the stator teeth and extending transverse to the direction of mover movement. Windings energize the stator to move the mover. Dividing each pole transverse to the direction of mover movement to define two pole portions per pole, and locating permanent magnetic material between stator teeth in only one portion of each of the poles, enhances the motor torque while achieving a saving of permanent magnetic material. Preferably the magnetic material exists on alternate pole portions in successive poles.
Claims20
An electric motor, comprising:
- a stator;
- a mover mounted for movement relative to said stator;
- said stator having a plurality of poles projecting toward said mover;
- said poles each having a plurality of teeth projecting toward said mover, said stator teeth being composed of soft magnetic material;
- said mover having a plurality of mover teeth projecting toward said stator teeth and being composed of soft magnetic material;
- winding means indictively coupled to said poles for magnetically actuating said stator teeth so as to cause magnetic interaction between said mover teeth and said stator teeth and move said mover teeth relative to said stator teeth along a given direction;
- said stator teeth on each of said poles extending in a longitudinal direction and each of said poles being divided transverse to the longitudinal direction into two pole portions,
- one portion of each of said poles having permanent magnetic means extending along at least one tooth for producing a magnetic field poled transverse to said mover, at least one of said poles having said permanent magnetic means in only one of said two pole portions.
Dependencies are inferred from the claim text.