| 摘要 |
PURPOSE:To improve the thrust force of a movable element and to eliminate a frictional load of a stator and the element due to its attracting force by providing a magnetic field generating auxiliary coil together with a permanent magnet at the element oppositely to the magnet, and forming the stator of a nonmagnetic material. CONSTITUTION:An auxiliary coil 1 is disposed continuously along a longitudinal direction on the surface of a yoke 68 opposed face-to-face to a permanent magnet 62 to be secured. When a current of a direction of an arrow flows in the coil 1, a magnetic path designated by an arrow is formed between the adjacent coil 1 and the yoke 68. Since it passes the same magnetic path as that of a magnetic flux generated from the magnet 62, a magnetic flux which passes an air gap between the coil 1 and a stator bracket 65 becomes the sum of both. Since a thrust force is proportional to a magnetic flux density, it further increases. Since the stator is formed of a nonmagnetic material, it will not be attracted by the movable element. This eliminates the variation in the motor characteristics due to the deformation of the stator and no frictional load appears. Accordingly, the wear of a slide section, such as rollers, bearings due to the frictional load can be eliminated.
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