| 摘要 |
<p>PURPOSE:To facilitate the positioning of a permanent magnet and increase the fittability by fitting the permanent magnet to an exciting part or a closed magnetic circuit forming part by magnetic force, and sliding the permanent magnet after that until its periphery touches a protrusion to perform the positioning. CONSTITUTION:A closed magnetic circuit forming part 12 forms a closed magnetic circuit by closing the magnetic flux which an exciting part 11 generates upon the electrification of a primary coil 5, and has almost U-shaped construction. And, surfaces 12a, 12b facing each other hold both ends of the exciting part 11 between. The magnetic poles of a permanent magnet 13 are put between the first magnet joining plane 11a of the exciting part 11 and the second magnet joining plane 12a of the closed magnetic circuit forming part 12, so as to repel the magnetic flux generated by the excitation of the exciting part 11. An encapsulant 23 covering the periphery of the closed magnetic circuit forming part 12 has a protrusion 24 for positioning the permanent magnet 13, in the periphery of the second magnet joining plane 12a. Positioning is finished by fitting the permanent magnet 13 to the second magnet joining plane 12a of the closed magnetic circuit forming part 12 by magnetic force, applying force in the direction of an arrow B, sliding the magnet 13, and bringing it into contact with the protrusion 24.</p> |
