| 摘要 |
<p>PURPOSE: To easily assemble and to eliminate bad influence for a magnetic field by providing an individual recessed part for positioning and holding in relation to a displacement intersecting a magnetic axis of a permanent magnet. CONSTITUTION: Two intersecting members 75 and 77 which closely contact to the inner surface of an external pole piece part 29 have hooks 78 and 80, respectively, and they snap-fixes a cage 60 to the internal flat surface of the external pole piece part 29 in cooperation with individual recessed/depressed parts 63 and 64 of a pole piece 61. All of the external pole piece part 29, a magnet 17 and an internal pole piece 16 have the same width as a free space between side walls 73 and 74, and the pole pieces 29 and 16 are held with the attracting force of the magnet 17. Thereby mechanical fixing is performed accurately and easily, and a magnetic flux is not affected.</p> |
