| 摘要 |
PURPOSE:To increase attraction force of an electromagnet having poles when energized by constituting the electromagnet such that both end portions of an armature having a piece of the pole whose only one end protrudes are positioned at the pole portions formed in specified shape, respectively. CONSTITUTION:A permanent magnet 5 is clamped by pieces of magnetic poles 4 and 4 to form an armature 2 which rotates around a rotation shaft 6. One of the pieces protrudes at its one end portion beyond the length of the permanent magnet 5. A core 1 is provided with U-shaped and about J-shaped magnetic pole portions 1a and 1b its both end portions. The end portions of the armature 2 are positioned in the poles. The protruding magnetic pole 4 is positioned in the J-shaped magnetic pole portion 1b. When the armature 2 rotates in the direction depicted by an arrow, a gap g' and the magnetic resistance is reduced and the magnetic flux density is increased. Thus, attraction force of an electro- magnet is increased when energized. |
