| 摘要 |
<p>PURPOSE:To prevent vibration of an electromagnetic sheet steel dun to an a.c. magnetic field for reducing a noise remarkably by filling a cavity formed by an outside core and inside. core with resin material. CONSTITUTION:The resin material 17 is made by blending as a fillet a hollow inorganic filler which is made of alumina or other substance or magnetic grains such as steel powder, ferrite, etc., into epoxy resin or urethane resin. Cavities 15 are filled with the resin material 17. At the time of filling of the cavities 15, inside cores 11 and 12 and an outside core 14 can be either in the annealed or non-annealed condition. When the cores are in the annealed condition, spacers 16 can be either removed or left over. When filling, one side of each of the cavities is closed. After the resin material is flown into the cavities, it is cured. The resin material 17 blended with the magnetic grains as a filler has a good dispersion of the magnetic grains when it is cured in a d.c. magnetic field. If the magnetic grains are steel powder of 0.5mum or smaller, the steel powder disperses uniformly without separating in the resin material 17.</p> |
