| 摘要 |
PURPOSE:To facilitate manufacturing of a meter and to improve its precision, by composing an internal magnetism type magnetic circuit for the meter of an oval shape powder-sintered permanent magnet having anisotropy in the direction of short axis and a yoke surrounding this magnet. CONSTITUTION:A permanent magnet 1 of an inside core is provided with an oval shape and an anisotropy in the direction of a short axis, and distribution of gap magnetic flux density between the permanent magnet 1 and a yoke 2 surrounding the magnet is evened. As this oval permanent magnet is manufactured into a powder-sintered permanent magnet by powder metallurgy process, it can be formed into an oval shape from the very beginning, and moreover, its characteristics as a magnet is uniform and dimensional accuracy is excellent. Further, the center of the permanent magnet were to be off, the distribution of the gap magnetic flux density and the level remain almost unvaried. |
