| 摘要 |
<p>PURPOSE:To efficiently obtain a desired magnetic field by forming suitable number of grooves on a permanent magnet as a core of magnetic field generator, thereby effectively suppressing the generation of an eddy current in the magnet. CONSTITUTION:3 grooves 5 are formed on a permanent magnet 4a in such a manner that 2 and 1 are divided on a pair of sides (s), (s) and formed along the lateral direction (w) perpendicular to the longitudinal direction l to extend in the height direction (h) of a permanent magnet 4 to cross the side E. The forming positions of the grooves 5 are set so that the opposite side groove 5 is formed at the intermediate of the 2 grooves 5, 5 of one side, i.e., the grooves are alternately projected at an equal interval from both sides. When the grooves 5 are thus formed on the magnet 4a, the passage of an eddy current (r) generated when a lead 5 is energized is formed by avoiding the grooves 5. Accordingly, the entire length is extended as compared with the case that no groove 5 is formed. Thus, the loss due to the eddy current is reduced to obtain an efficient magnetic field generating effect.</p> |
