| 摘要 |
<p>PURPOSE:To contrive improvement in magnetic efficiency by increasing the distance between magnetic poles of a permanent magnet by a method wherein the first pole piece of the permanent magnet is positioned between the two branches of a bifurcated magnetic pole part, and the second pole piece is positioned outside a pair of external yokes. CONSTITUTION:A pair of external yokes 3 and 4, the base end part of which is connected to the other end part of a center yoke 2 and the tip part is arranged outside the direction of opening of a bifurcated magnetic pole part 1, and the bifurcated magnetic pole part 1 are provided. Also, the permanent magnet 8, which retains the first pole piece 5 positioned between the forks of the bifurcated pole part 1 arranged in a freely reciprocating manner in the direction of the row of above-mentioned parts, also retains the second pole pieces 6 and 7 positioned outside the tip part of a pair of external yokes 3 and 4, and magnetized in such a manner that the different magnetic poles N and S are given to the first pole piece 5 and the second pole pieces 6 and 7, is provided. Also, a pair of coils 9 and 10, wound on the outside yokes 3 and 4 respectively, are provided. As a result, the distance between magnetic poles of the permanent magnet 8 can be made longer, and its magnetic efficiency can be improved.</p> |
