| 摘要 |
In order to be able to use magnetostrictive alloys effectively in principally vibration applications an effective magnetic circuit is required. On account of the resistive losses in coils the magnetic working point should be achieved with permanent magnets. In order to re- magnetize permanent magnets a lot of energy is required and as the relative permeability (outside the casing area) is low it is difficult to direct a varying superpositioned flow through permanent magnets. The solution is instead to have two magnetic circuits, one for static flow caused by permanent magnets and a magnetic circuit which is delimited by permanent magnets for the varying magnetic flow caused by coils. The coils are configured so that a positive flow through the coils causes an increase in the magnetic flow in one magnetostrictive rod and a reduction in the flow in the other rod. Depending upon whether the rods are of the same (both positive or negative) magnetostriction or different (one positive, one negative), different kinds of movement can be obtained. <IMAGE> |
