Studies on Flux Controlling Method with Convergence and Divergence (Magnetic flux lens)

点击翻译按钮获取中文摘要

To develop control elements in controlling magnetic flux, this study have been curried out for the use of flux convergence and divergence. The summary of the results is shown below.(1)Alternating magnetic fluxWe showed that it is possible to obtain convex and concave lens effect for alternating flux by using the eddy current effect. When a conductive plate with a central hole and one slit is placed in alternating magnetic field, the flux is concentrated in the hole(convex lens effect). In the case of the plate without slit, we can obtain the concave lens effect. The convex lens effect is very useful in generating a high magnetic field, and the concave lens effect can be applied to magnetic shielding.(2)DC magnetic fluxIn the case of dc magnetic field, it is possible to obtain the same effects above by using the permanent magnet. Combining a electromagnet and plural permanent magnet with high coercive force, the magnetic field can be designed. We have found that the exciting current value can reduce in the electromagnet covered by permanent magnets.(3)Switching of magnetic circuitThere are two kinds of permanent magnet which is used in electrical machinery and apparatus. The one is the alnico type magnets that the coercive force is small and the remanent flux density is large. The other is the ferrite type magnets that the coercive force is large and the residual magnetization is small. We developed a switching system of magnetic circuit by the combination of the different type magnets. Changing the magnetizing direction of the alnico type magnet, the flow of flux line can be controlled easily. This switching system has a wide application in the lifting magnet, the high magnetic field generator, and the electromagnetic brakes.