Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Itsuo Arima

Hiromichi Horie

Mikio Morita

Kumi Ochiai

Hisato Kamohara

A compressed powder core is made of a compressed body of a magnetic powder each particle of which has a surface covered with an insulating layer. The insulating layer is formed of an insulating material selected from the group consisting of an inorganic compound powder having an electronegativity of not less than 12.5, an inorganic compound powder having an electronegativity of less than 8.5, a metal alkoxide and a decomposition product of a metal alkoxide.

Compressed magnetic powder core

A magnetic powder composition suitable for manufacturing a powder core used in a reactor or transformer connected to a semiconductor switching element, essentially consists of a powder of a soft magnetic metal or alloy or a mixture of these, an electrically insulating binder polymer for binding the powder, and a coupling agent of an organic metallic compound for coupling the powder and the binder polymer. The obtained powder core has excellent frequency characteristics of magnetic permeability, a high magnetic flux density, and a small iron loss at high frequencies.

Magnetic powder composition

An annular core used in a so-called air axial gap motor includes a magnetic and structural gap along the axial direction. By using a compressed molded body of a mixture of a magnetic metal powder and an electrically insulating resin as major constituents, an annular molded body and a molded plate are prepared. The annular molded body has slots and teeth alternately formed along the circumferential direction. The molded plate closes the upper portions of the slots to constitute a fully closed slot structure.

Armature annular core

Disclosed is a process for producing a magnetic core, comprising the first step of bringing magnetic powder of a metal into contact with a polymer dispersion, followed by drying, to form an insulating layer on the surface of the magnetic powder and the second step of compression molding the magnetic powder. Also, disclosed is a magnetic core produced by the above process. A magnetic core according to this invention has, since good insulation between magnetic powder particles can be ensured with a small amount of an insulating material, high magnetic flux density, small core loss and excellent frequency characteristics of magnetic permeability and is particularly suitable for use in high frequency range of some 10 KHz or higher.

Magnetic core and preparation thereof

Disclosed are deflecting yoke for electromagnetic deflection type cathode-ray tubes which comprises a compressively molded products consisting substantially of an iron powder or an iron-based alloy magnetic powder; an electrically insulating powdery resin; an organic metallic coupling agent; and an electrically insulating powdery inorganic compound;

Deflecting yoke for electromagnetic deflection type cathode-ray tubes

Disclosed is an magnetic core comprising a molded product made of an iron powder and/or an iron alloy magnetic powder having a mean particle size of 10 to 100 .mu.m, and 1.5 to 40%, as a total amount in terms of volume ratio, of an insulating binder resin and an insulating inorganic compound powder. Also disclosed is a useful method of producing the magnetic core.

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Kawasaki, Japan

Itsuo Arima