Minebea Mitsumi Inc.

Minebea Company, Limited

Shiho Ohya

Osamu Yamada

Fumitoshi Yamashita

Akihiro Yamane

Susumu Teraoka

Yu Okawara

Toshinori Suzuki

A rare earth bonded magnet comprises a rare earth-iron-based magnetic powder and a thermosetting resin composition. The thermosetting resin composition is obtained by blending a dicyclopentadiene type epoxy resin as a base resin and dicyandiamide as a curing agent. The dicyclopentadiene type epoxy resin includes a predetermined structure wherein an average value of a repeating unit n is 1 to 3.

Rare earth bonded magnet

A motor includes poles P having a remanence Mr of 0.9 T or more, a coercivity HcJ of 0.80 MA/m or more, and a maximum energy product (BH)of 150 kJ/mor more, which sets a center point Pc of the magnetic poles in a circumferential direction on a rotor outer circumferential surface to a maximum thickness t, wherein when a line connecting the Pc and a rotational axis center Rc is Pc-Rc, a straight line connecting an arbitrary point Px in the circumferential direction on the rotor outer circumferential surface and the Rc is Px-Rc, an apex angle of the lines Pc-Rc and Px-Rc is &#x3b8;, a number of pole pairs is Pn, a circumferential direction magnetic pole end is Pe, and a magnetic pole end biasing distance &#x394;Lof the circumferential direction magnetic pole ends Pe is &#x3b1;&#xd7;t(&#x3b1; is a coefficient).

Inner rotor-type permanent magnet motor with annular magnetic poles

Anisotropic rare earth-iron based resin bonded magnet comprises: [1] a continuous phase including: (1) a spherical SmFeNbased magnetic material covered with epoxy oligomer where its average particle size is 1 to 10 &#x3bc;m, its average aspect ratio ARis 0.8 or more, and mechanical milling is not applied after Sm&#x2014;Fe alloy is nitrided; (2) a linear polymer with active hydrogen group reacting to the oligomer; and (3) additive; and [2] a discontinuous phase being an NdFeB based magnetic material coated with the epoxy oligomer where its average particle size is 50 to 150 &#x3bc;m, and its average aspect ratio ARis 0.65 or more, further satisfying: [3] the air-gap ratio of a granular compound on the phases is 5% or less; and [4] a composition where crosslinking agent with 10 &#x3bc;m or less is adhered on the granular compound is formed at 50 MPa or less.

Anisotropic rare earth-iron based resin bonded magnet

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Kitasaku-gun, Japan

Shiho Ohya