Tdk Corporation

Motohisa Murata

Nobuo Takagi

Koji Mitake

Kazuo Sato

Kazuya Sakamoto

Tetsuya Hidaka

Shinya Fujito

Motoaki Hosako

In a magnet stack, an eddy current channel is cut off by an insulating layer in an insulating region of facing surface regions of the pair of magnets. Meanwhile, in a conducting region of the facing surface region of the pair of magnets, electrons can move between the pair of magnets via a conductor, and heat can be exchanged between the pair of magnets by the movement of electrons. Therefore, in the magnet stack, by cutting off the eddy current channel in the insulating region of the facing surface region of the pair of magnets, the degradation in magnet performance is suppressed and the cooling efficiency of the magnet is enhanced in the conducting region.

Magnet stack and motor

In a magnet, an insulating layer is fixed to an upper surface of the magnet provided with the insulating layer, but is not fixed to a lower surface of the magnet above the insulating layer. Therefore, even when the magnet expands or contracts due to a temperature change, stress is less likely to occur at an interface between the insulating layer provided on the upper surface of the magnet and the magnet above the insulating layer.

Magnet, magnet stack, and motor

A sintered rare earth magnet rotating machine and method improve temperature properties and strength having an excellent corrosion resistance. The sintered rare earth magnet includes at least a main phase composed of RTB (R represents at least one rare earth element of Nd, Pr or both and T represents at least one transition metal element including Fe or Fe and Co) compound and a grain boundary phase containing a higher proportion of R than the main phase, wherein the main phase includes a heavy rare earth element (one of Dy, Tb or both), at least part of main phase grains of the main phase included in the sintered rare earth magnet includes at least the following regions, low, high and intermediate concentration regions. These regions exist in order of low, high, and intermediate concentration regions, from low concentration region towards the grain boundary phase in the main phase grains.

Sintered rare earth magnet, method of producing the same, and rotating machine

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Tokyo, Japan

Motohisa Murata