Manufacturing method of rare earth-iron ring magnet with continuous orientation controlled anisotropy

Abstract

The essential processes of this method include: a process for manufacturing segments, an anisotropic direction of which is continuously changed from a direction perpendicular to a surface to inside the surface by a uniform magnetic field maintained in a constant direction; and a process for arranging a plurality of the segments on a circumference, extruding the segments in a ring shape by rheology based on viscous deformation of the segments from one thrust direction end surface of the segments, and compressing the segments from both end surfaces in the thrust direction of the segments. In a ring magnet in which the anisotropic orientation is continuously controlled, the generation source of the static magnetic field has an energy density (BH) max >= 160 to 180 kJ / m<3>.

Description

technical field [0001] The present invention relates to a rare earth-iron having a radially anisotropic region at the center of a magnetic pole and a non-radial magnetically anisotropic region between magnetic poles, which does not degrade magnetic properties even when formed into a small diameter. A method of manufacturing a quasi-ring magnet. More specifically, the present invention relates to a method for manufacturing a rare-earth-iron-based ring magnet with continuously controlled anisotropy direction, which is widely used as a home appliance, an air conditioner, etc. High-performance permanent magnet motors that have a major impact on power saving, energy saving, miniaturization, and quietness of magnet-type motors of about 50W or less for various drive sources such as equipment and information equipment. Background technique [0002] The motor is regarded as a kind of rotor, shaft, bearing, stator, etc. manufactured by high-precision machining of various materials su...

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Problems solved by technology

Therefore, using Figure 11A , Figure 11B and Figure 11C The shown prior art cogging torque reduction method suffers from the problem of sacrificing the increase in the torque density of the motor due to the increase in the energy density (BH)max of the magnet

That is, since 1985, R.W.Lee et al. used energy density (BH)max as 111kJ / m 3 The strip fabrication energy density (BH)max is 72kJ / m 3 The isotropic Nd of 2 Fe 14 Although more than 20 years have passed since Class B bonded magnets, the progress in energy density (BH)max is less than 10kJ / m 3

However, the opposite will result in increased cogging torque

Moreover, as far as the existing radially anisotropic ring magnet is concerned, when its inner and outer diameters are reduced, even if the core of the ring cavity (ring cavity) is made to repel the external magnetic field Hex to generate a radially oriented magnetic field, due to its magnetic flux leakage The increase of the amount will also lead to the deterioration of the reduction degree of the energy density (BH)max

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