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Recently, a variety of high-performance magnets have appeared in the market, and they are used in various ways. Thus, it is required to evaluate magnets under the conditions suitable to their applications. At first, Chapter 2 of this report clarifies the methods of magnetizing magnets partially and evaluating their flux losses at elevated temperatures. Subsequently, the flux losses were examined by some members of the committee and the results are described in Chapters 3 and 4. The evaluations were carried out for four kinds of Nd-Fe-B-based sintered magnets with different coercivity values and for four kinds of isotropic resin-bonded magnets prepared from different Nd-Fe-B-based powders. The magnets for the evaluations were supplied from Japanese magnet-production companies, and they were magnetized by the method described in Chapter2 so that their flux values were controlled at 100, 75, and 50% of those for the fully magnetized magnets. The sintered magnets were exposed at 100, 150, and 200 ºC, and the resin-bonded magnets were at 50, 75, and 100 ºC. Furthermore, microstructures of the magnets after evaluation are also reported in Chapter 5.
Because of appearance of a variety of high-performance magnets, they are applied to a variety of machines and devices. In this report, applications to micro-machines (Chapter 6), small motors (Chapter 8), large motors (Chapter 9), and automobiles (Chapter 10) are described. In addition, a three dimensional field analysis method for permanent magnet motors is reported in Chapter 7. |
