PERMANENT-MAGNET ROTARY ELECTRIC MACHINE, MANUFACTURING METHOD FOR PERMANENT MAGNET USED IN THE SAME, AND MANUFACTURING METHOD FOR THE PERMANENT-MAGNET ROTARY ELECTRIC MACHINE USING THE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To achieve a permanent-magnet rotary electric machine at low cost which enable reduction of eddy currents and attain high output.;SOLUTION: The permanent magnet is composed of a sintered body 11, obtained by compression molding a mixture of first and second kinds 20 and 30 of powder for magnets, different in contraction factor, and sintering the thus obtained compact. In the compact, the first and second kinds 20 and 30 of powder for magnets are alternately deposited in a predetermined direction. The sintered body 11 contains multiple gap portions 12 each placed in an area where the second kind 30 of powder for magnets, lower in contraction factor, is deposited. The eddy current, produced in the magnet, is divided to multiple paths electrically separated by the gap portions 12. As a result, the electrical resistance with respect to eddy current is enhanced as compared with in permanent magnets constituted of a single magnet, and eddy current is reduced. Since the need for processing slits is obviated, it is possible to accomplish the enhancement of the space factor of the permanent magnet buried in a rotor and the reduction of its cost.;COPYRIGHT: (C)2006,JPO&NCIPI