JPS5583449A - Motor - Google Patents

Abstract

PURPOSE:To provide a motor of high efficiency by providing magnetic bodies on both sides of a permanent magnet with particular magnetic poles on its both end surfaces, forming gaps between the three, and arranging driving coils in the gaps so that they may surround the poles of the permanent magnet. CONSTITUTION:A permanent magnetic rotor is constructed by fixing, to a rotating shaft 12, a torus permanent magnet 11 in which plural driving field magnetic poles of N and S poles are provided alternately so that the same magnetic poles may correspond on both end surfaces, and disc magnetic bodies 13 and 14 arranged on both sides of the permanent magnet 11 via axial direction gaps so that all of the 11-14 may be turned in one piece. Annular coils 18 formed in hexagonal patterns are bent around the permanent magnet 11 and arranged so that they may position in the gaps between the permanent magnet 11 and the magnetic bodies 13 and 14, and surround the driving field magnetic poles of the same polarity magnetized on the periphery of the permanent magnet 11. By so doing, hysteresis loss and eddy current loss can be reduced, the total coil parts of the annular coils 18 except the inner peripheral parts can contribute to generate torque and thus motor efficiency can be improved.