PURPOSE: To reduce the generation of eddy current in a magnetic pole piece due to the drive of an inclined magnetic field coil by forming the magnetic pole piece into a lamination structure and constituting the magnetic pole piece member faced to permanent magnet side from a thick plate magnetic disc and constituting the magnetic pole piece member faced to a gap side from a molded magnetic member consisting of soft magnetic powder and joint-fixing the both members.
CONSTITUTION: Each magnetic pole piece 5a, 5b is formed into a lamination structure in double layer form in the thickness direction, and the first magnetic pole piece member 8 faced to permanent magnets 1a, 1b side and the second magnetic pole piece member 9 faced to a gap A side are joined integrally and fixed. The magnetic pole piece member 8 is constituted of an integrally formed thick plate magnetic disc having a prescribed diameter, and the magnetic pole piece member 9 is molded to a prescribed shape by using the soft magnetic powder, and constituted of a molding magnetic member having an annular projection 4 on the peripheral part. With such constitution, the resistance value of the magnetic pole piece member 9 faced to the gap A side increases, and no eddy current having the same pattern to that of the inclined magnetic field coils 6e and 6b is formed, and the eddy current generated in the magnetic pole pieces 5a and 5b can be reduced.
SATO SHIGERU
AOKI MASAAKI
SUMITOMO SPEC METALS
| JPS6325907A | 1988-02-03 | |||
| JPS63105745A | 1988-05-11 | |||
| JPS63115305A | 1988-05-19 |
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