MAGNET ROLL AND MANUFACTURE OF THE SAME

摘要

PURPOSE:To reduce the variation width of the discrepancy from the angular position of the peak of a surface magnetic field by a method wherein resin or rubber magnets which are formed by extrusion and have O-shaped or C- shaped cross sections are bonded to the shaft of a polygonal or protruding or recessed cross section. CONSTITUTION:A magnet roll is composed of a shaft of a square cross section and magnets 12a and 12b which have practically C-shaped cross sections and bonded around the shaft 11 with adhesive. The resin or rubber magnet which has practically O-shaped or C-shaped cross section may be isotropic or anisotropic. However, in order to select arbitrary number of poles while maintaining the surface magnetic field high, the polarity-anisotropic magnet is preferred. Further, although the number of the C-shaped cross section magnets is not specifically limited, it is preferable to reduce the number of the magnets by bonding two magnets to each other so as to hold the shaft between them.