In order the step motor null which uses the moving magnet type instrument and the magnetic rotor which use the magnetic rotor and

摘要

PROBLEM TO BE SOLVED: To provide a magnet rotor improved in magnetic characteristics, a movable magnet type instrument using the magnet rotor, and a stepping motor using the magnet rotor, while suppressing the lowering of a magnetic force by taking account shapes of ring-shaped magnets that constitute the magnet rotor, the shape of a molded rotor body and positions of magnetic poles to be magnetized.;SOLUTION: The magnet rotor is constituted such that: whirl-stop protrusions 11 formed into almost rectangular shapes are protrusively formed at prescribed intervals on internal peripheral walls of hollows of the ring-shaped plastic magnets 10; the rotor body 20 composed of a plastic material is filling-molded by injection molding copying to the shape of the whirl-stop protrusion 11; and the magnetic poles 1 are magnetized so that the position of a boundary 2 between the adjacent magnetic poles 1 almost coincides with the position of the whirl-stop protrusion 11.;COPYRIGHT: (C)2006,JPO&NCIPI