| 摘要 |
PROBLEM TO BE SOLVED: To secure high-speed responsiveness necessary for a small-sized and thin-diameter stepping motor. SOLUTION: The necessary high-speed responsiveness is secured since the inertia moment of a rotor 2 is reduced by making the outside diameter dimension D<SB>M</SB>of a rotor magnet 3 smaller than the outside diameter dimension D<SB>B</SB>of a coil bobbin 9 in diameter. Necessary motor torque is generated, since the inside diameter D<SB>S</SB>of a cylindrical space S formed of pole teeth 7b, 8b of first and second stator yokes 7, 8 which are alternately engaged with each other is formed smaller than the outside dimension D<SB>B</SB>of the coil bobbin 9 in diameter, so as to accord with the outside diameter dimension D<SB>M</SB>of the rotor magnet 3. Any problem is not caused in assembling each part even if employing a structure in which the pole teeth 7b of the outer yoke are overlapped with the coil bobbin 9 in an axial view as above, since the pole teeth 7b of the outer yoke are formed separate from the housing 6. COPYRIGHT: (C)2008,JPO&INPIT |
