| 摘要 |
<p>PROBLEM TO BE SOLVED: To allow simple mounting works for an armature on a hub and permit the armature to rotate integrally with the hub while a sufficient strength is secured. SOLUTION: A yoke assembly is structured so that an electromagnetic coil is installed at a cylindrical part of a bobbin in a yoke. A rotary shaft is inserted rotatably in the cylindrical part of the bobbin, and a rotor is fitted on the shaft in such a way as rotatable integrally with the shaft. A hub 40 is rotatably fitted on the shaft on its side opposite the electromagnetic coil with the rotor interposed. A cylindrical extension part 40b is provided at the opening edge of the center hole 40a in the hub 40 side face confronting the rotor. An armature 42 is fitted on the extension part 40b in the condition that it is in convex- concave fitting with the extension part 40b in such a way as not rotatable with respect to the hub 40 and movable in the longitudinal direction of the extension part 40b (by key 42b and key seat 46) and is energized toward the hub 40 at all times by a leaf spring 44 attached in engagement to the extension part 40b.</p> |
