| 摘要 |
PURPOSE:To improve the torque efficiency of a stepping motor by disposing a magnetic shield plate made of a conductive material between adjacent stator pole teeth of the respective phases, thereby decreasing a leakage magnetic flux which does not contribute to a rotary drive. CONSTITUTION:Stator yokes 14a, 19a are formed in the sectional shape in U-shape, and have axially pectinated pole teeth 15a, 20a arranged on the inner peripheral regions in the circumferential direction. The yokes 14b, 19b form a closed magnetic path together with stator yokes 14a, 19a, and have pectinated pole teeth 15b, 20b. A magnetic shield plate 16 made of a conductive material is disposed at both sides adjacent to the poles 15a, 20a of the teeth 15b, 20b. Annular stator coils 17, 21 are also disposed between the yokes 14a, 14b and 19a, 19b. |
