| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a DC motor which can have an armature made larger while equal in total external diameter to a DC motor employing a frame functioning as a back yoke. <P>SOLUTION: A field magnet 4 in a cylindrical shape is held by a bracket 2 and a bracket 3 with the magnet therebetween from both axial ends, and a magnetic frame is not arranged outside the field magnet 4. Since an external diameter of the armature cannot be secured owing to magnetic saturation or because of the size of a magnetic frame in the presence of the magnetic frame when the external diameter is equal to or smaller than 5 mm, or a small diameter, the DC motor has lower characteristics as compared with arrangement of no magnetic frame. No magnetic frame is used and an armature having a larger external diameter can, therefore, be arranged to obtain high characteristics. <P>COPYRIGHT: (C)2012,JPO&INPIT |
