To make it possible to obtain large vibrations in an armature for flat type coreless eccentric vibration by arranging three pieces of armature coil groups respectively varying in phases in superposition by offsetting the phases in a circumferential direction in such a manner that a three-phase arrangement is attained and forming an eccentric shape which is not a regular circular planar shape when viewed from an axial direction.
The armature 6-1 for flat type coreless eccentric vibration is arranged with the three armature coil groups 3-1,..., 3-3 respectively varying in phases in superposition by offsetting the phases in the circumferential direction in such a manner that the three-phase arrangement is attained and forming the eccentric shape which is not the regular circular planar shape when viewed from the axial direction. More specifically, the two armature coil groups 3-1 and 3-3 are adjacently arranged and the armature coil 3-2 is arranged in superposition in an intermediate position of the armature coil groups 3-1 and 3-3. If the device is formed in the manner described above, effective conductive parts 3a and 3a' contributing to the torque generated in respective one of the armature coil groups 3-1 and 3-3 exist in the position facing the armature coil 3-2 and, therefore, the large torque is generated in a centroid position and the large vibration is obtained.
MIYAO OSAMI
KOMIYA SOTA
HIRATSUKA YASUNOBU
