PURPOSE: To prevent positional shift or lowering of pressing force due to rotation of a commutator by making a groove, in alignment with a coil insertion groove, in the insulated part of a ceramic commutator and providing a corresponding protrusion to be fitted in a guide ring.
CONSTITUTION: When a ceramic commutator 6 is mounted on a shaft 12, a groove (e) is made, in alignment with a coil inserting position, in the insulating part (b) of the ceramic commutator 6. A guide ring 10 having a protrusion (f) to be fitted in the groove (e) is also provided. Since the protrusion (f) of the guide ring 10, to be fitted in the groove (e) in the insulating part (b) of the ceramic commutator 6, is aligned with the coil insertion groove in the core, an armature coil 8 can be connected easily. Furthermore, since the protrusion of the guide ring is fitted in the groove in the insulating part of the ceramic commutator, rotational force can be suppressed sufficiently even when the ceramic commutator is positioned or the shaft 12 is elongated to cause lowering of pressing force and thereby the ceramic commutator can be secured firmly to the shaft.
TAWARA KAZUO
TAKAHASHI NORIYOSHI
CHIBA AKIO
SOFUE MASAHISA
ABUKAWA TOSHIMI
