To prevent a pin hole, or recession, or peeling of insulating coating, and enable a thick cable to be used for winding, by providing an armature with a hole in stack direction within the face between the slot of an armature iron core and the rotary shaft insertion hole.
This armature is provided with through holes 1a bored in, for example, four places in stack direction within the face between the slot of its iron core 1 and a rotary shaft insertion hole 4. Accordingly, in case that heat is added in the pretreatment of an electrostatic powder coating process to the armature iron core 1 provided with through holes 1a and the rotary shaft 3, the heat is conducted into the iron core 1 of the armature, too, through the through hole 1a, and the oil in between electromagnetic steel plates or the oil between the rotary shaft 3 inserted into the rotary shaft insertion hole 4 and the iron core 1 of the armature is gasified. Accordingly, the oil removal treatment can be performed enough and quickly, and a pin hole or recession ceases to occur in the insulating coating by electrostatic powder coating material, and the peeling of the insulating coating can be prevented.
OTAKA SHUICHI
YASUJIMA TAKEHIKO
MITSUBISHI ELECTRIC HOME APPL