Patent ID: 7576467

Claim:
An armature formed by winding coils around laminated cores and bending the laminated cores in an annular shape, comprising: a plurality of core back parts circularly arranged to form an annular core back, each of the core back part having a tooth projecting toward a center of the annular core back; coupling portions of the core back, which couple the core back parts neighboring in a circumferential direction of the annular core back and yield at the time of bending; a plurality of insulators, each of the insulator attached to each of the core back part to cover an inner peripheral face of the core back part and a surface of the tooth, and made of an electrically insulating material; and coils formed by continually winding a conductor around the teeth over the insulators, the conductor extending at radially inner positions to the coupling portion of the core back; wherein: a side edge in the circumferential direction of the insulator is positioned closely to a neighboring insulator forming a gap; and a diameter of the conductor measured perpendicular to a longitudinal direction thereof is greater than a width of the gap.