Motor armature and method of formation

摘要

A motor armature which facilitates assembly and miniaturisation, comprises an inner cylinder 1 coaxial with an outer cylinder 2 and a plurality of pole pieces 3 provided radially at equal intervals between the inner cylinder 1 and the outer cylinder 2. The inner cylinder 1 is formed into a cylindrical shape by bending in the longitudinal direction a hoop member (band steel) made of a magnetic material and having a predetermined thickness and length. The outer cylinder 2 is made of the hoop member similarly to the inner cylinder 1. Each pole piece 3 comprises a coil 4 wound around a wire piece 5 obtained by cutting a wire (wire rod) made of a magnetic material and having a predetermined thickness and length, one end of the wire piece 5 being fixed to the outer peripheral face of the inner cylinder 1 by means of welding and the other end of the wire piece being fixed to the inner peripheral face of the outer cylinder 2.