Armature structures and methods that provide very dense coil windings and afford very rapid winding methods at a relatively low cost. The first magnet and the second magnet generate a cross magnetic field whose strength in a spacing direction, which is orthogonal to a conveying direction, is within a predetermined range. The gasket comprises a plurality of ribs arranged along a radial direction. A first fitting portion is formed on a connected surface of the connector to be connected with the second body. The second threshold value is lower than the first threshold value.