Insulator, armature and dynamo-electric machine

The present invention relates to an insulator 20 to be disposed in an armature core having a plurality of radially-formed salient poles. The insulator 20 comprises a winding aligning portion 22 having an approximately V shape (forming an angle of 60 degrees) and getting narrower from an outer side to an inner side in a radial direction of the armature core approximately at the middle between the salient poles to position a winding disposed at a first layer which is a most inner side in the radial direction of the armature core approximately at a middle between the salient poles. By this structure, it is possible to align the windings on the second layer and beyond, thereby preventing a dig-in and the like of the windings and hence preventing faulty insulation between the windings.