Methods for producing dynamo-electric machine armatures with improved balance

A method for producing an armature for a dynamo-electric machine, said armature having a central longitudinal shaft, a substantially cylindrical core mounted substantially concentrically on said shaft, and a plurality of coils of wire wound on said core, said coils of wire being made up of turns of wire which are substantially disposed in planes that are substantially parallel to but radially spaced from the central longitudinal axis of said shaft, said method comprising the steps of:

• measuring any initial unbalance of said armature about said central longitudinal axis prior to winding at least some of said coils;
• and
• winding at least one of said coils after performing said measuring step with a number of turns of wire that is selected to unbalance said coils about said central longitudinal axis so that the unbalance of said coils at least partly cancels said initial unbalance, wherein said measuring step comprises the steps of:
• measuring the magnitude of said initial unbalance;
• and
• determining the radial direction of said initial unbalance, and wherein said winding step comprises the step of:
• winding a first coil which has turns of wire substantially disposed in a first plane that is radially spaced from said central longitudinal axis in a direction opposite to said radial direction with a greater number of turns of wire than a second coil which has turns of wire substantially disposed in a second plane that is substantially parallel to said first plane but radially spaced from said central longitudinal axis in said radial direction.