YOKES FOR DYNAMO ELECTRIC MACHINES

摘要

A method of manufacturing a yoke for a dynamo electric machine wherein a transversely divided two-part mandrel is inserted into a hollow ferromagnetic sleeve of wall thickness and diameter equal to that of the required yoke. The mandrel defines the shape of the poles to be produced on the yoke and a plurality of punches are driven radially inwardly towards the yoke to deform the material of the sleeve into the dies defined by the recesses of the punches.