4 ARMATURE CONSTRUCTION 







in this case the inner ring is an integral part of the armature 

 and commutator spider. The armature core, C, is formed of 

 " core plates " or " armature laminations " of sheet steel. Some- 

 times the armature is built up on the shaft, but often, as in 

 Fig. 3, the shaft is pressed into the hub of the completed armature. 



FlG. 4. Stationary Armature of Alternating Cum-nt Motor. Srutl A: Mountain. 



For the sake of uniformity, the shaft will not be considered as 

 part of the armature. 



In Fig. 4 is given an instance of the frame and core of 

 an external stationary armature or *' stator." But stators are 

 not necessarily armatures. In the case of continuous-current 

 dynamo-electric machines, the stator is generally the field, and. 



