THE ARMATURE FRAME 



69 



Fig. 73 is a similar frame, but made in two exactly similar 

 halves drawn together by bolts. 



Fig. 74 shows a light grid construction of frame suitable for 

 induction motors and small alternators. It leaves the exterior of 

 the laminated core well exposed to the air, and is thus excellent 

 from the standpoint of the thermal design. The end flanges are 

 retained by circumferential keys, as shown. 





FIG. 66. Casting for Frame of Stationary Armature. Scott & Mountain. 



