190 



ARMATURE CONSTRUCTION 



Type g should only be used when the armature is built in 

 two or more sections, as, if it is in one piece, the rotating field 

 cannot be withdrawn owing to its fouling the lowest range of 

 coils. 



(2) For rotating armatures, any one except g is permissible; 

 but here also it is desirable to keep the coils well back, and to 



One : range. 



c d 



Two -range. 



e f 



Three-range. 

 FIG. 230. Section through Ends of Armature Coils. 



9 



strap them on to the core end plates for security. Thus b, d, e, 

 and / will be preferable. 



(3) For induction motors, the windings of the stator and rotor 

 should come as near together as practicable to render the magnetic 

 leakage a minimum. Thus a, c, and / will be preferable ; and y 

 may also be used for large motors, provided the rotor end windings 

 (whether coils or squirrel cage) do not come in the way of the 

 lowest range. 



In either a, c,/, or g there is the danger, should anything on 

 the rotor become loose and fly out. or anything get between the 



