It is a frame which gives mechanical support and protection to other parts of machines from moisture and dust. it provides a path of low reluctance for the flow of flux.
Poles, pole core and pole shoe
Poles are electromagnet on which filed winding is present around it. poles are laminated to reduced eddy current loss. Pole shoe is an extended part of the pole due to which more flux can pass through the air gap to armature winding.
The winding around poles or core is called field winding. Current is passed through the field winding to magnet he tics the poles & poles thee. Due to the flow of current through the field winding alternate N & S poles are produced. It is also called exciting winding.
Armature core is cylindrical drum mounted on the shaft with a large number of slots all over its periphery. All slots are parallel to shaft axis.
Armature conductors are placed in these slots. The core is laminated to reduced eddy current losses and holes are provided on armature core for its cooling.
Armature winding is present in slots. All armature conductors are interconnected to form armature winding and this winding is rotated with the help of prime mover.
The commutator is cylindrical drum mounted on the shaft along with armature core. It consists of segments of copper separated by mica.
Brushes & bearings
The function is to collect current from commutator.It is made up of carbon or graphite having rectangular shape. It is present on the surface of commutator.