DC motors Basic Parts
The basic parts for DC motors are as follows:
1- Stator
The stator carries the field winding and Poles. The stator together with the rotor constitutes the magnetic circuit or core of the machine. It is a hollow cylinder.
2- Rotor
It carries the armature winding. The armature is the load carrying member. The rotor is cylindrical in shape.
3- Armature Winding
This winding rotates in the magnetic field set up at the stationary winding (Field winding). It is the load carrying member mounted on the rotor. An armature winding is a continuous winding; that is, it has no beginning or end. It is composed of a number of coils in series.
4- Field Winding
This is an exciting system which may be an electrical winding or a permanent magnet and which is located on the stator.
Note: DC Motors are generally classified by how their Armature & Field windings are connected to their DC power supply.
5- Commutator
The coils on the armature are terminated and interconnected through the commutator which comprised of a number of bars or commutator segments which are insulated from each other. The commutator rotates with the rotor and serves to rectify the induced voltage and the current in the armature both of which are A.C.
6- Brushes
These are conducting carbon graphite spring loaded to ride on the commutator and act as interface between the external circuit and the armature winding
7- Poles
The field winding is placed in poles, the number of which is determined by the voltage and current ratings of the machine.
8- Slot/Teeth
For mechanical support, protection from abrasion, and further electrical insulation, non-conducting slot liners are often wedged between the coils and the slot walls. The magnetic material between the slots is called teeth.
9- Motor Housing
The motor housing supports the iron core, the brushes and the bearings.