Construction of DC Machines

Construction of DC Machines

It consists of

1.     Stator (Stationary part)

2.     Rotor (Rotating part)

Stator

          The stator of the dc machine has poles, which are excited by either dc current or  permanent magnets to produce magnetic fields.

In the neutral zone, in t he middle between the poles, commutating poles are placed to reduce sparking of the commutator.

Compensating windings are mounted on the main poles. These reduce flux weakening commutation problems.

The poles are mounted o n an iron core that provides a closed magnetic circuit.

Rotor

          The rotor has a ring-shaped laminated iron core with slots.

Coils with several turns are placed in the slots. The distance between the two legs of the coil is about 180 electric degrees.

The rotor coils are connected in series through the commutator segments.

The ends of each coil are connected to a commutator segment.

The commutator consists of insulated copper segments mounted on an insulated tube.

Two brushes are pressed to the commutator to permit current flow and they are placed in neutral zone.