DC Machines Construction Quiz

DC Machines Construction

• A DC machine is an electromechanical device that converts direct current (DC) electrical energy to mechanical energy or vice versa.
• If the device converts DC electrical energy to mechanical energy, it's a DC motor.
• If it converts mechanical energy to DC electrical energy, it's a DC generator.
• Both motors and generators have similar construction.

Main Parts

• Two major parts are needed:
  • Stator: Houses the field winding.
  • Rotor: The rotating part that turns in a magnetic field.

Other Parts

• Yoke (or Frame): A protective covering around the inner parts of the motor. It also carries the magnetic flux created by the poles.
• Poles and Pole Shoes: Magnetic structures fitted onto the yoke. They have a core and a shoe. The poles and the core are placed together, with pressure.
• Field Winding: Made from copper coils, they're wound around the pole shoes
• Armature: The armature core has slots where the armature windings (copper wire) reside. The windings are distributed uniformly.
• Commutator: A cylindrical structure made of copper segments. Each is insulated by mica to prevent short circuits, allowing current collection from armature conductors.
• Brushes: Carbon or graphite structures that make contact with the commutator; collecting current from the commutator and passing it to the stationary circuit.
• Bearings: Support the rotor shaft. Reducing friction losses in the machine.

Types of Armature Winding

• Wave Winding: Armature coils are connected in series through the commutator segments. The armature winding is divided into two parallel paths, regardless of the number of poles.
• Lap Winding: Armature coils connect in series to the commutator segments, causing a division of the winding into multiple parallel paths, equivalent to the number of poles in the machine.