SERVICING DC (DC) MOTORS

Servicing DC motors has some key features that differ from servicing AC motors, for example. These differences stem from the different design of the motor. Some of the main highlights:

  1. Engine structure and components
  • In addition to the stator winding and rotor winding, DC motors have a commutator and brushes used to transfer current to the rotor winding. This makes DC motors more sensitive to wear on these components.
  • Servicing a DC motor often involves replacing the brushes, cleaning the commutator (especially removing carbon debris from the brushes and milling the insulation between the blades), as well as checking the condition of the commutator (ovality) and the rotor. Sometimes it is also necessary to rebuild the commutator if it is damaged.
  1. Preventing and correcting brush problems
  • Brushes in DC motors wear out over time, which can lead to motor malfunction, increased temperature conditions and noise. Servicing DC motors involves regularly checking the condition of the brushes and commutator, as their wear affects the reliability of the motor. They are replaced with new ones as part of the servicing process at the Matris Service Centre.
  1. Commutator replacement and maintenance
  • The commutator in a DC motor is a key component as it ensures the current is transferred to the rotor. Over time, damage (such as bulges, wear or damage grooves) can occur on the commutator, which can cause a break between the blades.
  • A damaged commutator is usually turned to obtain a new surface and an accurate ovality.
  1. Heating and cooling
  • As DC motors are forced-cooled, it is important to check the cleanliness of the filters regularly, as otherwise debris from the surrounding area will enter the motor.
  1. Maintenance and lifetime
  • DC motors require more maintenance due to wear and tear on the brushes and commutator. This can reduce their lifetime compared to AC motors, which often have a longer lifetime with minimal maintenance, but on the other hand provide more torque even at low speeds.
  1. Ensuring efficiency
  • For DC motors, it is also important to align the commutator correctly to the stator, otherwise the power output of the motor will be reduced.

Some key differences compared to more common AC motor servicing:

  • The commutator and brushes in DC motors need more attention in servicing than AC motors.
  • Checking and servicing the commutator is an important part of servicing DC motors.
  • Brushes need to be replaced because they wear out with use.