What is the primary function of the brushes in a DC motor?

What is the primary function of the brushes in a DC motor?

• A. Conduce current to the commutator
• B. Provide a magnetic field
• C. Transfer mechanical power to the shaft
• D. Maintain lubrication

Answer: (A)

The primary function of the brushes is to make and carry electrical contact from the stationary power supply to the rotating armature via the commutator. They press against the commutator as the rotor turns, delivering current to the individual commutator segments that feed the armature windings. This arrangement allows the current in the windings to be switched at the right times, producing continuous torque in one direction. The field magnets provide the magnetic field, not the brushes. Brushes are typically carbon to balance good conductivity with wear resistance and to minimize arcing. They do not transfer mechanical power to the shaft, nor do they control lubrication.

The primary function of the brushes is to make and carry electrical contact from the stationary power supply to the rotating armature via the commutator. They press against the commutator as the rotor turns, delivering current to the individual commutator segments that feed the armature windings. This arrangement allows the current in the windings to be switched at the right times, producing continuous torque in one direction. The field magnets provide the magnetic field, not the brushes. Brushes are typically carbon to balance good conductivity with wear resistance and to minimize arcing. They do not transfer mechanical power to the shaft, nor do they control lubrication.