What is the purpose of bearings in a motor?

• A. Aid in electrical connection to the rotor
• B. Reduce friction by lubrication
• C. Help manage heat in the motor
• D. Support the rotor and allow smooth rotation

Answer: (D)

Bearings provide a controlled, low-friction axis for the rotor, letting it spin freely while staying aligned in the motor housing. They support the shaft, carry radial and axial loads, and keep the rotor from rubbing against the stator, which prevents wear and seizure at speed. Lubrication is how bearings reduce friction and wear and helps carry away some heat, but the primary purpose is to support the rotor and enable smooth rotation. Bearings don’t provide electrical connections to the rotor, and while they influence heat management, that’s a secondary benefit rather than the main role.