Motor dynamic balancing refers to the process of testing and correcting the rotor of a motor under rotation, so as to minimise vibration and noise during operation while ensuring stable performance and longer service life.
When the rotor of a motor spins at high speed, any uneven material distribution, machining tolerance, or assembly imperfection will lead to centrifugal imbalance — generating additional forces that cause vibration and noise. Dynamic balancing testing measures vibration parameters of the rotor (such as displacement, velocity, and acceleration) to determine the unbalance magnitude and phase angle. Corrections are then applied on two balancing planes simultaneously by adding or removing mass at the correct angular position.
Sources show that unbalanced forces are a dominant cause of mechanical vibration in rotating machines.
Vibration analysis: Sensors capture the rotor’s vibration amplitude and frequency during rotation to assess the unbalance severity.
Unbalance mass calculation: Based on vibration data, the required correction mass (in grams) and its angular position are calculated.
Phase correction: The exact angle for adding or removing mass is determined so that vibration amplitude falls within allowable limits.
This aligns with standard dynamic balancing methodologies applied in motor and generator rotors. 
Reduce operating vibration and noise, thereby extending the life of bearings and other rotating components.
Decrease mechanical wear, enhance efficiency, and improve overall motor reliability.
Ensure motor safety and stable performance during high-speed operation or in demanding environments.
For small-diameter motors or applications requiring high rotational speeds and low noise (such as in robotic devices, vacuum cleaners, or medical instruments), even slight rotor imbalance can disproportionately affect performance, noise, and reliability. By implementing a rigorous dynamic balancing procedure, the motor manufacturer can deliver a product with smoother operation, lower vibration signature, and longer service life — key differentiators in the market.
