The rotor, the rotating component of an electric motor or generator, is generally cylindrical. This design facilitates smooth rotation within the stator and maintains a consistent air gap, which minimizes mechanical stress and optimizes magnetic flux distribution.
Square, cubic, or rectangular shapes are unsuitable for rotors due to the mechanical imbalance and increased losses resulting from non-uniform air gaps.
A cylindrical rotor offers enhanced mechanical stability and reduced vibration, thereby improving the machine's efficiency and longevity.