The rapid expansion of CNC machines in industry has lead to the need of special motors, capable of delivery high torque values and also to allow rapid variation of rotational speed. The answer was offered by the  spindle motor together with the spindle drive. While the spindle motor  offer a very low rotor inertia and high-peak-torque capability, its companion, the spindle drive allow the access to all motor benefits, implementing specific control techniques to get higher acceleration rates and also high torque values.