What is the difference between a general motor and a high-speed motor?
The rotational inertia of high speed motor is generally small, so the long type of motor is more.
The bearing of high speed motor is wear-resisting, so some high-speed motor USES liquid bearing or air bearing, so that the rotor does not have direct contact with the stator.
Ordinary ac motor is restricted by the maximum synchronous speed, which can not reach high speed, dc motor (especially brushless motor) can achieve higher speed. The static balance and dynamic balance of high speed motor are high.
