The formula of speed and frequency of AC motor
Rotational speed / component of n= motor
60= per minute
F= power frequency Hertz
The polar logarithm of the rotating magnetic field of the p= motor.
The frequency of the power supply in China is f=50 weeks / seconds, so the rotational speed of the rotating magnetic field is only related to the logarithm of the magnetic pole. The number of magnetic poles is much, and the rotational speed of the rotating magnetic field is low.
Due to the transfer rate, the motor. The actual speed is slightly lower than the rotational speed of the magnetic field.
With the rapid development of information technology, all kinds of computer peripherals and office automation equipments are highly developed. With the matching of key components, the demand for micro motor is large, and the accuracy and performance requirements are also increasing. The requirements for this kind of micro motor are miniaturization, thinning, high speed, long life, high reliability, low noise and low vibration, and the precision is especially high.
For example, a hard disk drive spindle drive motor is a permanent magnet brushless DC motor, it is nearly 10000rpm high speed driven disk rotation, data read head write function from the disk surface is only 0.1 ~ 0.3 micron for suspension motion on the disc, the high precision to know. Most of the driving motors used in information technology, such as printers, hard disk drives, CD drives, fax machines, photocopiers and so on, are mostly permanent magnet brushless DC motors. Limited by the technical level, this kind of micro motor can not be made in China right now, but some products are assembled at china.