Summary of the main motors used in the industrial field in one article
In the industrial field, small and medium-sized three-phase asynchronous motors are currently the most widely used motor products. Different motors have different application scenarios. With the continuous development of motor manufacturing technology and the deepening of research on motor working principles, many new types of motors have emerged, including rare earth permanent magnet motors, switched reluctance motors, synchronous reluctance motors, etc.

A brief introduction to various types of motors

Small and medium-sized three-phase asynchronous motors are currently the most widely used motor products in industrial applications. Three phase asynchronous motor is a type of AC motor, also known as induction motor. It has a series of advantages such as simple structure, easy manufacturing, durability, convenient maintenance, low cost, and low price. Therefore, it is widely used in industry, agriculture, national defense, aerospace, scientific research, construction, transportation, and people's daily lives. But its power factor is relatively low, which limits its application to some extent.

From the outside of the motor, the fan cover, fan, left and right end caps, nameplate, and junction box can be seen. Open the junction box and you can see the terminal posts and lead wires. Remove the fan cover, fan, and end cap, and pull out the rotor. You can see the internal stator iron core, rotor iron core, shaft, bearings, and other components of the motor. The stator iron core is loaded into the machine base, and the rotor iron core is mounted on the shaft. The stator core has coils (windings), and the rotor core is cast with cage shaped aluminum bars. There are rotor windings in the wound rotor iron core.

Rare earth permanent magnet motor is a new type of permanent magnet motor that emerged in the early 1970s. Rare earth permanent magnet materials have excellent magnetic properties, and after magnetization, they can establish a strong permanent magnetic field without the need for external energy. Rare earth permanent magnet motors made to replace traditional electric excitation fields not only have high efficiency, but also have a simple structure, reliable operation, and can achieve small size and light weight. It can achieve high performance that traditional electric excitation motors cannot match (such as ultra-high efficiency, ultra-high speed, ultra-high response speed), and can also be made into special motors that can meet specific operating requirements.

With the development of permanent magnet synchronous motors, high-efficiency permanent magnet synchronous motors such as high-temperature, high vacuum, electric vehicle use, built-in inverters, low-speed high torque, and self starting have gradually entered some specific application fields. Due to the specific performance requirements of motors under different operating conditions, the overall development direction of permanent magnet motors has gradually shown some specific characteristics.
 
 

High power and ultra-high speed are a development direction for permanent magnet motors

 
To increase the rated power of a motor within a certain volume, it is necessary to significantly increase the motor's speed. Rare earth permanent magnet motors do not require alkali excitation windings and have a relatively simple structure. The magnetic field does not have a heat source and does not require cooling devices. The material has high coercivity and the air gap length can be set to a larger value, making it possible to significantly increase the speed.

High performance rare earth permanent magnet motors are the foundation of many new technologies and high-tech industries. It can be combined with power electronics technology and microelectronics control technology to manufacture various high-performance electromechanical integrated products, such as CNC machine tools, machining centers, flexible production lines, robots, electric vehicles, high-performance household appliances, computers, and so on.