The number of pole of the motor

In the world of motors, 'series' is a crucial concept. It not only affects the performance of the motor, but also determines its applicability in different application scenarios.

1、 What are the stages of a motor?

The number of stages of a motor refers to the number of magnetic poles in the stator winding of the motor. Simply put, it is the number of poles in the magnetic field of a motor. For example, a 2 pole motor has one pair of magnetic poles, and a 4 pole motor has two pairs of magnetic poles.

2、 Method for representing the number of motor stages

The number of stages of a motor is usually represented by numbers, such as 2 pole motor  (3000rpm),4 pole motor (1500rpm), 6 pole motor (1000rpm), 8 pole motor (750rpm), etc. The higher the number of pole, the more magnetic pole pairs there are.

3、 The influence of motor stages on motor performance

Rotational speed :

The speed of the motor is closely related to the frequency and stage of the power supply. At a constant power frequency, the speed of the motor is inversely proportional to the number of stages. The more stages there are, the lower the rotational speed. For example, the synchronous speed of a 2 pole motor is usually 3000 revolutions per minute, the synchronous speed of a 4 pole motor is 1500 revolutions per minute, the synchronous speed of a 6 pole motor is 1000 revolutions per minute, and the synchronous speed of an 8 pole motor is 750 revolutions per minute.

Torque :

Generally speaking, the higher the number of motor stages, the greater the torque. This is because an increase in the number of stages means an increase in the number of magnetic poles, an increase in magnetic field strength, and thus the ability to generate greater torque. However, the magnitude of torque is also influenced by factors such as the power and current of the motor.

Efficiency:

 Motors of different levels also have differences in efficiency. Normally, motors with lower stages have higher efficiency during high-speed operation, while motors with higher stages have relatively higher efficiency during low-speed operation. When choosing a motor, it is necessary to comprehensively consider efficiency factors based on specific application scenarios and work requirements.

4、 Application scenarios of motor series

2 pole motor:

The 2-level motor has a high speed and is suitable for equipment that requires high-speed operation, such as fans, pumps, etc. Due to its high speed, the second stage motor has a relatively small volume, light weight, and easy installation. In some specific mechanical equipment, 2-pole motors also play an important role. For example, in some high-speed mixing equipment, a 2-pole motor can provide sufficient speed to make the mixing more uniform and fast. In some mechanical systems that require fast transmission, 2-pole motors can also serve as power sources to achieve efficient transmission2. 

4 pole motor:

The 4 pole motor has moderate speed and high torque, and is widely used in various industrial equipment such as machine tools, compressors, etc. In some situations where there is a balance between speed and torque requirements, a 4 pole motor is a good choice. In the field of construction, some small cranes and lifting equipment may use 4-pole motors. It’s torque can meet the lifting and hoisting requirements of a certain weight, and the moderate speed is also easy to operate and control, ensuring the safety and efficiency of the construction process.

6 pole motor:

The 6 pole motor has a low speed and high torque, making it suitable for equipment that requires high torque and low speed, such as cranes, mixers, etc. In the industrial field, some heavy equipment that requires high torque and low-speed operation often uses 6-pole motors. For example, in mining crushers, 6-pole motors can provide continuous and stable high torque to crush hard ores into suitable sizes. Large ball mills in cement production also use 6-pole motors, which can drive heavy grinding balls to rotate and fully grind cement raw materials. In the steel rolling equipment of the metallurgical industry, the high torque characteristics of 6-pole motors help to push heavy steel for rolling processing.In the field of construction, large cranes are usually equipped with 6-pole motors. This type of motor can provide strong pulling force during the slow lifting of heavy objects, ensuring the safe and reliable lifting operation of the crane. The concrete mixer also uses a 6-pole motor, whose high torque can fully mix the concrete in the mixing tank, ensuring the quality of the construction project.In some special mechanical equipment, such as large printing machines, paper machines, etc., 6-pole motors also play an important role. It can provide stable power output at lower speeds, meeting the precise control and high torque requirements of these devices. These motors are usually large in size, heavy in weight, and relatively complex to install and maintain.

8 pole motor:

The 8 pole motor has important applications in specific fields due to its unique performance characteristics.In some large industrial pumps, an 8-pole motor can play an important role. For example, in the petrochemical industry, large oil pumps require stable high torque and low speed to ensure smooth transportation of crude oil and other media, and an 8 pole motor perfectly meets these requirements. In the drainage pumps of mines, 8 pole motors can reliably handle the task of discharging large amounts of accumulated water. Their low speed and high torque help overcome pipeline resistance and improve height.In large ventilation systems, an 8 pole motor can drive large fans. For some situations that do not require particularly high air volume, but require stable, continuous air supply and relatively low noise, the low-speed operation characteristics of an 8 pole motor can reduce fan vibration and noise, while providing sufficient torque to drive air flow.In some special processing equipment, such as large spinning machines, 8-pole motors can provide uniform and high torque power output, ensuring the accuracy and stability of metal sheets during the processing.

5、How to choose the number of motor stages?

When selecting the number of motor stages, the following factors need to be considered:

  • Job requirements: Determine the required speed and torque range based on the working requirements of the equipment. If high-speed operation is required, motors with lower levels can be selected; If a high torque is required, a motor with a higher number of stages can be chosen.

  • Power supply conditions: Consider the frequency and voltage stability of the power supply. Different levels of motors may have different requirements for power supply.

  • Installation space and cost: Motors with higher levels usually have larger volumes and require more installation space. Meanwhile, the price of the motor will also increase with the number of stages.

  • Reliability and maintenance: Some motors with higher levels may require more complex maintenance and upkeep, so reliability and maintenance costs need to be considered when selecting.In short, the number of stages of a motor is an important indicator of its performance. 


Understanding the concept and characteristics of motor stages can help us make more informed decisions when choosing motors to meet the needs of different application scenarios.

Shandong Fuxing Motor is a professional induction motor manufacturer and supplier in China, and one of the most cost-effective manufacturers in China. We are located in Shandong Province, China. After years of development, we have become a professional manufacturer and supplier of three-phase asynchronous motors that integrates research and development, production, sales, and after-sales service. Fuxing has rich OEM and ODM experience and strong R&D capabilities. We have modern production and processing equipment, complete assembly lines, sophisticated testing equipment, scientific production process layout, strict on-site management, and quality inspection system. The company's main products include IE2 (YE2 YBX3) series three-phase asynchronous motors, IE3 (YE3) series three-phase asynchronous motors, IE4 (YE4) series three-phase asynchronous motors, IE5 (YE5) series ultra high efficiency three-phase asynchronous motors, YBX3 (YBX4) series explosion-proof three-phase asynchronous motors, MS (YS) series aluminum alloy shell three-phase asynchronous motors, VF2 (YVP) series variable frequency speed control motors, YEJ series brake motors, YBBP series explosion-proof variable frequency three-phase asynchronous motors, TYC series permanent magnet synchronous motors, etc. It has obtained ISO9001-2008 quality certification, CE certification, CCC certification, and its products are widely used in machine tools, fans, water pumps, compressors, packaging machinery, mining machinery, construction machinery, etc. Mechanical transmission devices such as food machinery. Our basic requirements are ultra-high cost-effectiveness, exquisite craftsmanship, strong power, and complete certification. We have exported to more than 20 countries and regions and achieved good performance and reputation. Fuxing Electric is willing to develop and progress together with customers and friends from all over the world, and make every effort to provide the best products and higher quality services for friends from all over the world. If you also need to purchase three-phase asynchronous motors from China, choosing us is your best choice. If you are interested in our products or have any questions, please feel free to contact us and we will reply to you as soon as possible.


Quickly Inquiry