Are injection moulded magnetic rings suitable for use in air conditioning systems?

The motors inside air conditioners are required to operate continuously, which places certain demands on the stability, durability and cost of the magnets. As a commonly used magnetic component in motors, injection-moulded magnetic rings are increasingly being utilised in the air conditioning industry. Put simply, injection-moulded magnetic rings are well-suited for use in air conditioners, particularly in fan motors, where they meet the requirements for stable operation, low noise levels and mass production.

The most notable feature of injection-moulded magnetic rings is their ease of manufacture. They are produced by mixing magnetic powder with plastic material and moulding the mixture via injection moulding, allowing them to be directly manufactured in various sizes and with different numbers of magnetic poles. Compared to traditional magnetic tile structures, injection-moulded magnetic rings offer better dimensional consistency and are easier to install; they also exhibit superior stability during high-speed motor rotation, effectively reducing vibration and noise during motor operation.

In air-conditioning products, injection-moulded magnetic rings are primarily used in components such as indoor unit fan motors and outdoor unit fan motors. Whilst these motors do not require particularly extreme magnetic performance, they must operate reliably over long periods whilst keeping costs under control. Injection-moulded magnetic rings are lightweight and offer high production efficiency, making them highly suitable for the mass production of air-conditioning motors. Furthermore, their multi-pole magnetisation characteristic meets the magnetic field distribution requirements of brushless motors.

The accompanying image shows an injection-moulded ferrite magnetic ring

Of course, injection-moulded magnetic rings are not the optimal choice for all air-conditioning motors. For high-performance inverter compressor motors, which demand higher efficiency and output power and require a stronger magnetic field, sintered neodymium-iron-boron or bonded neodymium-iron-boron is generally selected. By comparison, standard injection-moulded magnetic rings offer slightly lower magnetic performance and are better suited to motor applications requiring medium to low power output and high reliability.

Overall, injection-moulded magnetic rings for air conditioning applications represent a cost-effective solution. For applications such as air conditioning fans and small brushless motors, injection-moulded magnetic rings offer clear advantages in terms of cost, manufacturability and stability. The choice of magnet type ultimately depends on the motor’s power rating, rotational speed, operating environment and the customer’s performance requirements.

Collection of articles on injection-moulded magnetic rings;

Injection Molded Ferrite Magnet Surface Gauss Strength

How is the injection molded magnet made? Production process diagram