Respective advantages and choose of ferrite multipole ring and ferrite arc magnet

Ferrite multipolar magnetic ring and ferrite arc magnet are two types of magnets commonly used in DC motors. The multipolar magnetic ring is a ring magnet with multiple NS on its surface, while the arc magnet represents one pole. Eight pcs arc magnets are also eight poles. Today, we talk about the advantages and choices of ferrite multipolar magnetic ring and arc magnet.

The multipole magnetic ring and the arc magnet block are assembled into a ring, which can be magnetized externally or internally, and can be used as a rotor or stator. Compared with the structure of the two, the multipole magnetic ring rotor has the advantages of high mechanical accuracy and good concentricity. The multipolar magnetic ring can be easily processed by a coreless grinder, and the outer circle accuracy can be guaranteed to be within 0.05mm, which is crucial to the efficiency and stability of the motor. The arc magnet needs to be processed by a single piece and then assembled by multiple pieces, so the dimensional accuracy is much lower, and the tolerance is often more than doubled.

In addition, the ring core of the multipolar magnetic ring rotor does not need to use magnetic materials, but can use plastic, because a closed magnetic circuit has been formed in the magnetic ring wall. However, the arc magnet combined rotor must be made of silicon steel sheet type magnetic conductive materials, otherwise serious magnetic leakage will occur and the magnetic flux loss will be obvious, leading to the reduction of the magnetic flux density on the rotor surface.

The following figure shows the magnetic pole distribution and surface magnetic flux density of the combined rotor with multipolar magnetic ring and arc magnet

According to the experiments and analysis of some engineers, ferrite multipolar magnetic ring rotor and magnetic tile combined rotor have their own characteristics and corresponding application scope, but there are also areas where the two compete in the cross region. For small rotor magnets, such as those below 40 mm, especially when the number of magnetic poles is large, a reasonable solution is to use multipolar magnetic rings, as is the case at home and abroad. For large power requirements and large rotor size, such as more than 100 mm, it is more reasonable to splice the magnetic pads at present, because the requirements of this large multipolar magnetic ring for equipment are more special, the manufacturing cost increases significantly, and the performance advantage disappears.

In the cross area of the above range, the size of the required rotor magnetic ring is roughly 50~80mm. From the perspective of practical conditions and development prospects, the multipolar magnetic ring has more advantages than the arc magnets. Considering the efficiency, miniaturization, energy saving and cost of the motor, it is more reasonable to use multipolar magnetic ring.

The above is the whole content of this article. If you need to evaluate the price of ferrite multipolar magnetic ring and ferrite bending segmented magnet, please consult the courage magnet manufacturer.

These magnets are also commonly used in motors;

Bonded Neodymium Magnets

Injection Molded Ferrite Magnets

Neodymium Arc Segment Magnets

Radially Magnetized Ring Magnets