Multi-pole magnetic ring(encoder ring) is widely used in industrial automation, robotic arm, sensor and motor. The accuracy of the magnetic ring directly impacts the output precision of sensor or the encoder.
Therefore, achieving high precision and stability of each magnetic pole is crucial for the manufacturing of multi-pole magnetic ring.
Here are several key factors for enhancing pole accuracy:
1. Optimization of Magnetic Materials for Multi-pole Magnetic Enoder Ring
The magnetic materials used in multi-pole magnetic ring is mainly made of ferrite and rubber.
Ferrite:
Ferrite typically used in these rings includes barium ferrite (BaFe12O19) or strontium ferrite (SrFe12O19). Once magnetized, these materials form stable magnetic fields.
- To increase magnetic field, the sintering process of ferrite can be optimized to enhance material density, tightening the alignment of magnetic domains.
- Increasing the proportion of ferric oxide or adding rare earth elements like cobalt or lanthanum can improve the magnetic saturation strength and hysteresis loop area, leading to stronger magnetization.
Rubber Material:
The rubber used normally is NBR (nitrile butadiene rubber), which provides flexibility for easier processing. When rubber has been bonded with metal ring, it enables multiple installation configurations.
The rubber also provides toughness, allowing the magnetic rings to withstand large temperature variations without cracking.
Optimizing the rubber formulation is key to achieving uniform blending and bonding between rubber and ferrite materials, while also increasing the ferrite content within the rubber.
2. Rubber Compounding Process for Multi-pole Magnetic Ring
Rubber Mixture Process: Ferrite particles naturally have poor adhesion to the rubber matrix, so using appropriate compatibilizers or surface treatments for the ferrite is crucial to improve adhesion and prevent phase separation during processing.
3. Use of High-precision Magnetization Technology
The magnetization process directly determines the arrangement and accuracy of the magnetic poles on the ring. By the multi-pole magnetization devices,we can precisely control the position, strength, and polarity of each pole. The magnetic ring is placed in a magnetization fixture, where powerful current pulses are applied, causing the coils to generate a high-intensity magnetic field. The magnetic material within the ring aligns with this external magnetic field, forming permanent north and south poles around the ring. Since magnetization generates heat, the magnetization equipment must deliver high-energy pulses in a short period to prevent overheating while ensuring magnetic saturation. High-precision magnetization fixtures must be machined to tight tolerances. By selecting high-performance materials, optimizing rubber mixture processe, and using precise magnetization with 100% inspection of pole accuracy, we can control the pole accuracy and stability of multi-pole magnetic ring. Please contact us, OBT Rubber Seal, for better understanding your technical requirement and our proposal.
Magnetic Ring Reference reading:
- How to choose magnetic ring for magnetic encoder?
- How to determine the number of magnetic pole pairs in a multi-pole magnetic encoder ring?
- When to Use Rubber Multi-pole Encoder Rings for Speed detaction
- How to Improve the Accuracy of Multi-pole Magnetic Ring
- Application of Multi-Pole Magnetic Rings in Robot Arms
- 2 Track Nonius Encoder Discs for High-Resolution magnetic encoder Systems
