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sales@tujinmagnet.com
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+86-18858010843
Conclusion: Neodymium ring magnets in electric motors create a seamless, alternating magnetic field via multi-pole magnetization, enabling smooth torque production, reduced cogging, and higher efficiency compared to segmented arc magnets. A ndfeb ring magnet for motor is a single-piece cylindrical magnet with alternating north and south poles on its inner or outer diameter. When mounted on the rotor, it interacts with stator windings to generate rotational motion. The continuous magnetic circuit of a multi pole ring magnet neodymium eliminates gaps between individual segments, resulting in lower torque ripple (typically 3-5% vs. 8-12% for arcs) and quieter operation. As a custom neodymium ring magnet manufacturer, Ningbo Tujin produces radially oriented rings with precise pole counts (4 to 32 poles) for BLDC motors, servo motors, and EV traction applications.
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A neodymium ring magnet is magnetized using a specialized fixture that creates alternating north and south poles around the circumference — a process called multi-pole radial magnetization. When the ring is attached to the rotor (surface-mounted or embedded), the alternating magnetic field interacts with the stator's electromagnetic coils. By sequentially energizing the stator phases, the rotor experiences continuous magnetic attraction and repulsion, producing smooth rotational torque.
Torque Ripple Comparison: Ring Magnet vs. Segmented Arc Magnets
Seamless ring design reduces torque ripple by 40-60%, enabling smoother low-speed operation
The seamless construction of a multi pole ring magnet neodymium ensures a perfectly uniform air gap, minimizing cogging torque and vibration. This is especially beneficial for precision applications such as robotics, medical devices, and electric power steering systems.
Depending on the motor topology and mounting method, different ring magnet configurations are used. The table below summarizes common types found in BLDC, PMSM, and stepper motors.
| Ring Magnet Type | Magnetization Direction | Typical Pole Count | Common Motor Applications |
|---|---|---|---|
| Outer-diameter multi-pole | Radial (poles on OD) | 4-24 | Inrunner BLDC motors, spindle motors, power tools |
| Inner-diameter multi-pole | Radial (poles on ID) | 6-32 | Outrunner hub motors, e-scooters, drone motors |
| Axial multi-pole ring | Axial (through thickness) | 4-16 | Axial flux motors, pancake motors, compact drives |
| Diametral ring magnet | Diametral (2 poles) | 2 | Small DC motors, circulation pumps, sensors |
A ndfeb ring magnet for motor can be manufactured as a sintered ring (higher energy product, up to 52 MGOe) or as a bonded ring (injection-molded NdFeB with polymer binder) for complex multi-pole patterns at lower cost. Sintered rings are preferred for high-performance motors due to their superior magnetic flux density.
Higher pole counts increase torque density but require more precise magnetization fixtures. A 24-pole ring magnet produces a shorter magnetic path, reducing iron losses at low speeds. For high-speed motors (20,000+ RPM), lower pole counts (4-8 poles) are generally preferred to minimize switching frequency and eddy current losses. Most industrial servo motors use 8-12 pole ring magnets.
Traditional permanent magnet motors often use individual arc magnets glued to the rotor surface. A seamless ring magnet offers several distinct engineering benefits:
Motor Efficiency Comparison at 10,000 RPM
Ring magnets improve motor efficiency by reducing flux leakage and eddy current losses
For high-speed applications such as drone motors, turbo blowers, or electric vehicle traction drives, a multi pole ring magnet neodymium provides reliable performance without the risk of segment detachment. As a custom neodymium ring magnet manufacturer, Ningbo Tujin offers high-temperature grades (SH/UH/EH) to withstand thermal stress in demanding environments.
Producing a high-quality ndfeb ring magnet for motor requires precision sintering, grinding, and specialized multi-pole magnetization. The typical manufacturing workflow:
The magnetization fixture for a multi pole ring magnet neodymium is critical to motor performance. Each pole must have consistent magnetic flux density to ensure smooth torque output. Advanced fixtures use computer-controlled pulse currents to achieve precise pole transitions.
| Parameter | Value | Unit |
|---|---|---|
| Remanence (Br) | 1.32 - 1.38 | Tesla |
| Coercivity (Hcj) | ≥1,594 | kA/m |
| Max Energy Product (BHmax) | 318 - 342 | kJ/m³ (40-42 MGOe) |
| Max Operating Temperature | 150 | °C |
| Available Pole Counts | 4, 6, 8, 12, 16, 24, 32 | poles |
Ningbo Tujin Magnetic Industry Co., Ltd specializes in the manufacturing and sales of high-performance NdFeB magnets. With years of expertise in magnetic materials, we excel in providing high-temperature-resistant motor magnets and customized magnetic solutions with superior precision and stability. Renowned for our exceptional product quality, fast lead times, and high flexibility, we have become a trusted long-term partner for leading companies across multiple industries.
Core Product Advantages:
Industry-Wide Solutions: Beyond motors, our magnets are widely used in speakers (audio magnets), sensors, wind power, etc. At Tujin Magnetic Industry, we are more than a manufacturer & supplier — we are your innovation partner. Whether for standard or custom solutions, we deliver professionalism, efficiency, and reliability to empower your products with superior magnetic performance!
As a dedicated custom neodymium ring magnet manufacturer, Tujin provides full engineering support from design to production. Our ndfeb ring magnet for motor solutions are used in EV traction motors, industrial servos, home appliance motors, and e-mobility drives. Whether you need a multi pole ring magnet neodymium with 8, 12, or 24 poles, we deliver precision-magnetized rings with consistent flux distribution and high thermal stability.
No.107 Yunshan Industry Park, Sanqishi Town, Yuyao, Ningbo, Zhejiang 315412, China
+86-18858010843
sales@tujinmagnet.com
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