Radially Oriented Ring Magnets

Sintered Neodymium Radially Oriented Ring Magnets (also known as Multi Poles Magnetic Ring, Radial Multipole Magnet Ring, Skewed Pole Pattern Radial Ring Magnet, Neodymium Anisotropic Sintered Ring Magnet, Multipolar sintered neodymium ring magnet) is a special kind of Neodymium magnets. The direction of magnetic field is along the radial vector of the ring and it can be magnetized single-pole, multi-poles (In theory, any number of poles can be magnetized), and skewed pattern. Using proprietary technologies, a multipole ring can be sintered into a truly radial geometry to replace the commonly used arc/segment magnets.

It has the following advantages:

The cylindrical shape enables higher precision in external dimensions.
As a rotor, can achieve uniform magnetic density flux distribution. Increased motor efficiency and torque.
Fastening the magnet is simple, enabling assembly-related cost reductions.
Highly reliability due to enabling rotor construction from a single magnet.
Optional magnetization, including free multiple magnetization, skew-type magnetization possible.
Can obtain sine surface inductive flux distribution.
Improved cogging and higher efficiency.
Improved the utilization rate of raw material.
Better corrosion resistance due to the absence of internal porosity.

These multi-pole neodymium rings are being widely used in:

Magnetic Drive
Servomotor
Actuators
Magnetic Bearings
Magnetic Clutch
Peripheral Motors
Spindle Motors
Steering Control Motors
Stepper Motors
Synchronous Motor
Hall Sensor
Other new products

Because the direction of the magnetic field during radial orientation molding is perpendicular to the pressing direction, the production method of this kind product is much more complicated than that of ordinary products. Since most of these products are barrel-shaped, with thin walls and large axial dimensions, it is difficult to form. During the sintering process, due to the differences in shrinkage and thermal expansion coefficients in all directions, to avoid product cracking, a lot of improvements in materials and processes are required to ensure good product performance and pass rate. Multi-pole magnetization generally adopts the pulse current of capacitor discharge. For different sizes products, orientation coil and magnetization fixture are very specific, they are not universal.

Grade Available :
N35-N50, N35M-N50M, N35H-N48H, N35SH-N45SH, N35UH-N40UH, N28EH-N33EH.

Surface treatment:
These magnets can be covered by any available coatings, like NiCuNi, Ni, Zn, epoxy etc.

Customized Dimension Range:
Maximum outside diameter is 60 mm
Minimum inside diameter is 10 mm
Maximum thickness between outer and inner is 8 mm
Minimum thickness between outer and inner is 2 mm
Maximum height is 40mm
Tolerances: +/- 0.05 mm

For this kind product, the customers should bear the cost of orientation coil and magnetization fixture, and therefore the development cost of this kind of magnet is very expensive. However, because we have many years of production experience, we have ready-made orientation coils for most used specifications, and customers do not need to pay additional fees.

Available Dimension with Free Cost of Ready-Made Orientation Coils:

Outer Diameter
(mm)

Inner Diameter
(mm)

Height
(mm)

Thickness Between Outer and Inner (mm)

16.2	10.8	20	2.7
17.8	10.8	20	3.5
20.3	10.8	20	4.75
20.3	14	20	3.15
21	13.5	16	3.75
22	14	20	4
23	17.5	20	2.75
24.5	14	22	5.25
24.5	17.5	20	3.5
25.6	17.5	18	4.05
26	17.5	20	4.25
25.6	18	18	3.8
29	19.5	20	4.75
30	18	18	6
30.5	20.5	24	5
30.5	22	21	4.25
31	17.5	20	6.75
31	22	21	4.5
31	22	47	4.5
32.5	23.5	21.6	4.5
32.5	24	21.5	4.25
32.8	23	22	4.9
35.5	23	22	6.25
35.5	27	25	4.25
36	25	23.5	5.5
36	26	25	5
39.5	26	24	6.75
40.5	22	47	9.25
40.5	27.5	54	6.5
40.5	30	45.5	5.25
40.5	30	54	5.25
41	21	39	10
41	32	29	4.5
41.8	32	29	4.9
43	16	24	13.5
43	30	28	6.5
43	32	28	5.5
44.8	30	54	7.4
45.8	34.8	29	5.5
46	22	38	12
46	28.5	24	8.75
46	30	28	8
46	33.5	24	6.25
46	35	29	5.5
47	36.5	26	5.25
53.5	30	45.5	11.75