Halbach Array Magnets
Halbach Array Magnets, NdFeB Halbach Magnets, Halbach magnetic ring, Magnetic-Bearings & Halbach Arrays, Halbach Array Cylinder Neodymium Segment Magnets China Supplier
NdFeB Halbach Array Magnets are a special magnetic component consisting of NdFeB permanent magnets that can provide controlled high magnetic field strength without the use of magnetically permeable materials. Halbach magnets, with the smallest magnet through a certain direction of magnetization to produce the strongest magnetic field to reduce the cost of materials.
The most obvious benefit of a Halbach Array is that the field produced is very strong when compared to other arrays having the same amount of the magnet alloy. The arrangement essentially increases the efficiency of the magnetic circuit. A Halbach array is an arrangement of permanent magnets that causes an one-sided flux, i.e. the magnetic field is maximized on one side, while minimized on the other.
● Power density is big
Compared with the traditional permanent magnet motor structure, Halbach magnets design motor can effectively reduce the size of the motor to and enhance the motor power density. This is because the Halbach magnetic ring after disassemblied the parallel magnetic field and the radial magnetic field overlap with each other so that the other side of the magnetic field strength greatly improved.
● The rotor does not need a chute
In the traditional permanent magnet motor, due to the inevitable existence of air gap magnetic field harmonics,generally in the fixed rotor structure to take the chute to weaken its impact. In the Halbach motor, because the air gap magnetic field sine distribution is high, harmonic content is small, so the stator without chute.
● The rotor can be made of non-core material
Since the unilateral magnetic field distribution produced by the self-shielding effect of the Halbach magnet eliminates the need for the rotor to provide a path for the magnetic material, which not only provides a larger choice for the rotor material, but also allows the system to have a lower moment of inertia and good attached performance.
● Permanent magnet utilization is high
As the Halbach magnet is divided into magnetized results, resulting in its permanent magnet operating is higher that generally more than 0.9,it enhances the utilization of permanent magnets.
Halbach Magnet’s main function is holding, fixturing, linear coupling application, so it is mainly used for motor, generator, magnetic resonance, magnetic levitation high-speed rail,pre-polarization, chemical single crystal growth. For example, the traditional permanent magnet motor often use distributed winding to weaken the influence of harmonic magneto motive force. In the Halbach motor because of its high magnetic field sine distribution, harmonic magnetic field less affected, it can be used centralized winding. With Halbach motor magnet arrangement, can reduce the torque ripple of the motor, so the bearing requirements for the motor greatly reduced.
In addition, the magnetic levitation super high-speed rail is the principle of passive rejection, its periphery is surrounded by a series of magnets. These magnets are arranged in the Halbach array so that the train has an outward magnetic force, not to the passenger’s end. Each cabin is suspended in the air, not contact with the ground, that makes running up without friction. It is because there is no friction and close to the vacuum, it makes the train can achieve very fast speed.
The common arrangement of Halbatch array for block magnets:
The common arrangement of Halbatch array for circular magnets:
From these above diagrams ,the Halbach component is made of a variety of shapes version, with ring array and linear array and customized design dimensions. You can see from the design of the designed each arc has a direction of magnetization, making the magnetic field through the central air gap, and then be guided through the magnet material itself around. The ring array / linear array can be made from more arcs (the greater the number of segments, the better of the field uniformity in the center air gap).
Magnetic filed viewed through magnetic viewer: