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  •                                                                                  Product Description

                                                                                     NdFeB Halbach magnet is 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.

     

    Halbach Magnets

    Construction

    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. EMT can design, produce and supply Halbach Arrays per customer requirements.

     

    Characteristic

    ● 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.

     

    Application

    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.