Papers by Keyword: Permanent-Magnetic Materials

Abstract: In this paper, the green body was prepared by pre-roasted material of strontium ferrite, adding 0.2 to 9% the rare earth additive, by wet milling and forming into pellets Φ30×10 mm under magnetic field. Then, the green body was sintered separately by microwave sintering (MS) method and conventional sintering (CS) technique. The results showed that: the strontium ferrite samples with the same magnetic properties Br and (BH) max were 420 ± 10mT and 33.0 ± 2 kJ/m 3) were synthesized by microwave sintering (MS) method against conventional sintering method, the sintering temperature and time were reduced 150~300°C and 5~6h. Therefore, microwave sintering method will significantly decrease energy consumption. Further analysis revealed that the major improvements in microwave sintering were the material microstructure, the grain size was significantly reduced, the magnetic domain short-range order was increased so that the degree of orientation was increased, and although the fusion was existed between grains, the grain boundaries did not disappear.

Abstract: A new-type of solid rotor asynchronous magnetic coupling which works on the principle of electromagnetic induction is researched by ourselves. This kind of asynchronous magnetic coupling can solve the problem effectively that the permanent magnets on its inner rotor is demagnetized if its temperature is too high, because its inner rotor need not the permanent magnets. in order to study the transmission capability of the new-type magnetic coupling, its magnetic field should be analyzed. Because of its magnetic field variety, it is extremely complicated and a precision result is difficult to be got by the analytic method of the magnetic field calculation. Here the software ANSYS FEM is used to analyze its magnetic field. And some formulas were deduced and used to calculate its torque. The experimental and calculational results indicate that this design is practicable.

Abstract: The magnetic coupling can availably solve the leakiness problems of machine equips. But there is a problem currently in the common synchronous magnetic coupling that the inner rotor magnet steel is demagnetized under high temperature. According to reverse design method, a kind of novel permanent induction magnetic coupling is researched. Its inner rotor is similar to that of asynchronous motor, and it does not need permanent magnet material. So it can be used in both normal and high temperature and is free from transporting medium temperature. Because of the variety of magnetic field, it is extremely complicated. Here the software ANSYS FEM is used to analyze it. Its main process can be divided into three steps: solution preprocess, solution process and solution postprocessing, thus the magnetic field strength value of every point of the coupling can be gotten, and it can be shown conspicuously with the sketches or charts. Then the power and torque also can be solved accordingly.