磁悬浮带式输送机新型敛磁式混合磁体设计与试验研究
Design and experimental research on a new type of convergent hybrid magnet for magnetic levitation belt conveyor
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摘要: 针对常规电磁铁——永磁体混合磁体结构易漏磁、能耗大等问题,在E型电磁铁的基础上,提出一种适用于磁悬浮带式输送机支撑系统的新型敛磁式混合磁体。基于磁悬浮带式输送机的运行机理,通过对E型混合磁体漏磁路径的分析,引入新型环形敛磁体对磁路进行改善。以麦克斯韦电磁学基本理论为基础,结合磁路法、积分法和区域划分法,对敛磁式混合磁体的磁通路径进行划分,并建立各处磁通路径的解析式。进一步研究敛磁体结构对磁通的影响,发现随着敛磁体结构变化会产生3种不同的磁通回路,并具体讨论3种磁通下的存在条件和磁路情况,得出通用的电磁力和漏磁系数解析式,进而通过试验验证理论分析的准确性。结合麦克斯韦电磁场有限元软件和Simulink动态系统模型对敛磁式混合磁体的静动态特性进行分析,结果表明敛磁式混合磁体相较于改良前混合磁体在大气隙下降低了约20%的漏磁,提高了约10%的磁通密度,较好地改善了磁路分布,同时敛磁式混合磁体具有更高的悬浮刚度和阻尼,能更快实现稳定悬浮。基于改善磁体效能和减少材料成本的目的,完整分析了敛磁体轴向长度和磁化方向厚度对漏磁系数的影响,发现漏磁系数随磁化方向厚度增加而增大,轴向长度对漏磁系数影响较小,仅在敛磁体对磁通回路进行改变时漏磁系数发生断崖式变化;在Matlab中运用遗传算法对敛磁体结构尺寸进行优化,经过迭代计算后得到最优敛磁体轴向长度和磁化方向厚度均为5 mm。Abstract: Aiming at the problems of magnetic leakage and high energy consumption of conventional electro-magnet-permanent magnet hybrid magnet structure, a new type of convergent hybrid magnet which is suitable for the supporting system of magnetic levitation belt conveyor was proposed on the basis of E-type electromagnet.Based on the operation mechanism of the magnetic suspension belt conveyor, a new type of circular convergent magnet was introduced to improve the magnetic circuit by analyzing the magnetic flux leakage path of the E-type hybrid magnet.On the foundation of Maxwell's electromagnetics theory, combined with magnetic circuit method, integral method and regional division method, the magnetic flux paths of the converged magnet were divided.Also, the analytical expressions of the magnetic flux paths of each part were established.The influence of the structure of the convergent magnet on the magnetic flux was further studied, and three different magnetic flux loops were found with the change of the convergent magnet structure.The existence conditions and magnetic circuit conditions under the three kinds of magnetic flux were discussed in detail, and the general analytical expressions of electromagnetic force and magnetic flux leakage coefficient were obtained.Furthermore, the accuracy of the theoretical analysis was verified by experiment.Combined with Maxwell electromagnetic field finite element software and Simulink dynamic system model, the static and dynamic characteristics of hybrid magnet were analyzed.The results show that compared with hybrid magnet before improvement, the convergent hybrid magnet hybrid magnet reduced the flux leakage by about 20% and increased the flux density by about 10% under large air gap which improve the distribution of magnetic circuit.At the same time, the convergent hybrid magnet had a higher suspension stiffness and damping that could realize stable suspension quicker.On the purpose of improved magnet efficiency and reducing the cost of materials, the influences of the axial length and magnetization thickness of convergent hybrid magnet on the magnetic flux leakage coefficient were analyzed.It was found that the magnetic flux leakage increased with the increase of magnetization thickness, and the axial length had little influence on the magnetic flux leakage, except when the convergent hybrid magnet was used to change the flux loop.Furthermore, the genetic algorithm was used in Matlab to optimize the structure size of the convergent magnet.After iterative calculation, the optimal convergent magnet axial length and magnetization thickness were both 5 mm.