用于GMA的新型永磁偏置闭合磁路

利用ANSYS有限元软件进行仿真模拟,对超磁致伸缩执行器(GMA,Giant Magnetostrictive Actuator)的磁路结构进行了分析和优化.根据磁致伸缩棒内磁场均匀性好,场外漏磁小的设计目标,利用极性相反的双永磁补偿原理,提出了一种新型的内置式永磁组合偏置结构,使得沿磁致伸缩棒长方向磁场分布均匀的同时,偏置磁场和激励磁场都形成良好的闭合磁路.ANSYS分析结果表明,棒中偏置磁场不均匀度为3.51%,激励磁场不均匀度为8.73%,均满足不均匀度小于10%的设计目标;在执行器指定位置(距离GMA 7 cm)的总漏磁场强度为30.4 A/m,符合实际应用的标准要求(<80 A/m).

Novel closed magnetic circuit with permanent magnet biased for giant magnetostrictive actuator

The magnetic circuit of giant magnetostrictive actuator (GMA) was analysed and optimized with finite element software ANSYS. According to the design goals of high homogeneity of magnetic field and low magnetic flux leakage, a novel magnetic circuit biased by the combination of built-in permanent magnets was proposed in the base of compensation principle of dual-permanent magnets with contrary polarity. Magnetic field along the direction of the length of giant magnetostrictive rod was homogeneous, while well-closed magnetic circuits were informed in both biased magnetic field and driving magnetic field. According to the results from ANSYS analysis, the unevenness of the bias magnetic field and driving magnetic field is 3.51% and 8.73% respectively, which are less than 10%. The total magnetic leakage in the specified location (7 cm from the GMA) is 30.4 A/m , meeting the standard of practical application(<80 A/m).