磁力排种元件磁场分析与结构优选

提出了3种带导磁罩的磁力排种元件，并利用磁场有限元分析软件对有、无导磁罩2种磁力排种元件空间磁场特性进行了分析，得出了排种元件磁吸端面以及气隙空间磁感应强度分布规律。分析表明，有导磁罩排种元件漏磁少、磁能利用率高、磁吸端面附近的磁感应强度强，在相同安匝数下其磁吸端面磁感应强度比无导磁罩排种元件高30.41%，说明有导磁罩排种元件的吸种性能优于无导磁罩排种元件。通过对锥形、截锥形和阶梯形3种磁吸端部结构有导磁罩排种元件轴向、横向磁感应强度分析比较，得出有导磁罩锥形结构排种元件为优选结构。通过磁吸端面磁感应强度、最小吸种电流以及排种性能测试，证明了结构优选结果的正确性。

Analysis for Magnetic Field Characteristics of Magnetic Seed-metering Elements and Structure Optimization

Magnetic seed-metering element is the core components of the magnetic precision seeder. In order to improve performance, a new seed-metering element with magnetic shield was put forward. By using FEA software, the magnetic field characteristics were analyzed for two kinds of seed metering elements with and without magnetic shields, respectively. The distribution of magnetic induction intensity was obtained at head face, as well as air-gap space of the two kinds of seed metering elements. The research results showed that the magnetic energy utilization and magnetic induction of the seed-metering element with magnetic shield was higher than the other one which had no magnetic shield, and the intensity of magnetic induction at the end of seed-metering element which had magnetic shield was higher, 30.41% than that non-magnetic shield element on the same number of amperes turns, so it was lustrated that the performance of the element with magnetic shield should be better than non-magnetic shield element. By analyzing and comparing axial and transverse magnetic induction for the three kinds of seed-metering elements with magnetic shields, obtained cone element was the optimal model. The experiments including the intensity of magnetic induction, the lowest electric current and seed-metering performance verified the theoretical analysis and optimized element were correct.