“n”型电机最小气隙正态分布计算方法

简述了"n"型防爆电机的最小气隙限值及影响气隙的主要零部件,利用正态分布法计算最小气隙值,并通过实例,比较该方法与一般方法的计算结果,证明用正态分布方法计算更趋符合实际情况。

大功率电动机车用PMSM不对称偏心气隙优化设计

对于大功率电动机车驱动电机,通常减小气隙长度以提高功率密度,但也加剧了电枢反应的影响。结合电动机车单向驱动特性,设计了一种不对称偏心气隙结构。综合考虑车辆舒适性、带载与续航能力,确定了最大最小气隙比为3.2的优化方案。有限元分析表明,与常规结构电机相比,该结构电机可显著抑制负载气隙磁密与反电势畸变,有效提升转矩输出品质与效率。联合仿真进一步验证了该结构电机的有效性和可行性。

输电线路防绕击避雷针的电气设计优化

介绍输电线路防绕击避雷针的电气设计优化部分,对其在针尖戴上绝缘帽和针体串联小气隙能够提高引雷能力进行了原理性分析和理论推导,并进行了电气试验验证。

Rotational Flow in a Narrow Annular Gap Based on Lattice Boltzmann Method

For comprehensive characteristics of flow in a gas bearing,lattice Boltzmann method(LBM)is applied for study of the two-dimensional flow between two eccentric cylinders with the inner one rotating at a high speed.The flow pattern and circumferential pressure distribution are discussed based on critical issues such as eccentricity ranging from 0.2 to 0.9,clearance ratio varying from 0.005 to 0.01 and rotating speed in the range of 3×104—1.8×105 r/min.The analysis and discussion on the circumferential pressure distribution affirmed the quasilinear relation between the extremum pressure and rotating speed.Furthermore,a high eccentricity and small clearance ratio contributes most to the fluctuation of the circumferential pressure distribution.The flow pattern inside the channel exhibits separation vortex under a large eccentricity.The conclusions drawn in this work give rise to prediction of the flow pattern in the gas bearing which is beneficial for evaluating the performance of as well as instructing the design and development.

高效连铸抛物线锥度结晶器的研究与设计

应用凝固理论对高效连铸条件下结晶器内初生坯壳生长规律、铸坯的凝固收缩特性进行了系统研究。利用结晶器锥度设计的最小气隙原则,建立结晶器设计计算模型,开发出高效连铸抛物线锥度结晶器设计系统。该系统可依据工艺条件设计出满足不同钢种和拉速条件的结晶器锥度、内腔曲线方程、上下口以及任意间位置的内腔尺寸,为结晶器的生产提供操作数据和理论依据。最后分别讨论了钢种、结晶器长度、拉坯速度、铸坯断面尺寸与结晶器锥度、凝固收缩系数的关系。