基于磁热耦合仿真的筒式永磁调速器散热研究

针对筒式永磁调速器长时间运转发热严重的问题,利用磁热耦合分析方法,建立磁场、温度场分析的数学模型和有限元模型,通过Maxwell 3D和Steady-State Thermal模块联合仿真,得到铜环、永磁体温度场分布情况。通过对散热片进行优化仿真,显著降低了铜环和永磁体的最高温度。     

Development and Analysis of the Magnetic Circuit on Double-Radial Permanent Magnet and Salient-Pole Electromagnetic Hybrid Excitation Generator for Vehicles

With the improvement of vehicles electrical equipment, the existing silicon rectification generator and permanent magnet generator cannot meet the requirement of the electric power consumption of the modern vehicles electrical equipment. It is di cult to adjust the air gap magnetic field of the permanent magnet generator. Consequently, the output voltage is not stable. The silicon rectifying generator has the problems of low e ciency and high failure rate.In order to solve these problems, a new type of hybrid excitation generator is developed in this paper. The developed hybrid excitation generator has a double-radial permanent magnet, a salient-pole electromagnetic combined rotor,and a fractional slot winding stator, where each rotor pole corresponds to 4.5 stator teeth. The equivalent magnetic circuit diagram of permanent magnet rotor and magnetic rotor is established. Magnetic field finite element analysis(FEA) software is used to conduct the modeling and simulation analysis on double-radial permanent magnet magnetic field, salient-pole electro-magnetic magnetic field and hybrid magnetic field. The magnetic flux density mold value diagram and vector diagram are obtained. The diagrams are used to verify the feasibility of this design. The designed electromagnetic coupling regulator controller can ensure the stable voltage export by changing the magnitude and direction of the excitation current to adjust the size of the air gap magnetic field. Therefore, the problem of output voltage instability in the wide speed range and wide load range of the hybrid excitation generator is solved.     

基于磁隙式吸附机构的槽车清洗机器人

给出了一种基于磁隙式吸附机构的槽车清洗机器人机构设计方案,采用磁隙式吸附装置平衡清洗作业过程中高压水枪反向冲击力产生的倾覆扭矩,提高系统稳定性裕度。建立数学模型描述清洗作业力学行为,利用有限元仿真优化磁吸附模块设计参数,计算不同气隙高度下单个磁吸附装置产生的吸附力。根据仿真结果,当采用2块40 mm×40 mm×15 mm与2块80 mm×40 mm×15 mm的永磁铁,磁铁间隙为10 mm,轭铁厚度为9 mm,气隙高度为10 mm时,单个磁吸附装置能够产生693 N的吸附力,槽车清洗机器人能够在20 MPa的清洗水压下稳定地工作。     

Structure optimization for magnetic equipment of permanent magnet retarder

The main purpose of this research is to perform a magnetic analysis on the magnetic equipment of permanent magnet retarder (PMR) and optimize the structure of magnetic equipment with the commercial FEM software ANSYS and its design optimization module. The FEM model is built as an axisymmetric model according to the characteristics of the structure of magnetic equipment. Using this model, the magnetic field distribution and magnetic force are calculated by ANSYS. The mathematical model of structure optimization is also built. The design variables are structural parameters including the dimensions of permanent magnets and magnetic yoke, and the objective function is the magnetic force. The unconstrained optimization model takes the maximum value of magnetic force as the objective. A first-order optimization method is used to determine the optimum design of this problem. The optimization process works entirely with the ANSYS parametric design language (APDL). The design tools are used to understand design space and the behavior of the dependent variables. It is shown that designing a structure with the ANSYS optimization module and its design tools is an effective means to improve the structure.     

整体双层盘式永磁涡流联轴器及其转矩特性分析

基于对传统单层盘式永磁体涡流联轴器的磁路分析,设计了一种整体双层盘式永磁体涡流联轴器。该联轴器将两个单层盘式永磁涡流联轴器的永磁体以N-S对应的方式安装到一块背铁的正反面上,减小了背铁磁阻在磁路中带来的损耗,提高了永磁体的磁能利用率,增大了转矩。通过等效磁路法建立该结构的数学模型,并与有限元法仿真模型相结合,综合分析了其转矩特性。搭建了该永磁涡流联轴器的样机,通过实验验证了上述分析的可靠性。结果表明：所建数学模型准确,并且该联轴器的转矩相对于传统永磁涡流联轴器转矩有较大提高。     

Three-dimensional electromagnetic analysis and design of permanent magnet retarder

An eddy current retarder for vehicles generates much heat when it works continuously, which leads to serious decline in braking torque. This paper proposes a novel permanent magnet retarder (PMR) for vehicles, whose cooling system connects with engine cooling-water. A three-dimensional finite element model is developed to model the electromagnetic behavior of a permanent magnet retarder under a constant speed. The magnetic field and eddy current field in PMR are numerically solved by a finite element method. By accounting for the nonlinear permeability of the rotor and the weakened effect in the magnetic field that is generated by the eddy current magnetic field, the calculation accuracy of air-gap magnetic field is enhanced. Experiment shows that the temperature of the retarder is less than 150°C, and the braking torque keeps the hard characteristics curve. The calculated air-gap magnetic flux density is fairly good agreement with the measured one.     

Magnetic torque maximization in a camera shutter module by the topology optimization

In recent years, there has been a stronger demand for the weight reduction of components of various portable electronic devices. This work is motivated by the need to reduce the weight of a camera shutter module without much decreasing the torque generated by its magnetic circuit. Because the camera shutter speed is most significantly affected by the torque, the magnitude of the generated torque should also be considered in the design for the weight reduction. Thus, we formulate the design problem as a torque maximization problem under various mass constraints. Specifically, we propose to formulate it as a topology optimization problem of magnetic circuits and find optimal shapes of yokes (and magnets) in the circuits. For the maximization formulation, the objective function is chosen as the average of clockwise and counterclockwise torques over a whole range of rotation angles of a magnet corresponding to the shutter opening angle. Limits on the mass of the yoke and magnet in a magnetic circuit are imposed as constraints. The torque generated by a magnetic circuit is calculated by the modified Maxwell stress tensor method. A series of mass constraint ratios is considered to investigate the effects of the mass usage on the magnitude of torque generated by optimized circuits. The region occupied by the yoke (and the magnet) is designated as a design domain, while coils are assumed to belong to a non-design domain. By demonstrating that the optimized magnetic circuits outperform a nominal circuit, the use of the average torque as an objective function including a corresponding treatment of a rotating magnet proposed in this work is shown to be effective for the topology optimization of magnetic circuits in a camera shutter module.     

高精度DY稳恒磁场测试仪的研制及应用

本文首次将霍尔效应与锁相技术结合起来，制成高精度稳恒磁场测试仪，并采用回归分析法，成功地用于监视器偏转线圈，特别是各种永磁校正元件的磁场分布的测量及分析，能对优化偏转线圈的结构，永磁校正元件的设计工作提供实际的指导。     

大间隙磁力传动系统驱动规律的仿真研究

针对已提出的大间隙行波磁场驱动的磁力传动系统,采用现代计算技术和数值计算中的有限元理论,运用ANSYS软件的磁场分析功能,建立了磁力传动系统的实体模型和有限元模型,通过模拟永磁体的角位移和电磁体线圈的通电状态,对系统工作过程进行了仿真;研究了系统永磁体在转动过程中的受力情况和各参数对系统驱动能力的影响规律,并进行了实验验证。研究结果表明:通过增加线圈匝数、线圈通电电流、永磁体外径和永磁体磁化强度,减小电磁体和永磁体间耦合距离,将电磁体和永磁体的相对位置沿x方向两侧(左侧或右侧)置于5 mm～10 mm范围内等方法,可提高系统的驱动力矩。     

一种径向永磁轴承设计与研究

建立一种径向永磁轴承系统,永磁轴承的设计便被简化为单端径向永磁轴承设计与分析。采用ANSYS磁场求解方法,建立单端径向永磁轴承3D有限元模型,分别得出动静磁环轴向宽度、径向宽度、截面面积和间隙对其径向承载刚度的影响,这为此类径向永磁轴承的设计提供了优化依据。     

[车辆工程与测控]基于增强磁场涡流的高速轨道缺陷检测方法

在高速轨道运输领域中,电涡流检测以其非接触、易实现自动化等特点,被广泛应用于钢轨表面缺陷的检测,然而,由于趋肤效应的存在,涡流检测很难探测出内部伤损。提出了一种增强磁场涡流以抑制趋肤效应的方法：在涡流检测线圈之上增加一个通入直流电流的U形电磁铁,用磁轭导磁到钢轨以增强磁轭下的磁场。通过ANSYS软件进行有限元仿真,分析了增强磁场后涡流渗透深度的改变,同时仿真研究了磁轭的提离和间距对检测效果的影响。搭建了高速轨道检测的实验平台,进行了增强磁场涡流实验,结果表明,适当地增大背景磁场能够使涡流检测到深层次的缺陷并可以提高检测信号的信噪比。     

基于Comsol的矩形磁控溅射靶磁场模拟与分析

磁控溅射靶表面磁场分布与靶材刻蚀特性、薄膜沉积均匀性密切相关.为确定合适的磁控靶结构参数以改善靶材表面水平磁场分布均匀性,采用Comsol软件建立矩形平面磁控溅射靶三维模型,对靶材表面磁场分布进行模拟与分析,研究永磁体结构尺寸和磁轭尺寸对磁场分布的作用规律,得到靶材表面水平磁场分布均匀、水平磁感应强度范围合理的溅射靶结...     

嵌入式智能球铰链设计及研制

精密球铰链在并联机构中应用广泛,但其在被动运动中,其回转方位及回转角无法自知。基于磁效应,提出一种霍尔传感器与永磁体组合的回转方位辨识及角度测量新方法。在球头上嵌入永磁体,在球窝上植入霍尔传感器阵列,当球头回转时,霍尔传感器阵列测量磁感应强度的变化,反解出角度信息。在完成理论建模、仿真计算和可行性试验的基础上,完成了嵌入式样机的研制。在实现信号冗余计算的基础上,优化了反解算法,基本实现了球铰链多维回转角度的实时测量。球铰链也从单纯的精密传动部件转变为集传动和感测为一体的综合智能部件。随研究的继续,其精度将有大幅提高,有望应用到精密工程中。     

基于电磁力控制的非接触式二维力触觉再现系统

力触觉再现提供了操作者与虚拟物体间的双向信息和能量交互,有效提高了虚拟现实等应用系统的真实感、沉浸感和 操作效率,成为人机交互的新兴技术和研究热点。 本文实现了一种新型的基于电磁力控制的二维力触觉再现系统,该系统由二 维背景电磁场产生和控制模块、指尖穿戴式永磁铁、人手位置检测模块和中央控制模块组成。 基于 ANSYS 有限元分析,确定了 系统中背景电磁铁线圈和指尖永磁铁的最优参数,获得指尖永磁铁所受电磁力与二维可控背景电磁铁驱动电流、指尖电磁铁位 置的映射关系,形成离线仿真数据。 提出了基于离线仿真数据实时插值的二维力触觉再现中电磁力控制方法。 在实现系统原 型的基础上,开展了作用力阈值感知基础实验和三维虚拟物体识别实验。 实验结果表明,两种三维虚拟物体的识别实验成功率 分别为 85. 7% 和 71. 4% ,有效验证了本文所设计力触觉再现方法的有效性。     

外加磁场对磁流体润滑油膜轴承的影响

为了研究磁流体润滑油膜轴承内磁场的分布情况,分别通过永磁铁、螺线管及亥姆赫兹线圈对其施加3种不同形式的外磁场。通过磁场二维实体有限元模型的数值仿真,分析在3种模型下磁流体润滑油膜轴承的磁场分布特性,并比较磁场在油膜区的分布情况。结果表明,永磁铁模型的磁场主要分布在永磁铁、油膜、轴承座以及靠近磁铁的轧辊部分,螺线管模型的磁场主要分布在油膜、轴承座以及靠近磁铁的轧辊部分,亥姆霍兹线圈模型的磁场主要分布在线圈以及油膜的端部;3种模型在油膜区磁场分布沿轴向均呈现中间小、两端大的不均匀现象,且具有端部效应;永磁铁模型和螺线管模型在油膜区磁场沿径向分布均匀,亥姆霍兹线圈模型沿径向分布不均匀。     

Design and fabrication of a novel polishing tool for finishing freeform surfaces in magnetic field assisted finishing (MFAF) process

Surface finish is a critical requirement for different applications in industries and research areas. Freeform surfaces are widely used in medical, aerospace, and automobile sectors. Magnetic field assisted finishing process can be used very efficiently to finish freeform surfaces. In this process, magnetorheological fluid is used as the polishing medium and permanent magnet is used to control its rheological properties to generate finishing force during polishing. To avail sufficient magnetic field in the finishing zone, it is necessary to design an optimum polishing tool. In the present study, a specially designed polishing tool is designed using a finite element based software package (Ansys Maxwell^®) based on Maxwell equations. At first, dimension of the permanent magnet is determined for designing optimum tool geometry. After that, dimension and configuration of the magnet fixture are optimized. A special type of metal named mu-metal which is a nickel-iron based alloy is selected for magnet fixture due to its magnetic-field shielding property. Mu-metal directs the magnetic flux lines in such a way that in the finishing zone the magnetic flux can be concentrated on the workpiece surface required for finishing. Also, the Mu-metal magnet fixture shields the magnetic field from outside environment so that MR fluid as well as any surrounding magnetic materials do not stick to the polishing tool. Experiments are carried out to validate the Maxwell simulation results to compare the magnetic flux distribution on the workpiece surface which shows good agreement between them. Also, finishing of flat titanium workpieces are carried out and it is found that the novel polishing tool has the capability to finish the workpieces in the nanometer range.     

被动式永磁阻尼器设计中磁转矩的工程计算

介绍了2种计算被动式永磁阻尼器磁转矩的工程方法,即高斯定理法和磁场有限元法。通过具体模型对比了2种方法的计算特点,并使用有限元软件Ansoft分析了永磁阻尼器各参数对输出的磁转矩的影响。用Ansoft仿真与实际测试结果进行了对比,验证了有限元法有较好的计算精度,适合在工程实际中推广。     

一种基于复杂永磁体阵列的悬浮式振动能量采集器的精确模型及验证

为提高振动能量采集器的输出性能和工作频带，基于永磁体阵列和多自由度器件受到广泛关注。然而这类器件存在磁场分布复杂，动态特性难以模拟等问题。以一种基于复杂永磁体阵列的可调频磁悬浮振动能量采集器为研究对象，建立器件解析模型和有限元模型的联合分析模型，理论模型显示系统具有非线性振动特性，其动力学模型可简化为Duffing方程形式，并通过有限元模型简化了对非线性系统的分析。利用COMSOL有限元仿真研究器件磁场分布、非线性磁力特性，分析磁力和线圈位置对器件输出特性的影响。搭建测试平台对研制的可调频磁悬浮振动能量采集器进行试验表征，以验证联合分析模型。试验结果表明，在20～35 mm的固定磁铁间距离变化范围内，器件谐振频率变化范围为8.6～13.1 Hz，0.35g加速度下输出电压峰峰值为352.9～658.2 mV，联合分析模型与试验之间具有一致性。     

永磁同步电机的变频调速研究

无励磁损耗和自身体积较小是永磁同步电机的一大优势所在.本论文的主要目的是永磁同步电机进行建模与分析,基于ANSYS Maxwell建立外转子永磁同步电机的有限元仿真模型,并基于该模型对电机磁场及各项电磁性能进行仿真计算与分析,已达到对永磁同步电机变频调速研究的需求,对电机进行建模与分析.确定电机参数包括性能指标要求、定...     

磁悬浮飞轮用永磁偏置磁轴承漏磁分析

磁悬浮飞轮用永磁偏置磁轴承的定转子气隙间存在漏磁现象,为了准确计算漏磁的大小,从而精确地对磁轴承进行磁路设计,利用有限元法对该现象进行了分析.通过ANSYS软件针对一台磁悬浮飞轮样机用径向磁轴承的磁场分布进行分析,提出了一种等效气隙漏磁系数的计算方法,得到样机用磁轴承的漏磁系数.样机试验结果表明,用这一方法计算得到的漏磁系数进行磁轴承参数设计及性能分析具有足够的精度,能够满足实际工程需要.