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提出一种五自由度稳定悬浮的电主轴,由二自由度磁悬浮异步电机与三自由度轴向混合磁轴承实现五个自由度的稳定悬浮。其中,三自由度混合磁轴承采用四个定子磁极来控制轴向悬浮力与径向扭转力,可有效减少轴向长度。文中介绍了五自由度磁悬浮电主轴工作原理,建立磁悬浮异步电机和混合磁轴承的数学模型,并用电磁场分析软件welll5.0分析其磁场和悬浮力,验证电主轴的可行性,最后运用biatlab软件建立基于转子磁场定向的无轴承异步电机控制系统,仿真结果表明该控制方法可有效稳定控制电机。 相似文献
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提出一种新型的五自由度混合磁轴承支承高速电机系统,由径向二自由度混合磁轴承、径向-轴向三自由度混合磁轴承和高速电机构成.文中介绍混合磁轴承的结构和工作原理,二自由度混合磁轴承采用轴向充磁的环形永磁体提供偏置磁场,定子采用双片式八极结构,每片定子有四个凸极.三自由混合磁轴承集成径向和轴向磁轴承功能,采用径向充磁的环形永磁体提供径向和轴向偏置磁场.导出磁轴承的数学模型,给出详细的参数设计方法,最后采用Maxwell电磁场有限元分析软件对磁轴承的磁路和主轴受力情况进行分析.理论研究和有限元分析表明,这种五自由度混合磁轴承系统结构参数设计合理. 相似文献
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磁悬浮支承技术是目前世界上公认的高新技术之一。它在高档数控机床中可以作为高速机床电主轴和高速机床直线电机进给平台的支承技术。主动控制磁悬浮轴承(简称主动磁轴承A M B)是利用可控磁场力提供无接触支承、使转子稳定悬浮于空间且其动力学性能可由控制系统调节的一种新型 相似文献
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提出了一种5自由度混合磁轴承支承高速电机系统,由径向2自由度混合磁轴承、径向-轴向3自由度混合磁轴承和高速电机构成.2自由度磁轴承定子采用8极结构,4个是控制磁极,4个是嵌入永磁体的永磁磁极.3自由度混合磁轴承集成了径向和轴向轴承功能,采用径向充磁的环形永磁体提供径向和轴向磁轴承偏置磁场.文中介绍了混合磁轴承的结构和工作原理,导出了磁轴承的数学模型,给出了详细的参数设计方法,最后采用MAXWELL电磁场有限元分析软件对磁轴承的磁路和主轴受力情况进行了分析.理论研究和有限元分析表明:这种5自由度磁轴承系统结构参数设计合理. 相似文献
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为解决或降低传统直驱风力发电机系统的机械摩擦问题,以有效提高风能利用率,提出直驱风力发电机采用机械轴承和磁悬浮轴承集成支承技术,即采用机械轴承和径向-轴向三自由度混合磁轴承实现直驱风力发电机的集成支承。针对径向-轴向三自由度混合磁轴承,采用等效磁路法进行数学建模,并利用有限元分析软件对其进行参数设计与机理分析。在此基础上,构建了径向-轴向三自由度磁轴承试验平台,试验结果证明设计的径向-轴向三自由度磁轴承能够实现稳定悬浮。 相似文献
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为减小风力发电机的机械摩擦及减少其维护成本,降低风力发电机启动风速,减小旋转阻力矩,提高风能利用率,在垂直轴风力发电机中采用混合轴承支承,即风力发电机径向采用1个径向磁轴承和1个机械轴承支承,轴向采用一个轴向磁轴承来实现五自由度支承。针对轴向磁轴承,首先介绍了其结构及工作原理,然后采用等效磁路法建立数学模型,并按性能指标要求进行参数设计,然后用Ansoft软件对轴向磁轴承磁场及受力等进行分析验证,设计了轴向磁轴承控制系统,并用Matlab软件对磁轴承的控制系统进行了阶跃响应、起浮和扰动等仿真研究。研究结果表明:参数设计合理,控制系统够实现磁轴承可靠及稳定的悬浮。 相似文献
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Bing Tu Desheng Li Enhuai Lin Bin Luo Jian He Lezhi Ye Jiliang Liu Yuezhong Wang 《Frontiers of Mechanical Engineering in China》2010,5(4):446-449
Rotation magnetic beacons magnetic field strength is very important to drill parallel horizontal twin wells in steam assisted
gravity drainage (SAGD). This paper analyzes a small magnet with a diameter of 25.4 mm. At each end, there is a length of
12.6 mm with permanent magnet, and in the middle, there is a length of 78mm with magnetic materials. The magnetic field strength
generated by the magnetic material of 1J12, 1J50, and 1J79 is analyzed, respectively. ANSOFT software is used to simulate
the magnetic field strength generated by different magnetic materials above, which also be tested through experimental methods.
The comparison of the simulation and experimental results show that experimental and simulation results are basically consistent,
and the results can meet the specific requirements of engineering applications. 相似文献
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磁悬浮陀螺飞轮用隐式洛伦兹力磁轴承 总被引:2,自引:0,他引:2
针对磁悬浮陀螺飞轮用显式洛伦兹力磁轴承气隙磁密均匀性差的问题,提出了一种磁钢内置的隐式洛伦兹力磁轴承,并采用三维有限元法对两种方案的气隙磁密进行比较分析。隐式方案的气隙磁密在周向和纵向的变化率分别为0.8%和8.4%,远优于显式方案的15.0%和23.7%。利用磁场分割法对隐式方案的磁阻进行了区域分割,采用积分法精确计算各区域磁阻,建立了磁轴承磁路数学模型,得到了影响偏转电流刚度的关键结构参数,并基于有限元法对隐式方案形状及结构参数进行详细优化。结果表明,在不恶化气隙磁密变化率的前提下,优化前后绕组区域的最大磁密和最小磁密分别从0.404T和0.368T增加至0.464T和0.427T,增幅为14.6%和16.0%。根据优化结果研制了一台隐式洛伦兹力磁轴承,并进行了气隙磁密和偏转电流刚度实验测试,测试结果与设计结果相符,对洛伦兹力磁轴承的设计具有重要意义。 相似文献
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A controllable and variable magnetic field was got by improving the oil cup of a MS-800 four-ball tester. By this improved four-ball tester, the tribological properties of Mn0.78Zn0.22Fe2O4 magnetic fluid in the magnetic field were tested. The worn surfaces of the steel balls lubricated with 6 wt% Mn0.78Zn0.22Fe2O4 magnetic fluid under different magnetic fields were observed by using a scanning electron microscope (SEM), while the elemental compositions of the wear scars were analyzed by means of energy dispersive spectrometry (EDS). It was found that the Mn0.78Zn0.22Fe2O4 nanoparticles had a diameter about 20 nm. Under magnetic field, the 46# turbine oil containing 6 wt% Mn0.78Zn0.22Fe2O4 nanoparticles showed much better friction-reducing and anti-wear abilities compared with lubrication without magnetic field. The worn surface, lubricated by 6 wt% Mn0.78Zn0.22Fe2O4 magnetic fluid lubricated under the effect of magnetic field, is smooth and the plowing is almost disappeared. Moreover, it is found that 22 mT magnetic induction is the optimum magnetic induction. Form theory study we found that under the effect of magnetic field, the bearing capacity increasing with the increasing of magnetic induction. When the eccentricity is small, the side leakage is highly decreased. 相似文献
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G.S.A.M Theunissen 《Tribology International》1998,31(9):519-523
Many coatings are in use today for the wear protection of thin film heads. With the trend towards smaller head-media distances, the thickness of the coating has to diminish. In this paper some of these coatings: zirconia, chromium nitride, chromium oxide and diamond (+diamond-like carbon) will be discussed. It will be shown that the film hardness is influenced by the microcrystalline structure, the texture and the film stress. The film hardness shows a good correlation with the reciprocal wear coefficient. The wear resistance of the materials discussed increases in the order: zirconia, chromium nitride, chromium oxide, diamond. 相似文献
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B Meier J Kohlrautz J Haase M Braun F Wolff-Fabris E Kampert T Herrmannsdörfer J Wosnitza 《The Review of scientific instruments》2012,83(8):083113
A nuclear magnetic resonance apparatus for experiments in pulsed high magnetic fields is described. The magnetic field pulses created together with various magnet coils determine the requirements such an apparatus has to fulfill to be operated successfully in pulsed fields. Independent of the chosen coil it is desirable to operate the entire experiment at the highest possible bandwidth such that a correspondingly large temporal fraction of the magnetic field pulse can be used to probe a given sample. Our apparatus offers a bandwidth of up to 20 MHz and has been tested successfully at the Hochfeld-Magnetlabor Dresden, even in a very fast dual coil magnet that has produced a peak field of 94.2 T. Using a medium-sized single coil with a significantly slower dependence, it is possible to perform advanced multi-pulse nuclear magnetic resonance experiments. As an example we discuss a Carr-Purcell spin echo sequence at a field of 62 T. 相似文献
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数字磁罗盘的全姿态罗差补偿 总被引:2,自引:0,他引:2
针对现有磁罗盘罗差补偿方法成本高、效率低和全姿态补偿能力不足的问题,提出了一种基于几何变换的全姿态罗差补偿方法.首先,根据外磁干扰对磁传感器采样值的影响,建立了几何变换罗差补偿模型,将罗差补偿参数由12个减少到9个.其次,将牛顿法算子引入到粒子群算法中建立了混合粒子群优化算法,采用粒子群算法选取优化参数初始值,以牛顿法... 相似文献
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This paper describes a thrust bearing using a magnetic fluid lubricant under a magnetic field. The critical pressures of the bearing versus the magnitude of the magnetic flux densities have been investigated experimentally. It is shown that the critical pressures of the proposed bearing are larger than those of the normal lubricated bearing under high speeds. 相似文献
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Wang Zhaoxia Zhang Weimin Liu Hongguang 《Frontiers of Mechanical Engineering in China》2008,3(2):222-225
The magnetic leakage field distribution resulting from linear defects of a tube sample in the geomagnetic field is modeled
according to the magnetic dipole theory. The formula to compute the normal component of the weak magnetic field is deduced
based on the spatial distribution of the magnetic dipole. The shape and characteristics of the zero line (an important criterion
for magnetic memory testing) of the normal field is analyzed under different longitudinal magnetizations. Results show that
the characteristics of the zero line should be considered when the metal magnetic memory testing method is used to find and
locate the defect.
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Translated from Transactions of Beijing Institute of Technology, 2007, 27(147): 395–398 [译自: 北京理工大学学报] 相似文献