薄膜型超磁致伸缩微执行器的研究现状

超磁致伸缩薄膜是一种性能优良的新型微驱动元件,文章介绍了超磁致伸缩薄膜驱动的原理,综述了薄膜型超磁致伸缩微执行器的开发和最新研究成果,重点介绍了薄膜型超磁致伸缩微执行器在微流体控制系统、线性超声微马达及微小型行走机械中的应用,并对超磁致伸缩薄膜的微执行器中的应用进行了展望。     

超磁致伸缩微移动机器人

日本名古屋大学教授福田敏男和新井史人等开展了超磁致伸缩元件的研究工作,他们利用稀土类磁性材料的磁致伸缩特性,在室温下获得形变量大10~(-3)量级的结果.如果改变磁场,磁体就会产生形变的磁性材料称之为磁致伸缩材料,虽然磁致伸缩元件形变位移量很小,但是,由于外部的交流产生磁场变化,因此可用非接触方式使元件产生形变位移动,具有不用导线来作驱动的工作特点,磁致伸缩效应较大的超磁致伸缩元件产生形变位移,过去开发试制若干管内移动机器人可用于管内检查、修理工作,但是,为了使致动器驱动,电源供电缆处理成为问题,而超磁致伸缩驱动器不需要电缆,其形状适宜可做     

超磁致伸缩材料及其应用

介绍了超磁致伸缩材料具有高磁致伸缩应变λ，能量转换效率高、工作频带宽、频率特性好；稳定性好、可靠性高，其磁致伸缩性能不随时间而变化，无过热失效等特点；开发出的TbxDyt（1-x）Fe，合金，在较低的外磁场下就能达到超磁致伸缩效果，并对TbFez，DyFe2，Tb0.3Dy0.7Fe2（Terfenol-D）做了特性对比；超磁致伸缩材料在声频和超声技术方面广阔的应用前景，超磁致伸缩材料的应用及研究对发展声纳技术、水声对抗技术、海洋开发与探测技术将起到关键性作用。     

基于单片机的磁致伸缩材料性能测量系统开发

磁致伸缩材料是构成压力、温度、湿度以及液体黏度和密度等多种传感器的关键材料,材料本身的测量技术对其应用拓展至关重要。介绍了基于单片机的磁致伸缩系数测量系统的开发状况,并设计了一款磁致伸缩材料共振频率的测量系统,该系统对于磁弹性传感器的开发与应用具有实用意义。     

超磁致伸缩微位移驱动器的研究

新型超磁致伸缩材料ＴｂＤｙＦｅ具有输出力大、位移分辨力高及位移范围大等特点,将其应用于微位移驱动器中,将极大提高驱动器的性能指标,从而推动超精加工技术的发展。文中介绍了应用超磁伸缩材料研制的驱动器的结构及性能,并建立磁－机械耦合西式,以利于超磁致伸缩器件的研究及设计。     

基于功率MOSFET的超磁致伸缩执行器驱动电源

在分析超磁致伸缩材料的驱动特性及超磁伸缩执行器驱动电源特点的基础上,采用连续调整型恒流源的原理,并选用功率MOSFET作为功率放大元件,研制出－3－＋3A连续可调的高精度超微致伸缩执行器驱动电源。实际测试的结果表明其性能良好,可以满足驱动超微致伸缩材料的要求。     

高压氧治疗29例一氧化碳中毒致迟发脑病的效果分析

论述了超磁致伸缩材料在电液控制元件中的应用研究现状,基于超磁致伸缩材料的特点和未来航空航天领域对高频大流量伺服阀的迫切需求,提出了一种由超磁致伸缩执行器驱动的新型射流伺服阀的结构,分析了其工作原理与特点,同时对该新结构伺服阀涉及的温度控制、热补偿、预压力施加与零位调节与驱动磁场均匀化等关键技术进行了详细分析并给出了具体实施方法.     

Fe85Ga15合金的电子显微结构研究

磁致伸缩材料广泛应用于各种各样的传感器和伺服机构器件,Fe-Ga合金以其作为磁致伸缩材料的潜在应用前景已经引起研究人员的注意。Fe-Ga合金的磁致伸缩效应很强,归因于晶体中存在着Ga原子的不对称形状团簇,其导致的四方格子结构在Fe-Ga合金的磁致伸缩特性中起了关键的作用。     

磁致伸缩效应光纤微分干涉电流传感器

基于磁致伸缩效应，利用微分干涉仪，设计了一种光纤电流传感器，可用于高精度，高灵敏度电流和磁场的测量，分析了用磁致伸缩效应实现光纤电流传感器的原理，建立了基于磁致伸缩效应传感头的数学模型，并通过实验对光纤电流传感器的输入－输出特性，直流偏置特性和精确度等进行了研究，在8－200A的电流测量范围内，测量比差约为0．5％。     

磁性薄膜磁致伸缩效应及传感器的应用

磁性薄膜的磁致伸缩效应是磁性材料中普遍存在的现象，是磁性薄膜应力各向异性的主要表现。文中对磁性薄膜的磁致伸缩效应进行了理论分析与计算，并就磁致伸缩位移传感器介绍了磁致伸缩效应的应用原理，给出了其具体应用的例子。     

A hybrid inchworm linear motor

A hybrid linear motor that produces precise resolution with long travelling distance under inchworm motion principle is developed. The motor consists of one push and two clamping devices. The clamping device is innovated using multistack piezoelectric actuators with displacement amplifier since the displacement generated from multistack actuator is not enough for clamping. To secure the large push load and displacement, Terfenol-D magnetostrictive material is used for the push device. Design process of the push and clamping devices is conducted to meet the performance of the motor. The clamping and push devices are assembled and a control sequence is applied. The performance of the inchworm motor is tested in terms of speed and force. The moving speed is increasing when the input frequency and current are increased. To make the performance stable, time tuning between the push and clamping devices signals is necessary. Some remarks on improving the performance of the motor are addressed.     

New design of hybrid-type self-bearing motor for small, high-speed spindle

A new structure of hybrid (HB)-type self-bearing motor is proposed for miniature spindle motors. The proposed design combines the HB-type self-bearing motor and HB active magnetic bearing in the common stator and rotor pair to generate large radial forces. First, the principle and theoretical background are introduced. Then, the air gap flux is analyzed by the finite element method, and radial forces for the proposed and standard-type HB self-bearing motors are compared. Finally, experiments are conducted to confirm the performance of the proposed motor. The motor can run at relatively high rotating speed with relatively high torque compared with its small size. The levitation is very stable and the motor indicates good performance for practical application.     

Comparative Assessment of Several Nutation Motor Types

A new type of pneumatic stepping motor, named a nutation motor, has been developed. By using a simple mechanism in a compact body, this motor can generate high torque. The nutation motor consists of three small linear pneumatic actuators and a gear-reduction mechanism that transforms their motion into rotation of the output shaft. Driving each pneumatic actuator sequentially with pneumatic digital signals results in nutation of the input bevel gear, which causes the output shaft to rotate. In this paper, the structure, working principle, and theoretical characteristics of a pneumatic nutation motor are presented. The design and fabrication of five prototype models and the results of experimental evaluations are also reported in detail. The prototype motors range in size from 10 to 50 mm in diameter and from 11.5 to 49 mm in length. It was found that the torque/volume ratios of the pneumatic nutation motors were about 2–29 times larger than those of a typical conventional electromagnetic geared motor.      

一种新型驻波直线超声电机的研究

所叙述的一种新型驻波直线超声电机,它利用单相信号激发出动子的一阶弯曲模态,完全不同于一般直线型超声电机利用纵－弯或弯－弯复合模态。文中详细研究了适用于自振荡电路来驱动的该电机的原理、齿的运动轨迹,用有限元分析了该电机动子的工作模态,并在实验上验证了上述理论的正确性。     

直线超声马达研究进展

简述了近十年来直线超声马达的研究进展,分析了超声马达在结构设计和摩擦驱动等方面的关键问题。分析表明,开发新型原理的超声马达方兴未艾,但接触型马达为目前直线马达的主要发展方向。本体结构简化、驱动性能增强、工作效率及稳定性提高,是超声马达结构设计时应考虑的目标和任务。但接触型直线马达正常工作过程就是定/动子间的高频冲击磨损过程,定动子间摩擦学设计至关重要。另外,装配预紧力、接触间隙和磨损过程等引起的非线性问题,在马达设计制造和使用维护中应给予关注。最后,探讨了马达使用性能及运行寿命的影响因素,并总结了直线超声马达工作过程中的能量损失缘由和噪声产生机理。     

Linear electric machines—A personal view

The history of linear motors is a history of shape. Once having departed from the cylindrical geometry of rotating machines, a wider world of three-dimensional design becomes possible. Linear induction motors dominate the field of linear drives to the same extent as does the rotary induction machine in relation to more complicated adjustable-speed motors. It is therefore thought appropriate to devote only one section to linear motors other than induction. A fairly full treatment of electromagnetic levitation is also included together with a treatment of oscillating machines. Perhaps the most important features are the division of electrical machines into two classes which are termed "magnetic" and "electromagnetic" and the "topological explosion" which is at present taking place in linear motor design. Some linear machines are already well established on a commercial basis but the vast bulk of recent inventions still remain to be exploited.     

Fe膜及磁场沉积对TbDy-Fe膜磁伸性能的影响

为了提高TbDv-Fe膜的低场磁敏性,采用离子束溅射沉积(IBSD)法制备TbDy-Fe超磁致伸缩薄膜,分别研究了纯Fe膜与TbDy-Fe单层膜、TbDy-Fe/Fe耦合多层膜的复合及磁场下溅射沉积对TbDy-Fe膜磁致伸缩性能的影响;用振动样品磁强计(VSM)测试薄膜磁滞回线,用电容位移测量仪测试薄膜悬臂梁自由端偏转量,并计算出磁致伸缩系数λ.结果表明,由IBSD法制备的纯Fe膜、TbDy-Fe单层膜、TbDy-Fe/Fe复合膜的易磁化轴均平行于膜面,TbDy-Fe/Fe复合膜在低场下的磁化强度与磁导率均高于TbDy-Fe单层膜(在100 kA/m时,TbDy-Fe/Fe复合膜的磁化强度比TbDy-Fe单层膜高173%).纯Fe膜分别与TbDy-Fe单层膜、TbDy-Fe/Fe耦合多层膜进行复合均可提高薄膜磁致伸缩性能;磁场下溅射沉积所得180 nm纯Fe膜 640 nmTbDy-Fe/Fe耦合多层膜,由于在其膜面内短轴方向产生感生磁各向异性,从而使磁致伸缩性能得到进一步的提高,在150 kA/m的磁场下它的λ值可达到650×10-6.     

Interaction of Trace Rare‐Earth Dopants and Nanoheterogeneities Induces Giant Magnetostriction in Fe‐Ga Alloys

The discovery of a tenfold increase in magnetostriction of Fe by alloying nonmagnetic Ga was a breakthrough in magnetostrictive materials. The large magnetostriction is attributed to tetragonal nanoheterogeneities dispersed in the bcc matrix. A further remarkable fivefold increase is achieved by trace rare earth doping (<1 at%) up to a value of ≈1500 ppm, more than 50 times that of pure iron. However, it remains a mystery why trace rare earth dopants can induce such giant magnetostriction. Here, it is found that interaction of rare earth dopants with the nanoheterogeneities produces the giant magnetostriction, through a combination of experimental studies, first‐principles calculation and phase field simulations. The dopants tend to enter the nanoheterogeneities, increasing their distortion thereby creating a larger tetragonal distortion of the matrix as well as increased magnetocrystalline anisotropy. A mesoscopic model is developed using phase field simulation showing that the bulk tetragonal distortion arises mainly from those nanoheterogeneities with fixed Ga‐Ga pairs parallel to the applied magnetic field. Increased tetragonal distortion of the doped nanoheterogeneities leads to further distortion of the matrix. The results deepen the understanding of heterogeneous magnetostriction, and will guide the search for new magnetic materials with giant magnetostriction.     

某空间气体监测仪热设计及试验验证

某空间气体监测仪结构布局紧凑,在较小尺寸空间内交错布置有8个镜头组件、11台电子设备内热源和2个电机。内热源数量众多,工作时间长,与镜头控温要求差别大,且1个电机为二维转动热源,这些特点给热设计带来挑战。为有效解决热控难题,采用了多种设计思路组合。基于热管理思路对监测仪各部组件热行为进行系统管理,以节省热控资源;基于间接热控思路对所处热环境复杂的光学镜头组件进行控温,提高其控温精度和温度稳定度;对转动电机则进行辐射冷却,避免在传热路径中引入挠性转动环节,以提高热控系统可靠性;并基于结构热控一体化设计,在结构上充分保证热设计各项需求。热平衡试验结果表明:高低温工况下,监测仪各部组件温度均满足指标要求,且整个寿命周期内,光学镜头温度稳定度较高,同一工况下光学镜头最大温度波动在1℃以内,实现了多热源复杂工作机制下光学镜头的高精度精密热控。