Multi-degree-of-freedom ultrasonic motors for mass-consumer devices

New approach to design active kinematic pairs, transforming resonant non-harmonic periodical vibrations into continuous motion is presented. The specifics of a piezoelectric motor utilizing this approach is that it can be made with limited size of arbitrary cross-section. Some examples of this type of piezomotor are presented, allowing creating miniature in-plane positioning systems and angular scanning systems. Examples of multi-degree-of-freedom piezomotors in mass-consumer devices are shown by “smart” toy prototypes made from standard LEGO™ construction blocks and mini figures.     

Driving concepts for bundled ultrasonic linear motors

Several positioning tasks demand translatory drive instead of rotary motion. To achieve drives that are capable, e.g., to drive the sunroof of a car or to lift a car’s window, multiple miniaturized motors can be combined. But in this case many other questions arise: The electromechanical behavior of the individual motors differs slightly, the motor characteristics are strongly dependent on the driving parameters and the driven load, many applications need some extra power for special cases like overcoming higher forces periodically. Thus, the bundle of motors has to act well-organized and at last controlled to get an optimized drive that is not oversized and costly.     

Fabrication,modelling and use of porous ceramics for ultrasonic transducer applications

Porous ceramics are of interest for ultrasonic transducer applications. Porosity allows to decrease acoustical impedance, thus improving transfer of acoustical energy to water or biological tissues. For underwater applications, the d_hg_h figure of merit can also be improved as compared to dense materials. In the case of high frequency transducers, namely for high resolution medical imaging, thick film technology can be used. The active films are generally porous and this porosity must be controlled. An unpoled porous PZT substrate is also shown to be an interesting solution since it can be used in a screen-printing process and as a backing for the transducer. This paper describes the fabrication process to obtain such materials, presents microstructure analysis as well as functional properties of materials. Modelling is also performed and results are compared to measurements. Finally, transducer issues are addressed through modelling and design of several configurations. The key parameters are identified and their effect on transducer performance is discussed. A comparison with dense materials is performed and results are discussed to highlight in which cases porous piezoceramics can improve transducer performance, and improvements are quantified.     

超声波电机速度特性测试技术研究

电机性能测试的离散数据中包含各种扰，必须对测试数据进行数字处理。文中用计算编程采集光电编码器脉冲值，并采用曲线拟合、数字滤波的方法对所测信号进行处理，得出电机运行特性曲线，为进一步改进超声波电机运行特性和提高控制的性能奠定基础。     

The design and characteristics of ring type linear ultrasonic motor for X-Y stage

In this paper, the linear ultrasonic motor is newly designed to apply for the actuator of X-Y stage, its vibration mode is analyzed by FEM software, and its characteristics are studied as a function of the inner diameter of the elastic body. As a result from FEM analysis, the stator simultaneously vibrates to radial and bending vibration mode. Based on the result, ring-type linear ultrasonic motors are fabricated according to its inner diameter and its resonant frequency is measured by impedance analyzer. As inner diameter increases, its resonant frequency and velocity decreases. When its inner diameter, input voltage and driving frequency are 10 mm, 20 Vpp and 68.6 kHz, the velocity of the moving body is about 100 mm/s.     

Properties of Cu,Ni, and V doped-LaCrO <Subscript>3</Subscript> interconnect materials prepared by pechini,ultrasonic spray pyrolysis and glycine nitrate processes for SOFC

The ceramic interconnect,La_0.8Sr_0.05Ca_0.15(Cr_{1 −x} , B_x)O₃ (B = Cu, Ni, V, x = 0.02, 0.1, 0.5) (LSCCB) powders were prepared by Pechini method, Ultrasonic Spray Pyrolysis (USP) and Glycine Nitrate Process (GNP). Nano sized powders were synthesized by GNP and their chemical compositions were confirmed by ICP analysis. The electrical conductivities of LSCCCu, LSCCNi, and LSCCV samples were 34 S/cm, 48 S/cm, and 22 S/cm at 800^∘C in air, respectively. Among the LSCCB powders, the LSCCNi sample shows highest relative density and electrical conductivity. In a low oxygen partial pressure, however, LSCCV sample was more stable. The perovskite phase of the composition LSCCV sample is of large practical interest for interconnects in SOFC because of the stability in low oxygen partial pressure.     

微机主变保护应用中的几个问题

从工程实际出发，分析了微机主变保护在应用中的几个问题，提出了相应的解决办法，保证了主设备的安全运行，提高了电网运行的可靠性。     

空间飞行器用锂离子蓄电池储能电源的研究进展

锂离子蓄电池由于具有高的比能量、低的热效应、无记忆效应等突出优点,将成为继镉镍蓄电池、氢镍蓄电池之后的第三代卫星用储能电源,国外已经开始在空间飞行器上应用锂离子蓄电池作为储能电源。介绍了新型锂离子蓄电池储能电源的反应机理、电池的研究进展及锂离子蓄电池在空间电源的应用情况。