Energy circulation methods for surface acoustic wave motor
Energy circulation methods for surface acoustic wave motor
复制标题
声表面波电机的能量循环方法
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
T. Higuchi
中科院分区：
文献类型：
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作者：
K. Asai;M. Kurosawa;T. Higuchi
提高表面声波电机的效率对实现其商业化具有重要意义。在本研究中，表面波的能量以前没有被有效地用于驱动滑块，但被消耗在吸声材料中，现在通过两种技术进行循环，从而有效地激发表面波。用能量循环法进行了表面声波马达的试制。证实了行波实际上是可以激发的。此外，通过与不采用能量循环方法时的驱动性能的比较，证明了能量循环方法的有效性。《威利期刊》2003年第3期，87(2)：10-19,2004；在线发表在《威利国际科学》(www.intercience.wiley.com)上。DOI 10.1002/ecjc.10132关键词：声表面波；执行器；能量循环；更高效率；微机械。1.声表面波马达是一种在驱动力、速度、驱动精度和能量密度方面都具有优势的执行器。此外，由于声表面波器件的定子和硅基滑块是由MEMS领域培育的微机械技术制造的，因此该器件的可靠性和重复性都很好。然而，到目前为止，研究实现的表面声波电机的效率基本上不到1%。因此，提高效率对商业化具有重要意义。声表面波马达的效率可以从两个方面考虑。一个是从瑞利波的振动能量到滑块输出的转换效率。另一个是将输入电能转换为驱动滑块的瑞利波的振动能量的效率。第一项取决于滑块的接触面形状和接触条件，通过改善定子与定子基板之间的接触表面积和优化预紧力[1，2]来提高滑块的输出。第二项取决于定子基板的材料和设计。在迄今为止所研究的表面声波马达中，只有一小部分输入能量被用于驱动滑块，其余的能量被消耗在吸振器中。为了有效地驱动滑块，有必要循环这些迄今浪费的能量[3]。Tojo和他的同事报道了一种表面声波电机的能量循环方法[4]。在该报告中，提出了一种在定子衬底上使用两个驱动IDT和四个单向电极进行能量循环的方法。通过向两个驱动叉指换能器提供相差90°的输入信号，确认了驻波比为1.6的行波的激发。然而，到目前为止还没有关于成功驱动能量循环表面声波马达的报告讨论了它的设计。日本威利期刊社，Inc.，第三部分，第87卷，2004年第2期
SUMMARY It is important to improve efficiency of surface acous-tic wave motors in order to achieve their commercialization.In the present research, the energy of the surface wave,which has previously not been used effectively for drivingthe slider, but been consumed in sound-absorbing materials,is now circulated by two techniques, so that the surfacewave is excited efficiently. Trial fabrication of surfaceacoustic wave motors using the energy circulation methodsis carried out. It is confirmed that the traveling wave canactually be excited. In addition, the effectiveness of theenergy circulation method is demonstrated by comparisonof the driving performance with that in the absence ofenergy circulation methods. © 2003 Wiley Periodicals,Inc. Electron Comm Jpn Pt 3, 87(2): 10–19, 2004; Pub-lished online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10132 Key words: surface acoustic wave; actuator; en-ergy circulation; higher efficiency; MEMS. 1. Introduction Surface acoustic wave motors are a type of actuatorsthat are superior in terms of driving force, speed, drivingprecision, and energy density. Further, since the stator ofthe surface acoustic wave device and the silicon-basedslider are fabricated by micromachine techniques cultivatedin the MEMS field, the reliability and reproducibility of thedevice ar e excellent. However, the efficiency of the surfaceacoustic wave motors realized by research up to this timeis essentially less than 1%. It is therefore important forcommercialization to improve the efficiency. The efficiencyof the surface acoustic wave motors can be considered fromtwo aspects. One is the efficiency of conversion from thevibration energy of Rayleigh waves to the output at theslider. The other is the efficiency of conversion of the inputelectric energy to the vibrating energy of Rayleigh wavesused for driving the slider. The first item depends on thecontact surface shape and the contact condition of the slider.The slider output can be improved by improving the contactsurface area between the stator and the stator substrate andoptimization of the preload [1, 2]. The second item dependson the material and design of the stator substrate. In thesurface acoustic wave motors studied to date, only a slightportion of the input energy is used for driving of the slider.The remaining energy is consumed in the absorber. In orderto drive the slider efficiently, it is necessary to circulate thishitherto wasted energy [3].A method of energy circulat ion for the surface acous-tic wave motor has been reported by Tojo and colleagues[4]. In that report, a method for circulating the energy withtwo driving IDTs and four unidirectional electrodes on thestator substrate is presented. By providing input signalswhose phase difference is 90° to two driving IDTs, excita-tion of a traveling wave with a standing wave ratio of 1.6 isconfirmed. However, no report has yet reported success indriving an energy circulation surface acoustic wave motoror discussed its design.© 2003 Wiley Periodicals, Inc.Electronics and Communications in Japan, Part 3, Vol. 87, No. 2, 2004