Elastic friction drive of surface acoustic wave motor
Elastic friction drive of surface acoustic wave motor
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DOI：
10.1016/s0041-624x(02)00451-1
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发表时间：
2003-06-01
期刊：
影响因子：
4.2
通讯作者：
Asai, K
中科院分区：
文献类型：
--
作者：
Kurosawa, MK;Itoh, H;Asai, K
本文讨论了弹性变形控制对表面声波电机获得大输出力的重要性。通过对滑块施加预载荷，使定子和滑块表面在几十纳米范围内发生变形。根据SAW的法向振动位移幅值，存在适当的法向变形。通过适度的变形，SAW电机的输出力增大到10 N左右，空载速度为0.7 m/s。为了产生这种性能，传感器重量和滑块尺寸仅为4.2 g和4 x 4 mm(2)。通过行波传播，SAW器件表面粒子作椭圆运动。由于椭圆运动的幅值为10或20 nm量级，因此滑块的接触条件非常关键。为了控制滑块与定子的接触条件，即滑块与定子表面的纳米级弹性变形，在滑块表面制作了大量的投影。投影直径20毫米。在静力状态下，采用有限元方法计算了弹性变形和应力。从计算结果和仿真结果来看，考虑到波峰是扭曲的，因此弹性对摩擦驱动条件有影响。计算了定子表面在初始位置投影下的弹性变形。在4 × 4mm2的正方形区域内，滑块有1089到23409个投影。压差与接触压力无关。然而，尽管投影密度不同，但输出力取决于凹陷。从电机输出功率的角度来看，适当的降压与投影密度无关。在25 nm凹陷处，输出力和输出功率最大。该抑制值与定子换能器的振动位移幅值基本一致。(C) 2002 Elsevier Science B.V.版权所有
Importance of elastic deformation control to obtain large output force with a surface acoustic wave (SAW) motor is discussed in this paper. By adding pre-load to slider, stator and slider surfaces are deformed in a few tens nanometer. Appropriate deformation in normal direction against normal vibration displacement amplitude of SAW existed. By moderate deformation, the output force of the SAW motor was enlarged up to about 10 N and no-load speed was 0.7 m/s. To produce this performance, the transducer weight and slider size were only 4.2 g and 4 x 4 mm(2).By traveling wave propagation, surface particles of the SAW device move in elliptical motion. Due to the amplitude of the elliptical motion is 10 or 20 nm order, the contact condition of the slider is very critical. To control the contact condition, namely, the elastic deformation of the slider and stator surface in nanometer order, a lot of projections were fabricated on the slider surface. The projection diameter was 20 mum. In static condition, the elastic deformation and stress were evaluated with the FEM analysis. From this calculation and the simulation result, it is consider that the wave crest is distorted, hence the elasticity has influence on the friction drive condition.Elastic deformation of the stator surface beneath the projection from the initial position were evaluated. In 4 x 4 mm 2 square area, the sliders had from 1089 to 23,409 projections. Depression was independent to the contact pressure. However, the output force depended on the depression although the projection density were different. From the view point of the output power of the motor, the proper depression was independent to the projection density. Around 25 nm depression, the output force and output power were maximized. This depression value was almost same as the vibration displacement amplitude of the stator transducer. (C) 2002 Elsevier Science B.V. All rights reserved.