Ultrasonic linear motor using surface acoustic waves

摘要

The first success in the operation of an ultrasonic linear motornat HF band driving frequency using the Rayleigh wave is described. Thensubstrate material is a 127.8° Y-cut LiNbO3 wafer whosendiameter is three inches. Four interdigital transducers (IDT's) arenarranged to excite x- and y-propagation waves in both directions. Thendimensions of the IDT are 25 mm aperture size, 400 Μm pitch, 100nΜm strip width, and 10 pairs. The operation area is about 25 mmnsquare, The driving frequency is about 9.6 MHz in the x direction andnabout 9.1 MHz in the y direction. The most important point of thensuccess is the shape of the contact surface and slider materials. Fornthe contact materials, small balls about 1 mm in diameter are introducednto obtain sufficient contact pressure around 100 MPa. The use of rubynballs, steel balls, and tungsten carbide balls is investigated. Eachnslider has three balls to enable stable contact at three points. Thenmaximum transfer speed is about 20 cm/s. The transfer speed isncontrollable by changing the driving voltage