PIEZOELECTRIC CONVEYING DEVICE

摘要

A piezoelectric sheet conveying device (100) of a linear contact type contains a pair of rollers (105) and (140) supporting the sheet (101) therebetween. The first roller (140) is driven by a piezoelectric vibrator (120) forming a contact line between the edge insert (125) of the vibrator (120) and the outer surface of the first roller (140). The vibrator (125) is urged against the first roller (140) by a bias spring (130). The hardness of the edge insert (125) of the vibrator (120) is about 5x10<7> N/cm<2> and much higher than the hardness of the first roller (140) being in turn about 2x10<6> N/cm<2>. As a result, elastic compressions of the first roller (140) are achieved during periodic elongations of the vibrator (120) and engagements of the first roller (140) surface. A microgroove is formed along the contact line between the vibrator (120) and the first roller (140) which transmits the rotational torque to the first roller (140) and advances the sheet (101) in a predetermined direction. Subsequent contraction of the vibrator (120) restores the outer surface of the first roller (140) to its initial shape. Both the first roller (140) and the vibrator (120) can be made as laminated structures to achieve respectively correct composite hardness and reduce the driving voltage.