Control method for drive of ultrasonic motor

Abstract

Abstract PURPOSE:To control the speed of drive of a moving body by setting amplitude by axial vibrations and varying amplitude by drive vibrations in the torsional direction, etc. CONSTITUTION:An annular type electrostrictive element 1 with a central hole divided into four fanwise is tied integrally by first and second metallic members 6, 8 and a bolt, thus constituting a vibrator 10. A rotor 12 is contact-bonded by pressure by a bolt 22 screwed to a female screw 21 formed onto the central axis of an output end surface 11 in the vibrator 10. When the rotor 12 is contact-bonded with the output end surface 11 at that time, axial amplitude is kept constant by controlling axial amplitude, torsional amplitude and relative phase, and the number of revolution is controlled by torsional amplitude. Consequently, axial amplitude (voltage of an axial drive power) is set so that abnormal vibrations are removed and maximum torque is acquired, and fixed. Only the voltage of a torsional drive power is varied and only amplitude by said torsional vibrations is altered, thus controlling the speed of drive for the rotor 12.

Inventors

• 👤 Shoji Mishiro
• 👤 三代　祥二

Bibliographic Details