An insight into the flexible drive mechanism in short cylinder ultrasonic piezoelectric vibrator.

Abstract

In this study, a resonant type piezoelectric vibrator for driving a flexible body is proposed and its driving principle is discussed. The flexible body driven in this article is rigid in the longitudinal direction and flexible in the transverse direction, such as in metal straps and metal wires. The exciting signals used in the piezoelectric transducer in the horizontal and vertical directions are both sinusoidal signals, possessing a phase shift of π/2. Two third-order orthogonal bending in-plane modes of the same frequency were effectively excited, and an elliptic motion formed on the end plane of the vibrator toothed structure. A flexible body was then effectively driven by friction under a certain amount of tension. The proposed vibrator was designed using the finite element method, and the flexible drive models were established, while the output force in the contact friction was analyzed. The vibration characteristics of the vibrator were tested in order to obtain the resonance frequencies and responses. An experimental system was then established to test the mechanical output characteristics. The results demonstrate that the difference in thickness, tension force, and surface roughness between the flexible bodies confer great influence on driving. With a thickness of 0.01 mm, 0.02 mm, and 0.03 mm, the flexible metal strap velocity was found to be 24 mm/s, 43.64 mm/s, and 10.43 mm/s under the corresponding proper tension, smooth surface, and voltage of 200Vp-p, respectively.