Piezoelectric actuator based on two bending-type Langevin transducers

Abstract

Langevin-type piezoelectric transducers are widely used for different industrial applications such as high-accuracy positioning, ultrasonic welding, bonding, drilling, etc. Usually Langevin-type transducers operate at longitudinal mode by employing d33 vibrations of piezoceramic elements. A novel design of piezoelectric actuator based on two bending-type Langevin transducers is introduced. Two half-wavelength transducers are connected by a special aluminum plate. Piezoceramic rings with two-directional polarizations are used for bending oscillation excitation. An input voltage with phase shifted by π/2 on different transducers is applied. The forward and backward elliptical motion of the contact tip is controlled by changing phases of electric signals on different transducers. A numerical simulation was carried out to investigate the trajectories of contact point motion and to validate the operating principle of the actuator. Experimental prototype of the piezoelectric actuator was fabricated, and the measurements of driven tip movements and mechanical output were performed. The results of numerical and experimental analysis are discussed.