Application39 Ultrasonic motor using piezoelectric element

[General]
An ultrasonic motor is a type of motor that drives a rotor or a linear driven object using ultrasonic vibration.
Ordinary motors use a permanent magnet or coil to rotate the rotor, while ultrasonic motors use piezoelectric elements to generate ultrasonic waves.
Due to its high degree of design freedom, it is used to design interchangeable lenses for single-lens reflex cameras and mirrorless cameras.
In this example, we conducted piezoelectric harmonic analysis and confirmed that it was driven as a motor.

[Analysis]
Figure 1 shows the structure of the ultrasonic motor used this time.
The piezoelectric and metal are bonded together, and electrodes are periodically arranged on the surface of the piezoelectric. Set the phase regularly for each electrode.
The piezoelectric element expands or contracts depending on the direction of the potential when a potential difference is applied to the two terminals. The expansion and contraction generate ultrasound.
Piezoelectric analysis results are shown in Figure 2. As a result, it can be seen that the piezoelectric body vibrates ultrasonically and is driven as a motor.