Design and experimental performance of a low-frequency piezoelectric motor based on inertia drive

A low-frequency piezoelectric motor based on inertia drive is presented in this paper, which is composed of a stator section and a rotor section. The stator employs an asymmetric structure, which causes torsional vibration when it is driven by single-phase sine wave power. In this paper, we study the working mechanism and characteristics of the low-frequency piezoelectric motor through theoretical modeling and experimental testing. [Display omitted] •The driving unit of the piezoelectric motor employs an asymmetric structure, which can cause torsional vibration.•The piezoelectric motor can resonate at 50 Hz, so it does not require special power supply and has low working noise.•The inertia drive piezoelectric motor has obvious advantages like simple structure, easy miniaturization and low cost. The inertia drive piezoelectric motor generally employs an asymmetric waveform driving signal, and the power supply for generating such type of driving signal is complicated and costly. In order to simplify the driving power of the inertia drive piezoelectric motor, a low-frequency piezoelectric motor driven by a 50 Hz sine wave is proposed in this paper. We first analyze the working principle: the pressure between the rotor and the stator changes asymmetrically in one working cycle, driving the rotor’s one-way rotation. Then we establish the dynamic model of the system and study the influence of the pre-stress between the stator and the rotor on the output performance of the low-frequency piezoelectric motor. Finally, the prototype is made and tested for performance. Experiments show that the low-frequency piezoelectric motor resonates at a driving frequency of 50 Hz, where the amplitudes of the stator in the vertical direction and the rotational direction are 21 μm and 136 μm respectively. When the pre-stress between the stator and the rotor is 5 N, the motor speed reaches a maximum value of 4.3 r/min; when the pre-stress is 11 N, the torque of the motor reaches a maximum value of 0.29 Nm.