A resonant single-wing bionic piezoelectric motor based on a biasing self-clamping mechanism.

In this study, a resonant single-wing bionic piezoelectric motor based on a biasing self-clamping mechanism inspired by dragonfly flight was designed, assembled, and tested. The main mechanism of the designed piezoelectric motor includes a mover (including a vibrator, clamping foot, bionic pedestal, etc.), a stator, and other auxiliary components. The clamping foot of the mover contacts the side of the stator to form a biasing self-clamping mechanism, which can achieve a clamping effect within half a cycle of the vibrator's resonant vibration. The piezoelectric plate on the vibrator receives a single harmonic excitation from the signal generator, causing the base plate to bend and distort. The base plate drives the clamping foot to move regularly, causing the mover to perform a linear motion. Moreover, repeated single harmonic excitations can realize the continuous movement of the mover. The structure of the piezoelectric motor was optimized using COMSOL6.0, which is a finite element analysis software. The first-order bending vibration of the vibrator was chosen as the working mode through finite element simulation, and an experimental platform was built. The performance of the prototype piezoelectric motor was tested and verified on the experimental platform. The final experimental data show that under the conditions of 300 Vp-p excitation voltage and 109 Hz driving frequency, the maximum no-load speed of the prototype reaches 6.184 mm/s, and the maximum load of the motor is 4 g.

Bidirectional motion characteristics of a single harmonic-driven self-clamping linear piezoelectric motor.

We propose a multimodal model to realize the bidirectional motion of a self-clamping linear piezoelectric motor driven by a single harmonic signal based on previous motor research. Compared with the previous version, only the characteristics of the drive signal need to be changed in the motor without changing any other conditions to excite multimode and achieve reverse movement. The finite element software COMSOL5.2 was used to simulate the mode of the motor. The prototype has a maximum output speed of 71.5 mm/s, a maximum traction of 0.9 N at a voltage of 220 Vp-p, a frequency of 536 Hz, and a preload of 2 N. The minimum resolution of 26.4 µm was achieved at no-load, a voltage of 120 Vp-p, and a preload of 0 N.

Novel piezoelectric rotary motor on the basis of synchronized switching control.

A novel piezoelectric rotary motor (PRM) on the basis of synchronized switching control was designed, fabricated, and tested to achieve high speed, high efficiency, and high torque. The new motor mainly consists of a vibrator working in the resonance state as the driving element of the PRM and a clutch working in the quasi-static state to control the shaft for unidirectional rotation. The finite element method software COMSOL Multiphysics 5.4 was used to design the structure of the motor and determine the feasibility of the design mechanism of the PRM. Moreover, an experimental setup was built to validate the working principles and evaluate the performance of the PRM. The prototype motor outputted a no-load speed of 7.21 rpm and a maximum torque of 54.4 N mm at a vibrator driving voltage of 120 Vp-p and a clutch driving voltage of 200 Vp-p. The motor achieved a net efficiency of 15.6% under the preload torque of 3 N mm. The average stepping angle of the motor with no-load was 0.068°, when the voltages applied to the clutch and the vibrator were 200 Vp-p and 120 Vp-p, respectively, with the frequency of 512 Hz.

Resonant-type piezoelectric linear motor driven by harmonic synthesized mechanical square wave.

In this study, a novel resonant piezoelectric linear motor driven by harmonic synthesized mechanical square waves was designed, fabricated, and tested. The motor consists of a stator, a mover, and auxiliary parts. Periodic square wave motions of the stator and the mover were generated by composing two sinusoidal resonant bending vibrations with a frequency ratio of 1:3. Piezoelectric plates were deformed with a certain regularity to drive the piezoelectric motor. The finite element method software COMSOL was used to design the structure of the motor. An experimental device was established to validate the working principle and evaluate the performance of the motor. The prototype motor reached the maximum no-load velocity of 22.5 mm/s with the stator driven voltage of 140 Vp-p and the mover driven voltage of 180 Vp-p for a base frequency. The maximum traction force of 3.8 N was obtained under a stator driving voltage of 140 Vp-p and a mover driving voltage of 100 Vp-p for the base frequency. The motor achieved a net efficiency of 12.2% with a load of 0.3 N.

Inertial piezoelectric linear motor driven by a single-phase harmonic wave with automatic clamping mechanism.

A novel, single-phase, harmonic-driven, inertial piezoelectric linear motor using an automatic clamping mechanism was designed, fabricated, and tested to reduce the sliding friction and simplify the drive mechanism and power supply control of the inertial motor. A piezoelectric bimorph and a flexible hinge were connected in series to form the automatic clamping mechanism. The automatic clamping mechanism was used as the driving and clamping elements. A dynamic simulation by Simulink was performed to prove the feasibility of the motor. The finite element method software COMSOL was used to design the structure of the motor. An experimental setup was built to validate the working principle and evaluate the performance of the motor. The prototype motor outputted a no-load velocity of 3.178 mm/s at a voltage of 220 Vp-p and a maximum traction force of 4.25 N under a preload force of 8 N. The minimum resolution of 1.14 µm was achieved at a driving frequency of 74 Hz, a driving voltage of 50 Vp-p, and a preload force of 0 N.