A novel type of hybrid ultrasonic motor using longitudinal and torsional vibration modes with side panels

A novel type of hybrid ultrasonic motor using longitudinal and torsional vibration modes is presented, which has four side panels uniformly distributed along the circumference of the stator cylinder. There is rectangle piezoelectric ceramics (PZTs) based on d31 effect bonded on both sides of each side panels, which can be used to convert the first bending vibration mode of the side panels into the second torsional vibration mode of the stator when the exciting voltage is applied. Meanwhile, there are rectangle PZTs based on d31 effect bonded on the surfaces of the stator cylinder between every two side panels, which can be used to excite the first longitudinal vibration mode of the stator. The simulation results using finite element method (FEM) software Workbench reveals the suitable polarization arrangement of PZTs and the final designed structure of the motor. The appearance size of the prototype is 28.2 mm×28.2 mm×68 mm, while the outer diameter of the stator cylinder is 20 mm. The major vibration and mechanical characteristics of the prototype have been measured. The working frequency of the prototype measured in experiment is around 43.12 kHz, which is consistent with the numerical results. When operating voltage of 350 Vp-p is applied, the no-load speed of the prototype is 103 rpm and the stalling torque is 48 mN·m

Flexible supporting and fixing method for hybrid ultrasonic motor using longitudinal and torsional vibration modes

A new flexible supporting and fixing method for hybrid ultrasonic motor using longitudinal and torsional vibration modes is presented. A motor base is used to support and fix the motor, which has dual concentric bearings in opposite shell sides and a fixing slot. The axis of the motor has two extended parts outside the both sides of the motor. Once the motor has been assembled completely, the two extended parts of the motor axis will be inserted into the concentric bearings, which support the motor and restrict several degrees of freedom (DOFs) of the motor, such as the translational DOFs along X and Y axes, the rotational DOFs around X and Y axes. The motor has a flexible fixing sheet which placed near the piezoelectric ceramics, and the flexibility of the fixing is discussed by analyzing the thickness and the foot length of fixing sheet. The fixing sheet is fixed on the fixing slot with glue, which restricts the translational DOF along Z axis and rotational DOF around Z axis of the stator. The experiment results show that there is little influence on the motor working performance by using this supporting and fixing method; the motor can work smoothly and steadily and the maximum speed of the motor can exceed 2000 r/min

An Analytical Model for a Twisted Beam Piezoelectric Ultrasonic Micromotor

An equivalent circuit, known as a Mason model, is proposed to characterize a novel ultrasonic motor in this study. This motor, which consists of a non-circular cross-section twisted beam and a piezoelectric element, generates coupled longitudinal-torsional vibration upon application of an electric field. The model predictions and experimental data are in good agreement. For example, under the condition of having input voltage of 100 Vpp, and driving frequency of 352.8 kHz, the model predicts a longitudinal velocity of 0.7 m/s compared to the experimental results of 0.65-0.75 m/s. The assumption is that the torsional velocity and longitudinal velocity are in a linear relationship; a proportionality coefficient K=0.259±0.012 is obtained through the experimental data by empirically fitting

Design of a Single and Dual Hybrid Piezoelectric Motors

In this paper, a new hybrid piezoelectric motor was developed. A range of degeneracy was found to obtain multiple choice of resonance frequency by adjusting the length of the elastic blocks neighboring to the longitudinal and torsional vibrators. A template was implemented in between the longitudinal and torsional vibrators to decrease the mutual vibration effect that effectively makes the calculated and actual driving frequency nearly close. Such configuration was instrumental to preserve the expected performance and reduce the trial-and-error design overhaul process of the elastic blocks. Moreover, a dual hybrid motor was easily formed by butting each stator of the two hybrid motors together with a rotor in the middle. Case studies of both single and dual hybrid motors are presented with both simulation and experimental results to demonstrate the structure design and the degeneracy approach. Besides the convenience of structurally combining two single hybrid motors to enhance the output, it was interesting to find out whether the proposed dual hybrid motor can significantly increase either the speed or torque by using different phase control methods. Therefore, using the dual hybrid motor provides a great advantage by providing an option for pursuing higher speed or larger torque output for certain application

A smart 3D ultrasonic actuator for unmanned vehicle guidance industrial applications

A smart piezoelectric ultrasonic actuator with multidegree of freedom for unmanned vehicle guidance industrial applications is presented in this paper. The proposed actuator is aiming to increase the visual spotlight angle of digital visual data capture transducer. Furthermore research are still undertaken to integrate the actuator with an infrared sensor, visual data capture digital transducers and obtain the trajectory of motion control algorithm. The actuator consists of three main parts, the stator, rotor and housing unit. The stator is a piezoelectric ring made from S42 piezoelectric material, bonded to three electrodes made from a material that has a close Characteristics to the S42. The rotor is a ball made from steel material. The actuator working principles is based on creating micro elliptical motions of surface points, generated by superposition of longitudinal and bending vibration modes, of oscillating structures. Transferring this motion from flexible ring transducer through the three electrodes, to the attached rotor, create 3D motions. The actuator Design, structures, working principles and finite element analysis are discussed in this paper. A prototype of the actuator was fabricated and its characteristics measured. Experimental tests showed the ability of the developed prototype to provide multidegree of freedom with typical speed of movement equal to 35 rpm, a resolution of less than 5μm and maximum load of 3.5 Newton. These characteristics illustrated the potential of the developed smart actuator, to gear the spotlight angle of digital visual data capture transducers and possible improvement that such microactuator technology could bring to the unmanned vehicle guidance and machine vision industrial applications

Piezoelectric actuator with traveling wave waveguide

A novel design of traveling wave piezoelectric actuator with a special waveguide is investigated in the paper. Actuator consists of cylinder type waveguide and piezo ceramic ring. Waveguide has conical hole inside. Such configuration of the waveguide allows increasing amplitudes of the traveling wave vibrations. Electrodes of piezoceramic ring are divided into four equal sections. Four electric signals with shifted phases by π/2 are used for the excitation. Numerical simulation was carried out to optimize the shape and dimensions of the waveguide and to maximize oscillation amplitudes at the contact surface of the waveguide. Mathematical model of the contact interface between stator and rotor was developed. A prototype piezoelectric actuator was made and experimental investigation was performed. Results of numerical and experimental investigation are discussed

A smart ultrasonic actuator with multidegree of freedom for autonomous vehicle guidance industrial applications

A piezoelectric ultrasonic actuator with multidegree of freedom for autonomous vehicle guidance industrial applications is presented in this paper. The actuator is aiming to increase the visual spotlight angle of digital visual data capture transducer. It consists of three main parts, the stator, rotor and housing unit. The stator is a piezoelectric ring made from S42 piezoelectric ceramics material, bonded to three electrodes made from a material that has a close Characteristics to the S42. The rotor is a ball made from stainless steel materials. The actuator working principles is based on creating micro elliptical motions of surface points, generated by superposition of longitudinal and bending vibration modes, of oscillating structures. Transferring this motion from flexible ring transducer through the three electrodes, to the attached rotor, create 3D motions. The actuator Design, structures, working principles and finite element analysis are discussed in this paper. A prototype of the actuator was fabricated and its characteristics measured. Experimental tests showed the ability of the developed prototype to provide multidegree of freedom with typical speed of movement equal to 35 rpm, a resolution of less than 5μm and maximum load of 3.5 Newton. These characteristics illustrated the potential of the developed smart actuator, to gear the spotlight angle of digital visual data capture transducers and possible improvement that such micro-actuator technology could bring to the autonomous vehicle guidance and machine vision industrial applications. Furthermore research are still undertaken to develop a universal control prototype, integrate the actuator with an infrared sensor, visual data capture digital transducers and obtain the trajectory of motion control algorithm

Piezoelectric ultrasonic servo control feed drive renovate electro-discharge machining system industrial applications and transfer the technology into a new era

This paper presents the state of art of the latest development in Electro-Discharge Machining (EDM) system technology. It covers the current and recent development using the electromagentic and piezoelectric ultrasonic servo control feed drive technology. The paper also demonstrates how the ultrasonic technology renovates the system and transfers its industrial applications into a new era. EDM process is one of the most common processes in automotive and aerospace industry. It is mainly used to machine and process alloys and very hard materials for key manufacturing components, such as film cooling holes for Turbine Blades, engine strip sheets, steel sheets for automotive industry, outer vehicle body, … etc. The EDM system that uses electromagnetic servo control feed drive has a number of teething issues and this indicated the necessity to employ a new technology that could overcome these issues and enhance the system level of precision, dynamic time response, machining stability, arcing phenomena and product surface profile. The research undertaken to evaluate both systems showed that the system recently developed using ultrasonic servo control feed drive has a clear improvement in system dynamic time response, stability, a notable reduction in arcing and short-circuiting teething phenomena. This has been verified through the inter-electrode gap voltage variation. The electron microscopic examinations into the machined samples using the ultrasonic system have also indicated a clear improvement in the surface profile of the machined samples

Design, Modeling and Performance Optimization of a Novel Rotary Piezoelectric Motor

This work has demonstrated a proof of concept for a torsional inchworm type motor. The prototype motor has shown that piezoelectric stack actuators can be used for rotary inchworm motor. The discrete linear motion of piezoelectric stacks can be converted into rotary stepping motion. The stacks with its high force and displacement output are suitable actuators for use in piezoelectric motor. The designed motor is capable of delivering high torque and speed. Critical issues involving the design and operation of piezoelectric motors were studied. The tolerance between the contact shoes and the rotor has proved to be very critical to the performance of the motor. Based on the prototype motor, a waveform optimization scheme was proposed and implemented to improve the performance of the motor. The motor was successfully modeled in MATLAB. The model closely represents the behavior of the prototype motor. Using the motor model, the input waveforms were successfully optimized to improve the performance of the motor in term of speed, torque, power and precision. These optimized waveforms drastically improve the speed of the motor at different frequencies and loading conditions experimentally. The optimized waveforms also increase the level of precision of the motor. The use of the optimized waveform is a break-away from the traditional use of sinusoidal and square waves as the driving signals. This waveform optimization scheme can be applied to any inchworm motors to improve their performance. The prototype motor in this dissertation as a proof of concept was designed to be robust and large. Future motor can be designed much smaller and more efficient with lessons learned from the prototype motor