Dynamic Displacements for Electromechanical Integrated Electrostatic Harmonic Drive

2008 ◽  
Vol 3 (3) ◽  
Author(s):  
Lizhong Xu ◽  
Lei Qin
Keyword(s):  
Natural Frequencies ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Frequency Equation ◽  
Drive System ◽  
Harmonic Drive ◽  
Electromechanical Integrated ◽  
Analysis Package ◽  
Design And Manufacture ◽  
Flexible Ring

The electromechanical integrated electrostatic harmonic drive is a new drive system invented by authors. The dynamic displacements of the flexible ring for the drive have important influence on operating performance of the drive system. In this paper, the three dimensional dynamic equations for the drive system are presented. The mode function equations and the frequency equation for the drive system are derived. The natural frequencies and dynamic displacements of the drive system are obtained. Using a finite element method analysis package, ANSYS, the natural frequencies and vibrating modes of the flexible ring for the drive system are simulated. The simulation results are compared to the analytical results above. The research is useful in design and manufacture of the drive system and can be used to design dynamic performance of the drive.

scholarly journals Effects of Eccentricity on the Dynamic Behavior for Electromechanical Integrated Toroidal Drive

2013 ◽  
Vol 20 (2) ◽  
pp. 273-286 ◽  
Author(s):  
Lizhong Xu ◽  
Haifeng Li
Keyword(s):  
Dynamic Behavior ◽  
Natural Frequencies ◽  
Drive System ◽  
The Other ◽  
Dynamic Equations ◽  
Electromechanical Integrated ◽  
Drive Systems ◽  
Forced Responses ◽  
Design And Manufacture ◽  
Center Distance

In electromechanical integrated toroidal drive, eccentric center errors occur which has important influences on the dynamic behavior of the drive system. Here, the dynamic equations of the drive system with eccentric center are presented. Changes of the natural frequencies and vibrating modes along with eccentric center distance are analyzed. The forced responses of the drive system to eccentric center excitation are investigated. Results show that the eccentric center causes some natural frequencies to increase, and the other natural frequencies to drop. It also causes some vibrations to become weak, and the other vibrations to become strong. The eccentric center has more obvious effects on the dynamic behavior of the planets. The results are useful in design and manufacture of the drive systems.

An Electromechanical Integrated Harmonic Piezodrive System

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Lizhong Xu ◽  
Huaiyong Li
Keyword(s):  
Sliding Friction ◽  
Deformation Energy ◽  
Ultrasonic Motor ◽  
Drive System ◽  
Harmonic Drive ◽  
Operating Life ◽  
Output Torque ◽  
Electromechanical Integrated ◽  
Flexible Ring

An electromechanical integrated harmonic piezodrive system is proposed. The key of the proposed piezodrive system is the integration of the piezodrive principle with the harmonic drive and the movable tooth drive principles, which changes the sliding friction between the rotor and the vibrator into a rolling mesh. It can substantially increase the system's output torque, operating life, and efficiency. In this paper, the design of the drive system and its operating principles are presented. Under piezoelectric excitation, the deformation energy of the flexible ring was analyzed and the output torque of the drive system was calculated, revealing that the drive system produces a higher output torque than does a normal bar-type ultrasonic motor.

scholarly journals Effects of molecule force on free vibration for a micro electromagnetic harmonic drive system

2021 ◽  
Vol 22 ◽  
pp. 12
Author(s):  
Dan Zhao ◽  
Lizhong Xu ◽  
Yuming Fu
Keyword(s):  
Free Vibration ◽  
Lower Order ◽  
Natural Frequencies ◽  
Van Der Waals ◽  
Drive System ◽  
Van Der Waals Force ◽  
Vibration Modes ◽  
Harmonic Drive ◽  
Force Dynamics ◽  
Flexible Ring

In this paper, a micro electromagnetic harmonic drive system is proposed. Considering Van der Waals force, dynamics equation of the flexible ring for the micro drive system is deduced and resolved. Using the equations, the effects of the molecule force on the natural frequencies and vibration modes of the drive system are investigated. Results show that considering molecule force, natural frequencies of the flexible ring are reduced and its vibration modes are changed. For lower order modes, smaller clearance between the flexible ring and stator, smaller thickness of the flexible ring and larger radius of the flexible ring, the effects of the molecule force on the natural frequencies and vibration modes are more obvious.

Theoretical Analysis and FEM Simulation of Piezoelectric Vibrator Used in Ultrasonic EDM System

2013 ◽  
Vol 694-697 ◽  
pp. 3020-3024
Author(s):  
Hong Bing Wang ◽  
Zhi Rong Li ◽  
Chun Hua Sun
Keyword(s):  
Theoretical Analysis ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Model Analysis ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Piezoelectric Vibrator ◽  
Working Frequency

The dynamic performance of the piezoelectric vibrator used in ultrasonic EDM machine in natural frequencies has a great effect on machining precision. Firstly, Through theoretical analysis the dynamic characteristics of the piezoelectric vibrator is obtained. Then the three-dimensional model of the piezoelectric vibrator is constructed by using PRO/E software, and model analysis is carried by using FEM software. Through theoretical analysis and FEM simulation, the appropriate working frequency and mode of the piezoelectric vibrator was found, and the piezoelectric vibrator was fabricated. Experimented results show that the model analysis of frequency is accord with that of FEM.

scholarly journals Nonlinear Forced Response of Electromechanical Integrated Toroidal Drive to Coupled Excitation

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Lizhong Xu ◽  
Fen Wang
Keyword(s):  
Natural Frequencies ◽  
Forced Response ◽  
Drive System ◽  
Mesh Stiffness ◽  
Electric Excitation ◽  
Time Period ◽  
Electromechanical Integrated ◽  
Exciting Frequency ◽  
Mesh Parameter ◽  
Forced Responses

The electric excitation and the parameter excitation from mesh stiffness fluctuation are analyzed. The forced response equations of the drive system to the coupled excitations are presented. For the exciting frequencies far from and near natural frequencies, the forced responses of the drive system to the coupled excitations are investigated. Results show that the nonlinear forced responses of the drive system to the coupled excitations change periodically and unsteadily; the time period of the nonlinear forced responses depends on the frequencies of the electric excitation, the mesh parameter excitation, and the nonlinear natural frequencies of the drive system; in order to improve the dynamics performance of the drive system, the frequencies of the electric excitations should not be taken as integral multiple of the mesh parameter exciting frequency.

The Three-Dimensional Dynamics for Toroidal Drive

2012 ◽  
Vol 562-564 ◽  
pp. 536-539
Author(s):  
Li Zhong Xu ◽  
Jin Liang Li ◽  
Ya Jun Li
Keyword(s):  
Natural Frequencies ◽  
Cone Angle ◽  
Three Dimensional ◽  
Drive System ◽  
Vibration Modes ◽  
Mesh Stiffness ◽  
Coupled Modes ◽  
Bearing Stiffness ◽  
Rigid Body Motions ◽  
Half Cone

In this paper, a model to simulate the dynamic behavior of the toroidal drive is developed. The three-dimensional dynamic model includes all six rigid body motions of the stator, worm, rotor and the planets. Using the model, the natural frequencies and vibration modes of the drive system are investigated. The vibration modes are classified into single modes and coupled modes. The single modes include planet mode, worm mode and stator mode. The vibration and frequency characteristics of different modes are obtained. The relation between modes and half cone angle of the planet tooth is discussed. The relation between vibrations and bearing stiffness is also discussed. When the bearing stiffness is about 10 times of the mesh stiffness, some vibration displacements of the drive system are quite small and can be neglected. Meanwhile, the dynamic equations for the drive system can be simplified.

scholarly journals Free Vibration for an Electromagnetic Harmonic Movable Tooth Drive System

2015 ◽  
Vol 9 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Yongli Liang ◽  
Lizhong Xu
Keyword(s):  
Natural Frequencies ◽  
Coupled System ◽  
Drive System ◽  
Vibration Modes ◽  
Electrical Parameters ◽  
Static Displacement ◽  
Coil Current ◽  
Coupled Dynamics ◽  
Flexible Ring ◽  
Electromechanical Coupled

The authors proposed an electromagnetic harmonic movable tooth drive system which is an electromechanical coupled system where the coupled dynamics controls its overall operating behavior. However, the coupled dynamics of such a system was not found in the literature. In this paper, an electromechanical coupled dynamics equation of the flexible ring subjected to electromagnetic force is presented. Using the equation, the natural frequencies and vibration modes of the flexible ring are investigated. The results show that the natural frequency of the drive system is affected by mechanical and electrical parameters among which, the coil current, the average static displacement of the flexible ring and the air gap have more obvious influence on the natural frequencies. The results are useful for the design and further study of the dynamics performance for the drive system.

Three-Dimensional Vibration Analysis of a Truncated Quadrangular Pyramid

1987 ◽  
Vol 54 (1) ◽  
pp. 115-120 ◽  
Author(s):  
T. Irie ◽  
G. Yamada ◽  
Y. Tagawa
Keyword(s):  
Vibration Analysis ◽  
Natural Frequencies ◽  
Ritz Method ◽  
Three Dimensional ◽  
Frequency Equation ◽  
The Body ◽  
Mode Shapes ◽  
Algebraic Polynomials ◽  
Transformation Of Variables ◽  
Unit Edge

An analysis is presented for the three-dimensional vibration problem of determining the natural frequencies and the mode shapes of a truncated quadrangular pyramid. For this purpose, the body is transformed into a right quadrangular prism with unit edge lengths by a transformation of variables. With the displacements of the transformed prism assumed in the forms of algebraic polynomials, the dynamical energies of the prism are evaluated, and the frequency equation is derived by the Ritz method. This method is applied to quadrangular pyramids in which the base is clamped and the other sides are free, and the natural frequencies (the eigenvalues of vibration) and the mode shapes are calculated numerically, from which the vibration characteristics arising in the pyramids are studied.

scholarly journals Vibration Analysis of a Two-Step Sine Movable Tooth Drive

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lizhong Xu ◽  
Jinan Yang
Keyword(s):  
Natural Frequencies ◽  
Vibration Mode ◽  
Fem Analysis ◽  
Element Model ◽  
Drive System ◽  
Single Element ◽  
Total System ◽  
Vibration Modes ◽  
System Vibration ◽  
Analysis Package

In this study, a 3D model of a two-step sine movable tooth drive is developed in the UG software. The finite element model (FEM) analysis package, ANSYS, is used to calculate the natural frequencies and vibration modes of the drive system. The results show that the first twenty natural frequencies can be classified into five families, including the total system vibration mode, single-element vibration mode, two-element vibration mode, three-element vibration mode, and four-element vibration mode. The effects of the system parameters on the natural frequencies and the vibration modes are investigated. The track amplitude, the movable tooth radius, the radius of the movable tooth rotation, and the number of movable teeth affect the natural frequencies and vibration modes of the drive system.

Differential planetary mechanism of reduction gear for robotic applications

2017 ◽  
Vol 232 (5) ◽  
pp. 799-803 ◽  
Author(s):  
Bumjoo Lee ◽  
Donghan Kim ◽  
Young-Dae Hong
Keyword(s):  
Three Dimensional ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Drive System ◽  
Reduction Gear ◽  
Prototype System ◽  
Harmonic Drive ◽  
Differential Motion ◽  
Gear Mechanism ◽  
Planetary Gear Mechanism

This study proposes a novel planetary gear mechanism composed of normal spur gears. Similar to a harmonic drive system, one pair of gears generates differential angular motion to achieve a high reduction gear ratio. While a harmonic drive system utilizes slightly different number of gear teeth between the flex spline and the circular spline to induce differential motion, a planetary gear mechanism with different gear modules is adopted for this purpose in the proposed system. Since the manufacture of special components like the wave generator and flex spline in harmonic drive system is not required here, the machinability and usability are improved. In addition, the mechanism can be achieved with a flat shape, which is crucial for various applications such as robotic systems. After the basic concept and three-dimensional design are introduced, the prototype system is presented.

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