scholarly journals Electromagnetic and Mechanical Characteristics Analysis of a Flat-Type Vertical-Gap Passive Magnetic Levitation Vibration Isolator

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Baoquan Kou ◽  
Yiheng Zhou ◽  
Xiaobao Yang ◽  
Feng Xing ◽  
He Zhang

In this paper, we describe a flat-type vertical-gap passive magnetic levitation vibration isolator (FVPMLVI) for active vibration isolation system (AVIS). A dual-stator scheme and a special stator magnet array are adopted in the proposed FVPMLVI, which has the effect of decreasing its natural frequency, and this enhances the vibration isolation capability of the FVPMLVI. The structure, operating principle, analytical model, and electromagnetic and mechanical characteristics of the FVPMLVI are investigated. The relationship between the force characteristics (levitation force, horizontal force, force ripple, and force density) and major structural parameters (width and thickness of stator and mover magnets) is analyzed by finite element method. The experiment result is in good agreement with the theoretical analysis.

2018 ◽  
Vol 10 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Yong Wang ◽  
Ruo-Chen Wang ◽  
Hao-Dong Meng

Inerter, which is defined as a two-terminal mechanical element, has the characteristic that the force generated at its two terminals is proportional to the relative acceleration between its two ends. Here, the inerter is used in the vibration isolation system; eight kinds of one-stage inerter-based vibration isolators are presented in this paper. Dynamic equations of eight kinds of one-stage inerter-based vibration isolators are established, the natural frequency is considered, and the dynamic response and transmissibility are obtained using the time domain analysis method or the Laplace-transformed method. Four performance indexes are defined to evaluate their isolation performance and compared with the linear vibration isolator (LVI). The best structural parameters of these one-stage inerter-based vibration isolators are determined using the H[Formula: see text] optimization method based on the fixed-point theory, which aims to minimize the maximum transmissibility. The results show that compared with the LVI, some kinds of one-stage inerter-based vibration isolators can offer a better isolation performance according to the four performance indexes. Furthermore, the best vibration isolator among these vibration isolators is determined by the four performance indexes.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1830
Author(s):  
Yiheng Zhou ◽  
Baoquan Kou ◽  
He Zhang ◽  
Lu Zhang ◽  
Likun Wang

The multi-degree-of-freedom high-precision positioning system (MHPS) is one of the key technologies in many advanced industrial applications. In this paper, a novel hyperbolic magnetic field voice coil actuator using a rhombus magnet array (HMF-VCA) for MHPS is proposed. Benefiting from the especially designed rhombus magnet array, the proposed HMF-VCA has the advantage of excellent force uniformity, which makes it suitable for multi-degree-of-freedom high-precision positioning applications. First, the basic structure and operation principles of the HMF-VCA are presented. Second, the six-degree-of-freedom force and torque characteristic of the HMF-VCA is studied by three-dimensional finite element analysis (3-D FEA). Third, the influence of structural parameters on force density and force uniformity is investigated, which is conducive to the design and optimization of the HMF-VCA. Finally, a prototype is constructed, and the comparison between the HMF-VCA and conventional VCAs proves the advantage of the proposed topology.


2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Kai Meng ◽  
Yi Sun ◽  
Huayan Pu ◽  
Jun Luo ◽  
Shujin Yuan ◽  
...  

In this study, a novel vibration isolator is presented. The presented isolator possesses the controllable stiffness and can be employed in vibration isolation at a low-resonance frequency. The controllable stiffness of the isolator is obtained by manipulating the negative stiffness-based current in a system with a positive and a negative stiffness in parallel. By using an electromagnetic device consisting of permanent magnetic rings and coils, the designed isolator shows that the stiffness can be manipulated as needed and the operational stiffness range is large in vibration isolation. We experimentally demonstrate that the modeling of controllable stiffness and the approximation of the negative stiffness expressions are effective for controlling the resonance frequency and the transmissibility of the vibration isolation system, enhancing applications such as warship stealth technology, vehicles suspension system, and active vibration isolator.


2013 ◽  
Vol 774-776 ◽  
pp. 168-171
Author(s):  
Qian Qian Wu ◽  
Rong Qiang Liu ◽  
Hong Hao Yue ◽  
Zong Quan Deng ◽  
Hong Wei Guo

Actuator based on Lorentz force exhibits excellent isolating performance with its non-contact characteristic, especially during frequency bandwidth below 5Hz. In this paper, mathematical model of the magnetic levitation actuator is constructed. In order to obtain better performance, parametric design of the structure of magnetic actuator is carried out and a multi-objective optimization method is proposed to maximize Lorentz force and minimize the mass of coil on the basis of genetic algorithm in the optimization process. A designing optimization program is developed, by which optimized parameters of magnetic actuator with maximal actuator force and minimal mass of coil can be identified to conduct experiment on ground. Compared with initial values in an instance, the optimized method is proven to be feasible and has the value of practical application.


Author(s):  
Kai Meng ◽  
Yong Gu ◽  
Jianhui Ma ◽  
Xidong Liu ◽  
Xiangqian Geng ◽  
...  

In this study, a novel negative stiffness spring is developed. The developed spring possesses the characteristics of the controllable stiffness and can be employed in vibration isolation system with a low resonance frequency. The controllable electromagnetic negative stiffness spring (CENSS) is obtained by the coaxial permanent magnets (PMs) and the circular current-carrying coils. The stiffness control is accomplished by changing the current in the coils. Furthermore, the mathematical model of CENSS is established, based on the filament method. According to the model, the relationship between the exciting current and the axial stiffness is obtained. Moreover, the influence of the structural parameters of CENSS on the magnetic force and the stiffness is analyzed. The results demonstrate that the thickness of PMs and the coils have the ability to adjust the range of the negative stiffness. Finally, performance experimental study of CENSS in the stiffness domain is carried out under different exciting currents and thicknesses. The experimental results have shown a good agreement with the model. It demonstrates that the performance of negative stiffness in CENSS can be controlled efficiently by the exciting current and optimized by the thickness.


Author(s):  

The ASONIKA-V software package, intended for the mechanical characteristics analysis of the cabinets, racks and blocks of radio-electronic equipment installed on vibration isolators is consi dered. Account of harmonic vibration, random vibration, shock loads, linear acceleration, acoustic noise is provided. The issues of identification, parametric and structural optimization are considered. Keywords radio engineering device; mechanical characteristics; identification; math modeling; vibration isolator; optimization


Author(s):  
Hans W. Schaeffer ◽  
Atul G. Kelkar

This paper presents a methodology of designing, modeling, and controlling a fully pneumatic semi-active vibration isolator system. The prototype vibration isolator system consists of an air spring, a variable orifice valve, and an accumulator which has the ability to simultaneously adjust the damping and natural frequency characteristics of the system. This paper presents a comprehensive work of modeling, hardware design, control design, and experimental validation of the proposed semi-active vibration isolation system. A higher fidelity model is obtained by complete characterization of nonlinear relationships between pressure versus volume and effective orifice area versus ride height. The performance of three semi-active controller designs — Linear Quadratic Impulse (LQI), Modified Skyhook, and Relative Displacement — is evaluated and compared experimentally using an OEM Peterbilt cabin suspension unit. The results demonstrate that the properly tuned semi-active suspension provides increased vibration isolation over the traditional passive cabin suspension design.


2012 ◽  
Vol 248 ◽  
pp. 475-480
Author(s):  
Guan Jun Zhang ◽  
Xiang Zhu ◽  
Ran Xu ◽  
Tian Yun Li

Recently, the Euler strut is used as the supporting spring in the low frequency isolation. An Euler spring is a column or strut of steel material which is compressed elastically beyond its buckling load, which makes the ratio of the isolated mass to the mass of the supporting spring maximum, and greatly increasing the internal resonant frequencies of the isolator. In this research, the unique mechanical properties and the expressions of the displacement transmissibility of the Euler strut are deduced. The influences of structural parameters of the strut on the stiffness and vibration isolation characteristics are investigated in detail. The results show that the Euler strut has the potential in low frequency vibration isolation, and the length and breadth of the strut can influence the stiffness, transmissibility and critical loading mass respectively.


2005 ◽  
Vol 19 (07n09) ◽  
pp. 1635-1640
Author(s):  
JUAN WANG ◽  
SHAOHUA ZHANG

In this paper, the problem of Electrorheological(ER) technology's application in the vibration isolation system is empirically studied. Based on the particular characteristics of the Electrorheological Fluids (ERF) tunable damping, a metal-spring ER isolator was designed and its working principle is mainly discussed. By theoretical analysis of its simplified physical model, the dynamic response of an ER isolator is frequency- and amplitude- dependent and sensitive to structural parameters. The controllable parameters here can be the system equivalent spring stiffness K and damping coefficient C of ERF. With experiment, the exertion of ER effect was controlled through the change of K and C. Consequently, the system dynamic stiffness, which is used to describe the dynamic properties of system isolation performance, can be changed obviously. According to the dynamic performance tests, the result confirmed that applying different electric field strength could change the dynamic peculiarity of the metal-spring ER isolator. The configuration design of the ER equipment, such as stiffness ratio of two fluid chambers and the size of the electric field, which are important factors for the tunable range of ER isolator.


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