A new high-torque retarder based on combined effects of magnetorheological fluid and eddy current

2018 ◽  
Vol 30 (2) ◽  
pp. 256-271 ◽  
Author(s):  
Hui Huang ◽  
Shumei Chen ◽  
Cheng Wang
Keyword(s):  
Eddy Current ◽  
Material Selection ◽  
Magnetorheological Fluid ◽  
Experimental Result ◽  
Element Analysis ◽  
Operating Concept ◽  
Braking Torque ◽  
High Torque ◽  
The Magnetic Field ◽  
Excitation Circuit

In this article, a new high-torque retarder combining the effects of magnetorheological fluid and eddy current is researched. The new retarder provides a part of the braking torque generated by the shear stress of the magnetorheological fluid and an additional braking torque generated by the effect of the eddy current on the rotors. This operating concept is realized by a common magnetic excitation circuit generated by a new structure with several separated coils. The configurations and design details of the new retarder, including the structure, material selection, and magnetic circuit, are discussed. The mathematical models of braking torque caused by the magnetorheological fluid and eddy current are also derived. Then, a finite element analysis is performed to verify the magnetic field design of the new retarder. Finally, a prototype is fabricated, and the relevant parameters are tested. The experimental result shows that the new retarder provides not only a stable braking torque at low speed but also a great increment of braking torque varied with rotation speed, which effectively improves the total braking torque compared with conventional magnetorheological retarders.

Design of a safety escape device based on magnetorheological fluid and permanent magnet

2012 ◽  
Vol 24 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Bintang Yang ◽  
Tianxiang Chen ◽  
Guang Meng ◽  
Zhiqiang Feng ◽  
Jie Jiang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Dynamic Model ◽  
Magnetic Field Intensity ◽  
Magnetorheological Fluid ◽  
Test Results ◽  
Element Analysis ◽  
Braking Torque ◽  
The Magnetic Field

In this research, a novel safety escape device based on magnetorheological fluid and permanent magnet is designed, manufactured, and tested. The safety escape device with magnetorheological fluid and permanent magnet can provide an increasing braking torque for a falling object by increasing the magnetic field intensity at the magnetorheological fluid. Such increase is realized by mechanically altering the magnetic circuit of the device when the object is falling. As a result, the falling object accelerates first and then decelerates to stop in the end. Finite element analysis is used to determine some of the specifications of the safety escape device for larger braking torque and smaller size. Finite element analysis results are also used for theoretical study and establishment of the dynamic model of the safety escape device. A prototype is realized and tested finally. The experimental test results show that the operation of the prototype conforms to the prediction by the dynamic model and validates the feasible application of magnetorheological fluids in developing falling devices.

Quantitative Research on Cracks in Pipe Based on Magnetic Field Response Method of Eddy Current Testing

2021 ◽  
Vol 36 (1) ◽  
pp. 99-107
Author(s):  
Feng Jiang ◽  
Shulin Liu ◽  
Li Tao
Keyword(s):  
Magnetic Field ◽  
Eddy Current ◽  
Quantitative Research ◽  
Three Dimensional ◽  
Impedance Analysis ◽  
Eddy Current Testing ◽  
Element Analysis ◽  
Defect Parameter ◽  
Current Testing ◽  
The Magnetic Field

The quantitative evaluation of defects in eddy current testing is of great significance. Impedance analysis, as a traditional method, is adopted to determine defects in the conductor, however, it is not able to depict the shape, size and location of defects quantitatively. In order to obtain more obvious characteristic quantities and improve the ability of eddy current testing to detect defects, the study of cracks in metal pipes is carried out by utilizing the analysis method of three-dimensional magnetic field in present paper. The magnetic field components in the space near the crack are calculated numerically by using finite element analysis. The simulation results confirm that the monitoring of the crack change can be achieved by measuring the magnetic field at the arrangement positions. Besides, the quantitative relationships between the shape, length of the crack and the magnetic field components around the metal pipe are obtained. The results show that the axial and radial magnetic induction intensities are affected more significantly by the cross-section area of the crack. Bz demonstrates obvious advantages in analyzing quantitatively crack circumference length. Therefore, the response signal in the three-dimensional direction of the magnetic field gets to intuitively reflect the change of the defect parameter, which proves the effectiveness and practicability of this method.

Influence of Permanent Magnets Installation Approach on the Torque of а Magneto-Rheological Disk Brake

2021 ◽  
Vol 105 ◽  
pp. 184-193
Author(s):  
Ilya Aleksandrovich Frolov ◽  
Andrei Aleksandrovich Vorotnikov ◽  
Semyon Viktorovich Bushuev ◽  
Elena Alekseevna Melnichenko ◽  
Yuri Viktorovich Poduraev
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetorheological Fluid ◽  
Simulation Modelling ◽  
Disc Brake ◽  
Large Area ◽  
Braking Torque ◽  
The Magnetic Field

Magnetorheological braking devices function due to the organization of domain structures between liquid and solid magnetic materials under the action of an electromagnetic or magnetic field. The disc is most widely used as a rotating braking element that made of a solid magnetic material due to the large area of contact with a magnetorheological fluid. Many factors affect the braking characteristics of the magnetorheological disc brake. Specifically, the value of the magnetic field and how the field is distributed across the work element is significantly affected at the braking torque. There are different ways to generate a magnetic field. In this study, the method of installation of permanent magnets into the construction, allowing to increase the braking torque of the magnetorheological disc brake is proposed. Simulation modelling showing the distribution of the magnetic field across the disk depending on the installation of permanent magnets with different pole orientations were carried out. The model takes into account the possibility of increasing the gap between solid magnetic materials of the structure, inside them which the magnetorheological fluid is placed. Comparative estimation of the distribution of the magnetic fields depending on the chosen method of installation of permanent magnets with different orientations of their poles is carried out. Further research is planned to focus on a comparative assessment of the distribution of magnetic fields depending on the selected material of the braking chamber.

scholarly journals Investigation of Thermoplastic Polyurethane Finger Cushion with Magnetorheological Fluid for Soft-Rigid Gripper

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6541
Author(s):  
Marcin Białek ◽  
Cezary Jędryczka ◽  
Andrzej Milecki
Keyword(s):  
Magnetic Field ◽  
3D Printing ◽  
Permanent Magnets ◽  
Force Measurement ◽  
Thermoplastic Polyurethane ◽  
Magnetorheological Fluid ◽  
Fluid Viscosity ◽  
Element Analysis ◽  
Mr Fluid ◽  
The Magnetic Field

This paper presents a study of penetrating a pin into a magnetorheological fluid (MR) cushion focused on the force measurement. The research is supported by detailed finite element analysis (FEA) of the magnetic field distributions in several magnetic field exciters applied to control rheological properties of the MR inside the cushion. The cushion is a part of the finger pad of the jaw soft-rigid gripper and was made of thermoplastic polyurethane (TPU) using 3D printing technology. For the pin-penetrating setup, the use of a holding electromagnet and a magnetic holder were considered and verified by simulation as well as experiment. In further simulation studies, two design solutions using permanent magnets as the source of the magnetic field in the cushion volume to control MR fluid viscosity were considered. The primary aim of the study was to analyze the potential of using an MR fluid in a cushion pad and to investigate the potential for changing its viscosity using different magnetic field sources. The analysis included magnetic field simulations and tests of pin penetration in the cushion as an imitation of object grasping. Thus, an innovative application of 3D printing and TPU to work with MR fluid is proposed.

Development of an Automotive Magnetorheological Brake Via Optimization of Magnetic Circuit

2007 ◽  
Author(s):  
Kerem Karakoc ◽  
Afzal Suleman ◽  
Edward J. Park
Keyword(s):  
Finite Element ◽  
Yield Stress ◽  
Magnetic Circuit ◽  
Design Parameters ◽  
Rotating Disks ◽  
Element Analysis ◽  
Mr Fluid ◽  
Element Simulation ◽  
Braking Torque ◽  
The Magnetic Field

In this paper, the development of a novel electromechanical brake is presented for automotive applications. The proposed brake consists of multiple rotating disks immersed into a magnetorheological (MR) fluid, and an enclosed electromagnet. When current is applied to the electromagnet, the MR fluid solidifies as its yield stress varies as a function of the magnetic field applied by the electromagnet. This controllable yield stress produces shear friction on the rotating disks, generating the braking torque. An electromagnetic finite element analysis was performed to optimize the magnetic circuit within the MR brake and obtain its design parameters. With these parameters, a prototype MR brake was built; and the experimental results were compared to the finite element simulation results.

Design and Analysis of a New Type of Electromagnetic Damper With Increased Energy Density

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Lei Zuo ◽  
Xiaoming Chen ◽  
Samir Nayfeh
Keyword(s):  
Magnetic Field ◽  
Analytical Model ◽  
Eddy Current ◽  
High Efficiency ◽  
High Reliability ◽  
Damping Force ◽  
Element Analysis ◽  
Eddy Current Damper ◽  
New Type ◽  
The Magnetic Field

Eddy current dampers, or electromagnetic dampers, have advantages of no mechanical contact, high reliability, and stability, but require a relatively large volume and mass to attain a given amount of damping. In this paper, we present the design and analysis of a new type of eddy current damper with remarkably high efficiency and compactness. Instead of orienting the magnetic field in a uniform direction, we split the magnetic field into multiple ones with alternating directions so as to reduce the electrical resistance of the eddy current loops and increase the damping force and damping coefficient. In this paper, an analytical model based on the electromagnetic theory for this type of eddy current damper is proposed, and a finite-element analysis (FEA) is carried out to predict the magnetic field and current density. Experimental results agree well with the analytical model and FEA predictions. We demonstrate that the proposed eddy current damper achieves a damping density (N s/m m3) and a dimensionless damping constant as much as 3–5 times as those in the literature. The dependence of damping on velocity and frequency is also examined.

scholarly journals Comparison and Analysis of Magnetic-Geared Permanent Magnet Electrical Machine at No-Load

2014 ◽  
Vol 63 (4) ◽  
pp. 683-692 ◽  
Author(s):  
Xiping Liu ◽  
Dong Chen ◽  
Liang Yi ◽  
Chao Zhang ◽  
Min Wang
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Quantitative Comparison ◽  
Electrical Machine ◽  
Element Analysis ◽  
New Type ◽  
High Torque ◽  
Comparison And Analysis ◽  
Application Fields ◽  
The Magnetic Field

Abstract Magnetic-geared permanent magnet (MGPM) electrical machine is a new type of machine by incorporating magnetic gear into PM electrical machine, and it may be in operation with low-speed, high-torque and direct-driven. In this paper, three types of MGPM machines are present, and a quantitative comparison among them is performed by finite element analysis (FEA). The magnetic field distribution, stable torque and back EMF are obtained at no-load. The results show that three types of MGPM machine are suitable for different application fields respectively according to their own advantages, such as high torque and back EMF, which form an important foundation for MGPM electrical machine research.

Finite Element Analysis of Electromagnetic Device in Magnetorheological Fluid Brake

2012 ◽  
Vol 268-270 ◽  
pp. 1448-1452
Author(s):  
Guang Jie Xiong ◽  
Ling Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Magnetic Fields ◽  
Electromagnetic Fields ◽  
Magnetorheological Fluid ◽  
Air Gap ◽  
Element Analysis ◽  
Braking Performance ◽  
Optimum Parameters ◽  
Braking Torque

Magnetorheological fluid (MRF) Brake is a newly-developed intelligent brake in which traditional mechanical brake friction pairs are replaced by MRF materials and the electromagnetism devices are very important components. The controllable magnetic fields are generated by electromagnetism devices which can make MRF materials create related braking torque to control the braking performance of the MRF Brake. In this paper, the electromagnetism device consists of several coil sets which can generate electromagnetic fields for MRF Brake. By using finite element analysis, the magnetic fields generated by electromagnetism devices are compared analytically under the different conditions, and then the optimum parameters are obtained such as coil arrangements, excitation currents and air gap distances and etc. All these evidences are helpful to design the structure of electromagnetism devices in MRF Brake.

Performance analysis of magnetic gear with Halbach array for high power and high speed

2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong
Keyword(s):  
Permanent Magnet ◽  
Eddy Current ◽  
High Power ◽  
High Speed ◽  
Torque Ripple ◽  
Eddy Current Loss ◽  
Element Analysis ◽  
Current Loss ◽  
Halbach Array ◽  
Magnetic Gear

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.

scholarly journals Failure Analysis on a Collapsed Flat Cover of an Adjustable Ballast Tank Used in Deep-Sea Submersibles

2019 ◽  
Vol 9 (23) ◽  
pp. 5258
Author(s):  
Fang Wang ◽  
Mian Wu ◽  
Genqi Tian ◽  
Zhe Jiang ◽  
Shun Zhang ◽  
...  
Keyword(s):  
Deep Sea ◽  
Material Selection ◽  
High Strength ◽  
External Pressure ◽  
Element Analysis ◽  
Ballast Tank ◽  
Material Inhomogeneity ◽  
Comprehensive Properties ◽  
Ultimate Cause ◽  
Flat Cover

A flat cover of an adjustable ballast tank made of high-strength maraging steel used in deep-sea submersibles collapsed during the loading process of external pressure in the high-pressure chamber. The pressure was high, which was the trigger of the collapse, but still considerably below the design limit of the adjustable ballast tank. The failure may have been caused by material properties that may be defective, the possible stress concentration resulting from design/processing, or inappropriate installation method. The present paper focuses on the visual inspections of the material inhomogeneity, ultimate cause of the collapse of the flat cover in pressure testing, and finite element analysis. Special attention is paid to the toughness characteristics of the material. The present study demonstrates the importance of material selection for engineering components based on the comprehensive properties of the materials.

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