Design and Performance of a MR Torque Transfer Device

Aerospace ◽  
2005 ◽  
Author(s):  
Kevin Molyet ◽  
Constantin Ciocanel ◽  
Hideki Yamamoto ◽  
Nagi Naganathan

Magnetorheological (MR) fluids possess the unique ability to undergo dramatic and nearly completely reversible changes in their rheological properties under the application of a magnetic field. These controllable fluids can serve as quiet, rapid interfaces between electronic controls and mechanical systems. One area of application is to use these fluids in torque transfer devices, such as clutches and brakes. After determining MR fluid properties and behavior using a rheometer, a parallel disk type MR clutch was successfully developed, which utilized a stationary electromagnetic coil. Finite element analysis was used to design the coil and clutch assembly in order to maximize the magnetic field generated within the MR fluid. The resulting magnetic field was uniform over the active portion of the clutch, easily controllable by adjusting the current passing through the coil, and provided a large range of field strength values. The experimentally measured output torque was generally in good agreement with predicted values. This work will detail the design considerations and methodology used to develop this clutch, which can be extended to the design of other MR devices.


2006 ◽  
Vol 129 (4) ◽  
pp. 423-428 ◽  
Author(s):  
John R. Lloyd ◽  
Miquel O. Hayesmichel ◽  
Clark J. Radcliffe

Magnetorheological (MR) fluids change their physical properties when subjected to a magnetic field. As this change occurs, the specific values of the physical properties are a function of the fluid’s time-varying organization state. This results in a nonlinear, hysteretic, time-varying fluid property response to direct magnetic field excitation. Permeability, resistivity and permittivity changes of MR fluid were investigated and their suitability to indicate the organizational state of the fluid, and thus other transport properties, was determined. High sensitivity of permittivity and resistivity to particle organization and applied field was studied experimentally. The measurable effect of these material properties can be used to implement an MR fluid state sensor.



2006 ◽  
Vol 128 (5) ◽  
pp. 604-610 ◽  
Author(s):  
Barkan Kavlicoglu ◽  
Faramarz Gordaninejad ◽  
Cahit Evrensel ◽  
Alan Fuchs ◽  
George Korol

The design, development, and performance characterization of a magnetorheological (MR) fluid clutch for automotive limited slip differential (LSD) applications is presented in this study. The controllability of MR fluids provides an adjustable torque transmission and slippage for the LSD application. Three-dimensional electromagnetic finite element analysis (FEA) is performed to optimize the magnetic circuit and clutch design. Based on the results obtained from the FEA, the theoretical torque transfer capacity of the clutch is predicted utilizing Bingham-Plastic constitutive model. The clutch is characterized at different velocities and electromagnet electric input currents. Both the torque transfer capacity and the response time of the clutch were examined. It was demonstrated that the proposed MR fluid LSD clutch is capable of transferring controllable high torques with a fast response time.



2007 ◽  
Vol 546-549 ◽  
pp. 1673-1676 ◽  
Author(s):  
Wei Jia Meng ◽  
Zhan Wen Huang ◽  
Yan Ju Liu ◽  
Xiao Rong Wu ◽  
Yi Sun

Magnetorheological (MR) fluids are suspensions of micron sized ferromagnetic particles dispersed in varying proportions of a variety of non-ferromagnetic fluids. MR fluids exhibit rapid, reversible and significant changes in their rheological (mechanical) properties while subjected to an external magnetic field. In this paper, a double-plate magneto-rheological fluid (MRF) clutch with controllable torque output have been designed. Electromagnetic finite element analysis is used to optimize the design of the clutch by using the commercial FEA software ANSYS.



2011 ◽  
Vol 239-242 ◽  
pp. 1731-1734 ◽  
Author(s):  
Jian Zuo Ma ◽  
Guo Chao Wang ◽  
Dong Zuo

A magnetorheological (MR) fan clutch is introduced. Based on Herschel-Bulkley model, the equation of transmission torque developed by MR fluids is derived to compute the torque transmission ability in the MR fan clutch. The necessary gap and the need of MR fluid volume between two parallel circular discs of the clutch are carried out. The results indicate that, the transmission torque of the MR fan clutch developed rapidly depend on the yield strength of MR fluid. The necessary gap and the volume for the MR fan clutch can be obtained based on MR fluid properties, the desired control torque ratio, the angular velocity and load torque of the clutch.



2015 ◽  
Vol 1123 ◽  
pp. 35-41
Author(s):  
Burhanuddin Ichwan ◽  
Saiful Amri Mazlan ◽  
Fitrian Imaduddin ◽  
Ubaidillah ◽  
Hairi Zamzuri

Simulation studies on a new concept of modular Magnetorheological (MR) valve using annular-radial gap combination are discussed in this paper. This study predicts and compares the performance of MR valve module with three different commercial kind MR fluids namely the MRF-122EG, MRF-132DG, and MRF140CG. Magnetorheological effect in various types of MR fluid is analyzed using finite element method (FEM) software in term of simulation magnetic field density within the valve module. The approximated functions of permeability and field dependent yield stress for each kind of MR fluid are derived and presented in this paper as a prerequisite for simulation works. The result has shown that the highest pressure drop rating is reached by applying an MR fluid type MRF140CG, for another kind has shown smallest of pressure drop rating because of the ability to produce the achievable pressure drop highly depends on MR fluid properties.



2005 ◽  
Vol 19 (01n03) ◽  
pp. 593-596 ◽  
Author(s):  
J. M. HE ◽  
J. HUANG

Magnetorheological (MR) fluids are materials that respond to an applied magnetic field with a change in their rheological properties. Upon application of a magnetic field, MR fluids have a variable yield strength. Altering the strength of the applied magnetic field will control the yield stress of these fluids. In this paper, the method for measuring the yield stress of MR fluids is proposed. The curves between the yield stress of the MR fluid and the applied magnetic field are obtained from the experiment. The result indicates that with the increase of the applied magnetic field the yield stress of the MR fluids goes up rapidly.



2008 ◽  
Vol 392-394 ◽  
pp. 761-766 ◽  
Author(s):  
G.Q. Wu ◽  
J.L. Zhou ◽  
Xu Dong Zhang ◽  
Y.M. Zhang ◽  
Xiao Ni Chi ◽  
...  

There is a magnetic field inside thrust bearing. The magnetic field distribution is one of the key factors which decide the running state and performance. With the finite element of ANSYS software, the magnetic field of thrust bearing has been analyzed. The rule of changes between the magnetic field and the influencing factors has been discovered. The analysis shows that the direction of exciting current should be opposite other than identical. The greater the ratio of gap length between stator and rotor and working gap length is, the less magnetic field leakage is. The flux leakage of thrust bearing attains 37 percent when the ratio of the gap is 4.0. If the design of a complete machine is not proper, the flux leakage may attain 20 percent upwards through other gaps although that of the bearing itself is almost zero. Calculation of bearing capacity indicates that theoretical value is not exact due to its neglect of magnetic saturation and flux leakage, while FEM value comparably matches the real substance with considering the magnetic saturation and flux leakage. The research provides the theoretical basis for optimization of system structure and selection of current direction control.



Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6541
Author(s):  
Marcin Białek ◽  
Cezary Jędryczka ◽  
Andrzej Milecki

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.



Author(s):  
Wael Elsaady ◽  
S Olutunde Oyadiji ◽  
Adel Nasser

A new magnetorheological (MR) damper has been designed, manufactured, modelled and tested under cyclic loads. A faulty behaviour of the damper was accidentally detected during the experiments. It was deduced that the presence of air bubbles within the MR fluid is the main reason for that failure mode of the damper. The AMT-Smartec+ MR fluid used in the current study, a new MR fluid whose characteristics are not available in the literature, exhibits good magnetic properties. However, the fluid has a very high viscosity in the absence of magnetic field. It is assumed that this high viscosity enables the retention of air bubbles in the damper and causes the faulty behaviour. To prove this assumption, a coupled numerical approach has been developed. The approach incorporates a Finite Element Analysis (FEA) of the magnetic circuit and a Computational Fluid Dynamics (CFD) analysis of the fluid flow. A similar approach was presented in a previous publication in which an ideal behaviour of an MR damper (no effect of air bubbles) was investigated. The model has been modified in the current study to include the effect of air bubbles. The results were found to support the assumptions for the reasons of the failure symptoms of the current MR damper. The results are shown in a comparative way between the former and current studies to show the differences in flow parameters, namely: pressure, velocity and viscosity, in the faultless and faulty modes. The results indicate that the presence of air bubbles in MR dampers reduces the damper force considerably. Therefore, the effect of the high yield stress of MR fluids due to the magnetic field is reduced.



2012 ◽  
Vol 721 ◽  
pp. 114-119 ◽  
Author(s):  
Yuta Enokizono ◽  
Takashi Todaka ◽  
Masato Enokizono

MR (Magnetic Rheological) fluid is a kind of functional fluid, which can be hardened by impressing magnetic flux. MR fluid has the high speed response to the external magnetic field and a big yield stress in comparison with the ferrofluid. In recent years, various devices utilizing MR fluid have been developed. Such developments are enabled with knowledge based on measured viscoelastic properties of MR fluid. However, precise measurement to obtain effect of the magnetic field on viscoelasticity is very difficult. The difficulty exists in generating a uniform magnetic field and evaluating the effective magnetic field. Accurate measurements become possible by solving these problems. In this paper, we propose a new magneto-viscoelasticity measurement system of MR fluid, which can generate a uniform magnetic field.



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