Study on the Effects of Magnetic Field on Magnetorheological Fluid Hydraulic Retarder Braking Torque

2017 ◽  
Author(s):  
Binyu Mei ◽  
Xuexun Guo ◽  
Bo Yang ◽  
Shengguang Xiong ◽  
Gangfeng Tan
Keyword(s):  
Magnetic Field ◽  
Magnetorheological Fluid ◽  
Braking Torque ◽  
Hydraulic Retarder

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.

Modelling of a Magnetorheological Fluid Knee in a Prosthetic Leg

2016 ◽  
Author(s):  
The Nguyen ◽  
Saurabh Bapat ◽  
Xinli Wang
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Theoretical Model ◽  
Theoretical Data ◽  
Magnetorheological Fluid ◽  
Theoretical Modelling ◽  
Gap Size ◽  
Applied Current ◽  
Prosthetic Knee ◽  
Braking Torque

The purpose of the study is to theoretically model a prosthetic knee. A knee similar to magnetorheological fluid (MRF) brake is designed and the study focuses on modelling the MRF knee, predict the torque and compare it with the experimental data. The torque generated by the MRF knee is highly dependent on the gap size, angle, and the applied current. Here, the MRF knee features a non-circular rotor which results in a variable gap size for the MR fluid, between the stator and the rotor. Therefore, the gap size varies with the angle of the knee. When the current is applied and MR knee is subjected to a magnetic field, the yield stress produces the shear friction due to which the braking torque is generated. This derives the braking torque as a function of angle and applied current. A torque equation is derived from the theoretical data to yield the predicted results. In addition to the theoretical modelling and derived torque equations, the torque for the MRF fluid is also calculated experimentally. For the validation of the theoretical model and the derived torque equations, they were compared with the experimental results.

Analysis of the Stress Intensity of Rotor Blade in Hydraulic Retarder

2011 ◽  
Vol 179-180 ◽  
pp. 1453-1458
Author(s):  
Jun Yan
Keyword(s):  
Stress Intensity ◽  
Coordinate Transformation ◽  
Rotor Blade ◽  
Distribution Functions ◽  
Rotor Blades ◽  
Fea Model ◽  
Numeric Simulation ◽  
Braking Torque ◽  
Flow Pressure ◽  
Hydraulic Retarder

Based on CFD numeric simulation for hydraulic retarder under full-filled condition, the pressure distribution functions of the rotor blades surfaces are approached by coordinate transformation and surface fitting. Through the APDL program, loads which involved not only centrifugal force but also flow pressure are loaded on the FEA model according to the approximating pressure functions. The FEA model is solved and the blades strength is analyzed more accurately. Noted moment and speed, that is respectively 4000 N • m and 1343rpm, is determined under the promise of blade strength, and controlling strategy is made that constant braking torque shoud be carried out when speed is higher than noted value .

Simulation and experimentation of a magnetorheological brake with adjustable gap

2016 ◽  
Vol 28 (12) ◽  
pp. 1614-1626 ◽  
Author(s):  
Wan-Li Song ◽  
Dong-Heng Li ◽  
Yan Tao ◽  
Na Wang ◽  
Shi-Chao Xiu
Keyword(s):  
Magnetorheological Fluid ◽  
Structure Design ◽  
Experimental Results ◽  
Wear Property ◽  
Braking Performance ◽  
Braking Torque ◽  
The Difference ◽  
The Impact ◽  
Theoretical Analyses ◽  
Magnetostatic Simulation

The aim of this work is to investigate the effect of the small magnetorheological fluid gap on the braking performance of the magnetorheological brake. In this article, theoretical analyses of the output torque are given first, and then the operating principle and design details of the magnetorheological brake whose magnetorheological fluid gap can be altered are presented and discussed. Next, the magnetic circuit of the proposed magnetorheological brake is conducted and further followed by a magnetostatic simulation of the magnetorheological brakes with different sizes of fluid gap. A prototype of the magnetorheological brake is fabricated and a series of tests are carried out to evaluate the braking performance and torque stability, as well as the verification of the simulation results. Experimental results show that the braking torque increases with the increase in the current, and the difference for the impact of the fluid gap on braking performance is huge under different currents. The rules, which the experimental results show, have an important significance on both the improvement of structure design for magnetorheological brake and the investigation of the wear property under different fluid gaps.

Magnetorheological fluid based on amorphous Fe-Si-B alloy magnetic particles

2021 ◽  
pp. 1045389X2110643
Author(s):  
Chuncheng Yang ◽  
Zhong Liu ◽  
Xiangyu Pei ◽  
Cuiling Jin ◽  
Mengchun Yu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Rheological Property ◽  
Magnetic Particles ◽  
Annealing Treatment ◽  
Magnetorheological Fluid ◽  
The Stability ◽  
The Magnetic Field ◽  
Amorphous Particle ◽  
Better Than

Magnetorheological fluids (MRFs) based on amorphous Fe-Si-B alloy magnetic particles were prepared. The influence of annealing treatment on stability and rheological property of MRFs was investigated. The saturation magnetization ( Ms) of amorphous Fe-Si-B particles after annealing at 550°C is 131.5 emu/g, which is higher than that of amorphous Fe-Si-B particles without annealing. Moreover, the stability of MRF with annealed amorphous Fe-Si-B particles is better than that of MRF without annealed amorphous Fe-Si-B particles. Stearic acid at 3 wt% was added to the MRF2 to enhance the fluid stability to greater than 90%. In addition, the rheological properties demonstrate that the prepared amorphous particle MRF shows relatively strong magnetic responsiveness, especially when the magnetic field strength reaches 365 kA/m. As the magnetic field intensified, the yield stress increased dramatically and followed the Herschel-Bulkley model.

Braking performance of a novel frictional-magnetic compound disc brake for automobiles

2018 ◽  
Vol 233 (10) ◽  
pp. 2443-2454 ◽  
Author(s):  
Yan Yin ◽  
Jiusheng Bao ◽  
Jinge Liu ◽  
Chaoxun Guo ◽  
Tonggang Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temperature Rise ◽  
Friction Material ◽  
Maximum Temperature ◽  
Interface Temperature ◽  
Disc Brake ◽  
Braking Performance ◽  
Maximum Temperature Rise ◽  
Disc Brakes ◽  
Braking Torque

Disc brakes have been applied in various automobiles widely and their braking performance has vitally important effects on the safe operation of automobiles. Although numerous researches have been conducted to find out the influential law and mechanism of working condition parameters like braking pressure, initial braking speed, and interface temperature on braking performance of disc brakes, the influence of magnetic field is seldom taken into consideration. In this paper, based on the novel automotive frictional-magnetic compound disc brake, the influential law of magnetic field on braking performance was investigated deeply. First, braking simulation tests of disc brakes were carried out, and then dynamic variation laws and mechanisms of braking torque and interface temperature were discussed. Furthermore, some parameters including average braking torque, trend coefficient and fluctuation coefficient of braking torque, average temperature, maximum temperature rise, and the time corresponding to the maximum temperature rise were extracted to characterize the braking performance of disc brakes. Finally, the influential law and mechanism of excitation voltage on braking performance were analyzed through braking simulation tests and surface topography analysis of friction material. It is concluded that the performance of frictional-magnetic compound disc brake is prior to common brake. Magnetic field is greatly beneficial for improving the braking performance of frictional-magnetic compound disc brake.

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.

Wear Behavior of Rotary Lip Seal Operating in a Magnetorheological Fluid Under Magnetic Field Conditions

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Peng Zhang ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Wear Behavior ◽  
High Volume ◽  
Magnetorheological Fluid ◽  
Engine Oil ◽  
Wear Properties ◽  
Lip Seal ◽  
Sealing Performance ◽  
Stiffness And Damping

A magnetorheological fluid (MRF) is one of many smart materials that can be changed their rheological properties. The stiffness and damping characteristics of MRF can be changed when a magnetic field is applied. This technology has been successfully employed in various low and high volume applications, such as dampers, clutches, and active bearings, which are already in the market or are approaching production. As a result, the sealing performance of MRF has become increasingly important. In this study, the wear properties of seals with MRFs were evaluated by a rotary-type lip seal wear tester. The test was performed with and without a magnetic field. The leakage time was monitored during the tests in typical engine oil conditions. The results showed that the wear resistance of the seal with MRF was decreased under the magnetic field.

scholarly journals Magnetorheological Fluids Behaviour in Oscillatory Compression Squeeze: Experimental Testing and Analysis

2019 ◽  
Vol 13 (4) ◽  
pp. 221-225
Author(s):  
Wojciech Horak ◽  
Marcin Szczęch ◽  
Bogdan Sapiński
Keyword(s):  
Magnetic Field ◽  
Volume Fraction ◽  
Experimental Testing ◽  
Magnetic Field Gradient ◽  
Particle Volume Fraction ◽  
Excitation Frequency ◽  
Magnetorheological Fluid ◽  
Density Level ◽  
Particle Volume ◽  
The Magnetic Field

Abstract This article deals with experimental testing of magnetorheological fluid (MRF) behaviour in the oscillatory squeeze mode. The authors investigate and analyse the influence of excitation frequency and magnetic field density level on axial force in MRFs that differ in particle volume fraction. The results show that, under certain conditions, the phenomenon of self-sealing can occur as a result of the magnetic field gradient and a vacuum in the working gap of the system.

Sign in / Sign up

Export Citation Format

Share Document