Measurement of Normal Force in Magnetorheological and Ferrofluid Lubricated Bearings

2011 ◽  
Vol 490 ◽  
pp. 25-32 ◽  
Author(s):  
Józef Salwiński ◽  
Wojciech Horak
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Shear Rate ◽  
Rheological Properties ◽  
Magnetic Fluid ◽  
Preliminary Analysis ◽  
Normal Force ◽  
Magnetorheological Fluid ◽  
Study Results ◽  
Field Action

Preliminary analysis of magnetorheological fluid usability in fluid lubricated bearings has been described in the present study. Results of the study aimed at rheological properties of chosen fluids, which possess magnetic properties (both ferrofluids and magnetorheological fluids) with respect to their application in slide bearings have been presented Preliminary analysis of potential advantages related with the magnetic fluid bearing construction was carried out. Results of measurements of normal force developed within magnetorheological fluid and ferrofluid in result of magnetic field action at various shear rate values have been presented.

THE ANALYSIS OF THE WORKING CONDITIONS OF A THRUST SQUEEZE BEARING WITH A MAGNETORHEOLOGICAL FLUID OPERATING IN THE OSCILLATORY COMPRESSION MODE

Tribologia ◽  
2019 ◽  
Vol 285 (3) ◽  
pp. 45-50
Author(s):  
Wojciech HORAK ◽  
Marcin SZCZĘCH
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Rheological Properties ◽  
Working Conditions ◽  
Axial Force ◽  
Magnetorheological Fluid ◽  
Magnetorheological Fluids ◽  
Operating Characteristics ◽  
Carrier Fluid ◽  
Load Conditions

The operating state of thrust plain bearings is a function of many parameters, both geometric and related to load conditions. Besides the methods of controlling bearings of this type used so far, new possibilities of modelling their operating characteristics by using substances with controlled rheological properties as a lubricant can be pointed out. Magnetorheological fluids create such a possibility. These are suspensions of particles with magnetic properties in a carrier fluid (usually in mineral or synthetic oil). The influence of magnetic field on this type of fluids changes their rheological properties. This process is almost instantaneous and fully reversible. The paper presents the results of investigations of a thrust squeeze bearing lubricated with magnetorheological fluid. The aim of the study was to determine the influence of selected factors on the axial force as a result of the oscillatory squeeze load.

Preparation of Magnetorheological Fluid and Study on Its Rheological Properties

2014 ◽  
Vol 13 (02) ◽  
pp. 1450009 ◽  
Author(s):  
Shreedhar Kolekar
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Rheological Properties ◽  
Magnetorheological Fluid ◽  
Magnetic Flux Density ◽  
Iron Loading ◽  
Iron Particles ◽  
Mr Fluid ◽  
Carrier Fluid ◽  
System Type

The present paper focuses on preparation and process of the magnetorheological (MR) fluid whose carrier fluid is silicone-based oil and its additive is the commercial grease with different concentration of iron particles. General properties of MR fluid are discussed and rheological properties like shear rate, shear stress, viscosity of MR fluid can be found by using cone-and-plate sensor system-type rheometer. The result shows that shear stress as a function of magnetic flux density and viscosity does not strictly scale with iron loading.

scholarly journals Investigation of the Rheological Properties of Zn-Ferrite/Perfluoropolyether Oil-Based Ferrofluids

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2653
Author(s):  
Fang Chen ◽  
Xiaobing Liu ◽  
Zhenggui Li ◽  
Shengnan Yan ◽  
Hao Fu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Shear Rate ◽  
Field Strength ◽  
Rheological Properties ◽  
Temperature Variation ◽  
Magnetic Field Strength ◽  
Theoretical Research ◽  
Precipitation Method ◽  
Zn Ferrite ◽  
Co Precipitation

The rheological properties of ferrofluids are related to various applications, such as sealing and loudspeakers, and have therefore attracted widespread attention. However, the rheological properties and their influence on the mechanisms of perfluoropolyether oil (PFPE oil)-based ferrofluids are complicated and not clear. Here, a series of PFPE oil-based ferrofluids were synthesized via a chemical co-precipitation method, and their rheological properties were revealed, systematically. The results indicate that the prepared Zn-ferrite particles have an average size of 12.1 nm, within a range of 4–18 nm, and that the ferrofluids have excellent dispersion stability. The activity of the ferrofluids changes from Newtonian to non-Newtonian, then to solid-like with increasing w from 10 wt% to 45.5 wt%, owing to their variation in microstructures. The viscosity of the ferrofluids increases with increasing Mw (the molecular weight of base liquid PFPE oil polymer), attributed to the increase in entanglements between PFPE oil molecules. The magnetization temperature variation of Zn-ferrite nanoparticles and viscosity temperature variation of PFPE oil together contribute to the viscosity temperature change in ferrofluids. The viscosity of the ferrofluids basically remains unchanged when shear rate is above 50 s−1, with increasing magnetic field strength; however, it first increases and then levels off when the rate is under 10 s−1, revealing that the shear rate and magnetic field strength together affect viscosity. The viscosity and its alteration in Zn-ferrite/PFPE oil-based ferrofluids could be deduced through our work, which will be greatly significant in basic theoretical research and in various applications.

scholarly journals Analysis of Influence of Temperature on Magnetorheological Fluid and Transmission Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Song Chen ◽  
Jin Huang ◽  
Kailin Jian ◽  
Jun Ding
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Rheological Properties ◽  
Temperature Stability ◽  
Transmission Performance ◽  
Mr Fluid ◽  
Influence Of Temperature ◽  
Study Results ◽  
Influence Of Temperature On ◽  
The Magnetic Field

Magnetorheological (MR) fluid shows different performances under different temperature, which causes so many problems like the reduction of rheological properties of MR fluid under a high temperature condition, the uncontrollability of shear stress, and even failure of transmission; on that basis, the influence of temperature on the performance of MR fluid and the cause of the rise in temperature of MR transmission device are analyzed in this paper; the shearing transmission performance of the MR transmission device under the effect of an external magnetic field and the influence of temperature on the shearing stress and transmission performance are analyzed. The study results indicate that temperature highly influences the viscosity of MR fluid, and the viscosity influences the shear stress of the MR fluid. The viscosity of MR fluid gradually declines when temperature rises from 100°C. Once the temperature exceeds 100°C, the viscosity would increase and the temperature stability would decline. Temperature obviously influences the characteristics of MR transmission, and particularly, highly influences the characteristics of MR transmission once being higher than 100°C. The chaining of the material in the magnetic field is influenced, which causes the reduction of the rheological properties, the uncontrollability of the shear stress, and even the failure of transmission.

Magnetorheological Fluid for Levitation Migration Technology

2010 ◽  
Vol 148-149 ◽  
pp. 826-831
Author(s):  
Xu Lin Hu ◽  
Yang Guang ◽  
Pan Chao Cui
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Circuit Design ◽  
Magnetic Fluid ◽  
Magnetic Force ◽  
Magnetic Circuit ◽  
Magnetorheological Fluid ◽  
Directional Migration ◽  
Dispersed Particles ◽  
The Magnetic Field

The dispersed particles of magnetic fluid form stable chain-like clusters under the magnetic field, and shows “the flowing is controllable and the shape is controllable” effect. Based on this characteristic, using migration magnetic acted on the magnetic fluid, the object directional migration can be realize, then the magnetic fluid form ribbon at the same time, has the similar fluctuation behavior. The magnetic fluid aerosol migration principle, the aerosol magnetic circuit design, the magnetic field strength and the magnetic force were separately discussed in this paper. The magnetic fluid hover height using the MSL micrometer dial has determined and aerosol migration feasibility has confirmed using the experiment.

An experimental study on the effects of temperature and magnetic field strength on the magnetorheological fluid stability and MR effect

Soft Matter ◽  
2015 ◽  
Vol 11 (22) ◽  
pp. 4453-4460 ◽  
Author(s):  
Yahya Rabbani ◽  
Mahshid Ashtiani ◽  
Seyed Hassan Hashemabadi
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Field Strength ◽  
Rheological Properties ◽  
Carbonyl Iron ◽  
Silicone Oil ◽  
Magnetorheological Fluid ◽  
Effects Of Temperature ◽  
The Stability ◽  
Mr Effect

In this study, the stability and rheological properties of a suspension of carbonyl iron microparticles (CIMs) in silicone oil were investigated within a temperature range of 10 to 85 °C.

scholarly journals Quasi-Static Rheological Properties of Lithium-Based Magnetorheological Grease under Large Deformation

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2431
Author(s):  
Huixing Wang ◽  
Guang Zhang ◽  
Jiong Wang
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Shear Rate ◽  
Field Strength ◽  
Shear Strain ◽  
Rheological Properties ◽  
Large Deformation ◽  
Magnetic Field Strength ◽  
Maximum Yield ◽  
Cyclic Shear

This paper investigates the quasi-static rheological properties of lithium-based magnetorheological (MR) grease under large deformation. Three types of lithium-based MR grease comprising different mass ratios of carbonyl iron (CI) particles and lithium-based grease were prepared. The dependence of the magneto-induced stress–strain curves for MR grease on CI particles content, shear rate, and shear deformation under quasi-static monotonic shear conditions were tested and discussed. The results demonstrate that the shear rate dependence of the maximum yield stress is significantly weakened by the magnetic field, and this weakening is further enhanced as the CI particles content of MR grease increases. In addition, to evaluate and characterize the behavior of the cyclic shear–stress curves of MR grease under quasi-static condition, cyclic shear tests under different controlled conditions, i.e., CI particles content, shear rate, shear strain amplitude, and magnetic field strength, were conduct and analyzed. The magneto-induced shear stress of MR grease with higher CI particles content shows a sharp decrease during the transition from loading to unloading. Moreover, the experiment results also show that the damping characteristics of MR grease are highly correlated with CI particles content, shear strain, and magnetic field strength.

Research on Rotary Disc-Type MRF Dampers with Nonhomogeneous Magnetic Fields

2008 ◽  
Vol 392-394 ◽  
pp. 497-503 ◽  
Author(s):  
Zhi Cui ◽  
Di Zheng
Keyword(s):  
Magnetic Field ◽  
Shear Rate ◽  
Magnetic Fields ◽  
Magnetorheological Fluid ◽  
Test Stand ◽  
Steady Shear ◽  
Experimental Results ◽  
Magnetic Resistance ◽  
Damping Torque ◽  
The Impact

In this paper, based on the analysis of the damping torque of rotary disc-type magnetorheological fluid (MRF) damper, a new kind of MRF disc-type damper is proposed. The working disc of the new kind of damper has a wedged shape that results in variable working clearances, and hence a nonhomogeneous magnetic field is produced. The magnetic resistance of the MRF filled in the variable clearance is analyzed and the impact of the produced nonhomogeneous magnetic field on the damping torque of the damper is studied. Experiments are conducted and the damper performance under steady shear rate is evaluated with an author-designed test stand. The experimental results show that under the same exciting current and other conditions the output damping torque produced by the MRF of the new kind of damper is much greater than that of the ordinary dampers with parallel disc surfaces and constant working clearance.

Effects of Magnetic Fluid on Machining Characteristics in Magnetic Field Assisted Polishing Process

2013 ◽  
Vol 797 ◽  
pp. 396-400
Author(s):  
Shao Hui Yin ◽  
Zhi Qiang Xu ◽  
Hong Jie Duan ◽  
Feng Jun Chen
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Magnetic Fluid ◽  
Material Removal ◽  
Magnetorheological Fluid ◽  
Magnetic Fluids ◽  
Magnetic Characteristics ◽  
Polishing Process ◽  
Magnetic Cluster ◽  
Machining Characteristics

Magnetic characteristics of three magnetic polishing fluids such as magnetic fluid (MF), magnetorheological fluid (MRF), and magnetic compound fluid (MCF) under magnetic field are experimentally investigated and analyzed. Their magnetic cluster structures under action of magnet field are observed, and their magnetic cluster models are established. Magnetic flied assisted polishing experiments for tungsten carbide are developed used these three kinds of magnetic fluids, material removal and surface roughness are respectively measured. At last, the machining characteristic of three magnetic fluids are contrasted and discussed according to experimental results.

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