Durability Testing on Magnetorheological Fluids for Clutch and Brake Applications

Gabriel, Claus; Oetter, G.; Kieburg, Christoffer; Laun, Martin

doi:10.1142/9789814340236_0083

Cited by 4 publications

(9 citation statements)

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“…To prove the developed test bench and the reproducibility of the measured results, a comparison with those obtained on a different, rheometer-sized system with radial, double shear gap geometry (Gabriel et al, 2010) is presented. The influencing quantities were chosen accordingly (speed: 15 r/min, current: 0.7 A, and temperature: 20°C).…”

Section: Resultsmentioning

confidence: 99%

“…The main reason for this challenge in durability is the significantly smaller MR fluid volume used in MR clutches and brakes in conjunction with the higher particle concentrations required for technically relevant torque densities (Gabriel et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…This distinct divergence in the durability of dampers and clutches can also be seen in the field of MR devices; while MR dampers offer a sufficient field lifetime (Carlson et al, 2006), providing durable MR clutches and brakes is a much larger challenge. The main reason for this challenge in durability is the significantly smaller MR fluid volume used in MR clutches and brakes in conjunction with the higher particle concentrations required for technically relevant torque densities (Gabriel et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…For the investigation of the durability of different MR fluid formulations, a rheometer-sized test cell was developed (Gabriel et al, 2010; Laun et al, 2008). The degradation of the base oil, in combination with an increasing pressure and a continuously decreased on-state torque, and in-use-thickening (IUT) (Carlson, 2002) are important effects that were detected in some MR fluid formulation tests (Kieburg et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…The degradation of the base oil, in combination with an increasing pressure and a continuously decreased on-state torque, and in-use-thickening (IUT) (Carlson, 2002) are important effects that were detected in some MR fluid formulation tests (Kieburg et al, 2008). Lifetime dissipated energies (LDEs) (Carlson, 2002) of up to 5 MJ/mL were also achieved with optimized high shear stress MR fluid formulations for clutch and brake applications (Gabriel et al, 2010) using a rheometer-sized test cell.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Large-scale test bench for the durability analysis of magnetorheological fluids

Wiehe

Maas

2012

Journal of Intelligent Material Systems and Structures

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Durability is an essential issue for magnetorheological fluids, particularly in brake and clutch applications. To investigate the lifetime dissipated energy within a technically relevant scale and under consideration of the volume of the magnetorheological fluid and the transmitted torque, a large-scale durability test bench is developed that is based on a test actuator for continuous loads. A key benefit of the test bench is the possibility of varying the influencing quantities, which enables the characterization of the magnetorheological fluid during the durability experiment and allows for applicationoriented load cycle profiles with time-varying influencing quantities. Three seal types were tested, offering sufficient performance. The measured results show a dependency between the lifetime dissipated energy and the power dissipation. In addition, a pressure increase indicates the impeding failure of the magnetorheological fluid, while varying the load cycle profile did not show any observable effects.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Large-scale test bench for the durability analysis of magnetorheological fluids

Wiehe

Maas

2012

Journal of Intelligent Material Systems and Structures

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Dynamic and wear study of an extremely bidisperse magnetorheological fluid

Iglesias¹,

Ruiz-Morón²,

Durán³

et al. 2015

Smart Mater. Struct.

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HIGHLIGHTSFive magnetorheological fluids are tested for MR response, and wear and friction A standard four-ball method is used for wear testingThe bimodal (with a magnetite ferrofluid as base liquid) fluid displays the best MR performance both before and after testing Steel scratches are observed in fluids containing the iron particles in base oil, the effect being more important in absence of anti-wear additiveThe bimodal fluid produces a milder wear, at the price of a larger friction coefficient ABSTRACTIn this work the friction and wear properties of five magnetorheological (MR) fluids with varying compositions are investigated. Considering that many of the proposed applications for these fluids involve lubricated contact between mobile metal-metal or polymer-metal parts, the relationship between MR response and wear behavior appears of fundamental importance. One of the fluids (MR#1) contains only the iron microparticles and the base oil; the second and third ones (MR#2 and MR#3) contain an anti-wear additive as well. The fourth one (MR#4) is a well know commercial MR fluid. Finally, MR#5 is stabilized by dispersing the iron particles in a magnetite ferrofluid. The MR response of the latter fluid is better (higher yield stress and postyield viscosity) than that of the others. More important, it remains (and even improves) after the wear test: the pressure applied in the four-ball apparatus produces a compaction of the magnetite layer around the iron microparticles. Additionally, the friction coefficient is larger, which seems paradoxical in principle, but can be explained by considering the stability of MR#5 in comparison to the other four MRs, which appear to undergo partial phase separation during the test. In fact, electron and optical microscope observations confirm a milder wear effect of MR#5, with almost complete absence of scars from the steel test spheres and homogeneous and shallow 3 grooves on them. Comparatively, MR#2, MR#3 and, particularly, MR#1 produce a much more significant wear.

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Durability test device for MR fluids with permanent magnet and V-shaped groove

Abe

Kikuchi

Noma³

2017

Smart Mater. Struct.

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Magnetorheological fluids (MRFs) are functional fluids whose viscosity changes when magnetic fields are applied. Therefore, these fluids are used in force and torque controllable devices. However, particle sedimentation is one of the drawbacks of conventional MRFs. To solve this problem, Kurimoto Co. Ltd developed a new fluid with sub-micron order Fe particles and a silicone-based solvent known as NanoMRF. The particle distributions of this material are stable over several months. However, its durability has not yet been fully discussed. Therefore, we developed new equipment to test endurance and examined the durability of the magnetorheological effect of the NanoMRF as well as a commercially available MRF. Our results show that the durability of the fluids was affected by the stability of the solvent. In particular, the durability is drastically improved when the solvent is supplemented by the peripheral sealing oil. The oxidation of particles is remarkably varied by the kind of solvent as well as the stability of the oxidation film on the surface of the particles. The energy of the collapse and reproduction of the particles was used not only to generate friction among the particles but also to decompose the solvent molecules.

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Durability Testing on Magnetorheological Fluids for Clutch and Brake Applications

Cited by 4 publications

References 0 publications

Large-scale test bench for the durability analysis of magnetorheological fluids

Large-scale test bench for the durability analysis of magnetorheological fluids

Dynamic and wear study of an extremely bidisperse magnetorheological fluid

Durability test device for MR fluids with permanent magnet and V-shaped groove

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