Seals Based on Magnetic Fluids for High Precision Spindles of Machine Tools

Urreta, Harkaitz; Aguirre, Gorka; Kuzhir, Pavel; Lacalle, Luis Norberto López de

doi:10.1007/s12541-018-0060-9

Cited by 51 publications

(30 citation statements)

References 17 publications

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“…In recent years, magnetorheological fluids (MR fluids) as one of the smart materials has been attracting the attention of many scholars [ 33 , 34 ]. Lapping or polishing of the hard and brittle materials such as optical glass can be realized by adding a reasonable concentration of abrasive particles in MR fluids with an MR effect.…”

Section: Methodsmentioning

confidence: 99%

Study on Material Removal Model by Reciprocating Magnetorheological Polishing

Wang¹,

Xiu

Sun

et al. 2021

Micromachines

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In this study, a new reciprocating magnetorheological polishing (RMRP) method for a flat workpiece was proposed. Based on the RMRP principle and Preston equation, the material removal rate (MRR) model of the RMRP as well as its normal polishing pressure model was established. On this basis, the effects of different technological parameters including workpiece rotation speed, eccentric wheel rotation speed and eccentricity on the MRR of the workpiece were investigated. The K9 optical flat glass was polished with the RMRP setup to verify the MRR model. The experimental results showed that the effect of workpiece rotation speed on the MRR was much greater than that of eccentric wheel rotation speed and eccentricity, and the MRR increased from 0.0115 ± 0.0012 to 0.0443 ± 0.0015 μm/min as workpiece rotation speed rose. The optimum surface roughness reduced to Ra 50.8 ± 1.2 from initial Ra 330.3 ± 1.6 nm when the technical parameters of the workpiece rotation speed of 300 rpm, the eccentric wheel rotation speed of 20 rpm and the eccentricity of 0.02 m were applied. The average relative errors between the theoretical and experimental values were 16.77%, 10.59% and 7.38%, respectively, according to the effects of workpiece rotation speed, eccentric wheel rotation speed and eccentricity on MRR.

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Section: Methodsmentioning

confidence: 99%

Study on Material Removal Model by Reciprocating Magnetorheological Polishing

Wang¹,

Xiu

Sun

et al. 2021

Micromachines

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“…Despite other types of nanofluids, ferrofluids can be magnetized due to the existence of magnetic nanoparticles in the mixture. Because of this distinct feature, ferrofluids hydro-thermal behavior can be controlled by an external magnetic field, and therefore, they have widespread applications in various fields such as thermal engineering [2][3][4], microfluidics [5], FHD pumps and automatic cooling devices [6][7][8], flow manipulation [9], medicine [10,11] and other commercial applications such as lubrication [12], sealing [13] and magnetic dampers [14]. In the recent years, ferrofluids have received great attention and extensive research efforts have been devoted in order to develop new strategies for the preparation of magnetic nanofluids with improved thermal and magnetic properties.…”

Section: Introductionmentioning

confidence: 99%

Numerical study of magnetic field effect on the ferrofluid forced convection and entropy generation in a curved pipe

Soltanipour

Gharegöz

Oskooee

2020

J Braz. Soc. Mech. Sci. Eng.

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This paper presents the effect of a magnetic field on the ferrofluid flow pattern, heat transfer and entropy generation in a curved pipe. A non-uniform magnetic field is applied to ferrofluid (water + 2% vol. Fe 3 O 4 nanoparticles) flow and under the constant heat flux boundary condition. Governing equations are solved by the finite volume method and based on the SIMPLE algorithm. The major objective of this work is to illustrate the effects of circumferential angle (0 • ≤ ≤ 180 •) and strengths of a magnetic field 0 ≤ Mn ≤ 3 × 10 6 on the hydro-thermal behavior and entropy production rate. It is found that circumferential angle of the magnetic source plays an important role in hydro-thermal performance of a curved pipe. At low magnetic numbers, the optimal circumferential location of the magnetic source is opt = 180 • which leads to the maximum heat transfer enhancement and hydro-thermal performance and the minimal entropy generation rate. For high magnetic numbers, the optimal operating condition occurs at = 0 • and = 60 • depending on the magnetic number. Second law analysis reveals that the major source of entropy generation comes from heat transfer irreversibility which reduces significantly by applying a magnetic field. In the range of studied parameters, the maximum heat transfer enhancement is about 29% which occurs at = 0 • and Mn = 3 × 10 6. Keywords Curved pipe • Entropy generation • Ferrofluid • Heat transfer enhancement • Magnetic field List of symbols C Specific heat at constant pressure (Jkg −1 K −1) d p Particle diameter (m) Ec Eckert number (−) H Magnetic field intensity (Am −1) I Electric current (A) K Thermal conductivity (Wm −1 K −1) k B Boltzmann constant (1.380648 × 10 −23 J K −1) Ms Saturation magnetization (Am −1) Mn Magnetic number (−) m p Magnetic moment of nanoparticles (Am 2) Nu Nusselt number(−) P Pressure (Pa) Pr Prandtl number (−) q′′ Heat flux (Wm −2) q* Non-dimensional heat flux (−) r Radial coordinate (m) R c Radius of curvature (m) Re Reynolds number (−) S f Volumetric entropy generation rate due to friction (Wm −3 K −1) S gen Total volumetric entropy generation rate (Wm −3 K −1) S T Volumetric entropy generation rate due to heat transfer (Wm −3 K −1) T Temperature (K) u, v, w Velocity components (ms −1) x, y, z Cartesian coordinates (m) Greek symbols α Particle volume fraction (−) μ Dynamic viscosity (Pa s −1) μ B Bohr magneton (9.274 × 10 −24 Am 2) μ o Vacuum permeability (Tm A −1) ξ Langevin parameter (−) ρ Density (kg m −3) ϕ v Viscous dissipation function (s −1

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“…Shape memory alloy actuators are known to have a simple operating mechanism, be quiet, excellent repeatability with little hysteresis, and small aging effect. On the other hand, since the actuator operates on thermal energy, the energy efficiency is low, bandwidth is limiting, and response time is rather slow (Amadori et al, 2018; Kim, 2012; Urreta et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Development of variable preload system for machine tool spindle using giant magnetostrictive material Terfenol-D actuator

Kim

Lee

2020

Journal of Intelligent Material Systems and Structures

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Applying a bearing preload of machine tool spindle produces positive effects, including increased stiffness, rotation noise reduction, increase in shaft precision, position adjustment during operation, and prevention of rolling element resonance and rotating slip, along with a significant extension of the bearing lifespan. A variable preload technique is a method that improves the bearing performance by appropriately varying the preload applied to the bearing according to the spindle rotation speed and machining condition. In this study, a novel variable preload method utilizing a Terfenol-D actuator has greater power and more displacement and force than those of other transducer materials such as piezo elements or nickel alloys. Terfenol-D has greater power and more displacement and more force. A prototype of a spindle for the variable preload system using Terfenol-D was fabricated, and the axial force and displacement of the bearing were measured during a running experiment. In order to assess whether the proposed variable preload device can effectively apply preloading to the bearing, a comparative analysis was conducted between the theoretical and empirically obtained values of the bearing axial direction displacement. Through the comparative analysis, the real applicability of the proposed structure was confirmed.

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Seals Based on Magnetic Fluids for High Precision Spindles of Machine Tools

Cited by 51 publications

References 17 publications

Study on Material Removal Model by Reciprocating Magnetorheological Polishing

Study on Material Removal Model by Reciprocating Magnetorheological Polishing

Numerical study of magnetic field effect on the ferrofluid forced convection and entropy generation in a curved pipe

Development of variable preload system for machine tool spindle using giant magnetostrictive material Terfenol-D actuator

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