Characteristics of some magnetic-fluid clutch servomechanisms

Parziale, A. J.; Tilton, P. D.

doi:10.1109/t-aiee.1950.5060134

Cited by 6 publications

(2 citation statements)

References 3 publications

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“…8, 9, and 10 can be compared to data published for similar systems. Parziale and Tilton (12) reported data for iron particles in silicone oil and observed 8 kPa for a volume fraction of 0.2 and flux density of 0.3 T. Assuming that the yield stress has a linear relation to the particle volume fraction over this entire range of concentration, yield stress values of 5-8 kPa can be obtained from the data of Parziale and Tilton (13). These values compare favorably with that (4-5 kPa) of modified carbonyl iron dispersed in water in oil emulsion system.…”

Section: Steady Shear and Yield Stress Behaviormentioning

confidence: 99%

Rheological Properties and Stabilization of Magnetorheological Fluids in a Water-in-Oil Emulsion

Park

Chin

Park

2001

Journal of Colloid and Interface Science

120

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Section: Steady Shear and Yield Stress Behaviormentioning

confidence: 99%

Rheological Properties and Stabilization of Magnetorheological Fluids in a Water-in-Oil Emulsion

Park

Chin

Park

2001

Journal of Colloid and Interface Science

120

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“…The torque transmitted at zero slip by the magnetic clutch has been estimated by different authors [3][4][5] as a simple function of the total flux, dimensions of the clutch disc and a coefficient of kinetic friction which is assumed to be independent of the shearing velocity. The total flux produced in the clutch gap is assessed by placing a search coil on the driven disc and taking static measurements.…”

Section: Introductionmentioning

confidence: 99%

Viscous torque of disc-type magnetic fluid slip clutches

Varadakumari¹,

Muraleedharan²

1984

IEE Proc. A Phys. Sci. Meas. Instrum. Manage. Educ. Rev. UK

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The flux density pattern on the disc face of a magnetic clutch is analysed by conformal mapping of the coil-gap configuration. The suspension rheology of iron/silicone mixtures is used to derive the viscous torque transmitted by the clutch disc rotating in a non-Newtonian medium in a narrow enclosure. Since disc Reynolds numbers are small for normal operating slips of fluid clutches, only Couette-type laminar flow occurs without boundary layer in the clutch gap. This viscous torque cannot be predicted by theories based on the shear failure of dry masses. Experimental measurements on a disc-type clutch using torque, speed and temperature transducers show that the theory based on apparent viscosity of the fluid mixture under various shear rates, magnetic inductions and volume fractions is more pertinent to the fluid magnetic clutch. List of symbols b = modulus of elliptic integral B = flux density, T B o = flux density at centre of clutch gap, T C v = volume fraction C vm = maximum possible value of C v d = thickness of clutch disc, m E(4>, yfb) = elliptic integral of the second kind E, E = complete elliptical integral of the second kind with modulus b and (1 -b), respectively F = elliptic integral of the first kind H = magnetising force, A/m g = inner radius of excitation coil, m h = clearance between disc edge and housing, m K, K' = complete elliptic integral of the first kind with modulus b and (1 -b), respectively K a = coefficient denoting pseudoplastic behaviour / = semiaxial length of excitation coil, m r = radius vector r 0 = radius of clutch disc, m R = reluctance of clutch S = shear rate, s " 1 t = width of clutch gap, m T = torque, N m V o = MMF, ampere turns x =(((-b)(c -l) y\ a = apparent viscosity, Ns/m 2 rj^ = asymptotic viscosity, N s / m 2 VaB = apparent viscosity under magnetic induction, N s / m 2 0 = temperature, °C Hi = relative permeability of iron /z 0 = magnetic constant fi p = relative permeability of fluid mixture Me

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