1,721,093 research outputs found
Design, Realization and Analysis of the Performance of a Device for the Energization and Characterization of Magneto-Rheological Fluids
No full textAn innovative multi-gap clutch based on magneto-rheological fluids and electrodynamic effects: magnetic design and experimental characterization
Full text linkIn this paper an innovative multi-gap magnetorheological clutch is described. It is inspired by a
device previously developed by the author’s research group and contains a novel solution based
on electrodynamic effects, capable to considerably improve the transmissible torque during the
engagement phase. Since this (transient) phase is characterized by a non-zero angular speed
between the two clutch shafts, the rotation of a permanent magnets system, used to excite the
fluid, induces eddy currents on some conductive material strategically positioned in the device.
As a consequence, an electromagnetic torque is produced which is added to the torque
transmitted by the magnetorheological fluid only. Once the clutch is completely engaged and the
relative speed between the two shafts is zero, the electrodynamic effects vanish and the device
operates like a conventional magnetorheological clutch. The system is investigated and designed
by means a 3D FEM model and the performance of the device is experimentally validated on a
prototype
A Permanent-Magnets Exciter for Magneto-Rheological Fluid-based Haptic Interfaces
No full textThis paper describes an innovative Haptic Interface device based on Magneto-Rheological Fluid (MRF). A system of permanent magnets and
coils is designed in order to produce a proper distribution of a magnetic field inside the fluid. This distribution, with its spatial
resolution, causes the MRF to assume prescribed shapes and softness profiles that can be directly felt and explored by hand. The device is
designed using a 3-D finite-elements code taking into account the B-H functions of the nonlinear materials (MRF, Permanent Magnets,
ferromagnetic materials). In order to validate the FEM model, some experimental magnetic measurements are taken on a simplified prototype. Furthermore, the
maps of the flux density and those of the shear stress inside the fluid are carefully analyzed. Finally, the interaction between the
operator's hand and the MRF is numerically investigated
Numerical Analysis of an Air-Core Pulsed Alternator taking into account Eddy Currents, Compensating Windings and Excitation/Control Circuits
No full textIn this paper the numerical analysis on an air-core pulsed alternator is presented. The system is investigated by using a dedicated numerical code capable to take into account eddy currents, compensating windings as well as the excitation/control circuits. Furthermore, the possibility to model centrifugal forces and vibrations acting on the shaft due to electric and mechanical unbalances or to misalignments of the shaft from its centered position, make the code a very powerful tool during the design phase of such kind of devices
Analysis of Transmission Lines with Frequency Dependent Parameters by Wavelet -FFT Method
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