Variable Inertia Damper Using a Flywheel Filled by MR Fluid

2019 ◽  
Author(s):  
Taichi Matsuoka
Keyword(s):  
Dynamic Performance ◽  
Vibration Reduction ◽  
Moment Of Inertia ◽  
Ball Screw ◽  
Inertia Effect ◽  
Mr Fluid ◽  
Screw Mechanism ◽  
The Moment ◽  
The Magnetic Field ◽  
Outer Circumference

Abstract To get a variable inertia effect for vibration reduction, a semiactive damper using a flywheel filled by MR fluid was developed. The damper comprises a ball screw mechanism and the flywheel, which is able to change a moment of inertia. MR fluid is filled into the flywheel. Particles are clustered at outer circumference edge inside the wheel when the magnetic field is applied to the wheel edge, so the moment of inertia on the flywheel can be changed artificially. The prototype device was manufactured, and the dynamic performance was investigated. Finally the changeable inertia effect was confirmed experimentally.

scholarly journals Modelling of spacecraft spin period during eclipse

2011 ◽  
Vol 29 (5) ◽  
pp. 875-882 ◽  
Author(s):  
E. Georgescu ◽  
F. Plaschke ◽  
U. Auster ◽  
K.-H. Fornaçon ◽  
H. U. Frey
Keyword(s):  
Magnetic Field ◽  
Heat Dissipation ◽  
Spin Model ◽  
Moment Of Inertia ◽  
Magnetic Field Direction ◽  
Spin Period ◽  
The Earth ◽  
Spacecraft Spin ◽  
The Moment ◽  
The Magnetic Field

Abstract. The majority of scientific satellites investigating the Earth magnetosphere are spin stabilized. The attitude information comes usually from a sun sensor and is missing in the umbra; hence, the accurate experimental determination of vector quantities is not possible during eclipses. The spin period of the spacecraft is generally not constant during these times because the moment of inertia changes due to heat dissipation. The temperature dependence of the moment of inertia for each spacecraft has a specific signature determined by its design and distribution of mass. We developed an "eclipse-spin" model for the spacecraft spin period behaviour using magnetic field vector measurements close to the Earth, where the magnetic field is dominated by the dipole field, and in the magnetospheric lobes, where the magnetic field direction is mostly constant. The modelled spin periods give us extraordinarily good results with accumulated phase deviations over one hour of less than 10 degrees. Using the eclipse spin model satellite experiments depending on correct spin phase information can deliver science data even during eclipses. Two applications for THEMIS B, one in the lobe and the other in the lunar wake, are presented.

14N Quadrupole Relaxation of DMF and DMF-d7 in DMSO at Infinite Dilution

1994 ◽  
Vol 49 (11) ◽  
pp. 1016-1018 ◽  
Author(s):  
Xi-an Mao ◽  
Manfred Holz
Keyword(s):  
Relaxation Time ◽  
Infinite Dilution ◽  
Molecular Motion ◽  
Moment Of Inertia ◽  
Square Root ◽  
Inertia Effect ◽  
Quadrupole Relaxation ◽  
Nuclear Quadrupole ◽  
The Moment ◽  
Nuclear Quadrupole Relaxation

Abstract The 14N quadrupole relaxation time in pure DMF is by 9% longer than in pure DMF-d7, showing the dependence of the reorientational molecular motion on the square root of the moment of inertia. But for traces of DMF and DMF-d7 in DMSO, the 14N quadrupole relaxation time tends to obey the "square-root-of-the-reduced-mass law", as expected from the kinetic theory of dense fluids. The vanishing of the moment-of-inertia effect on the intramolecular nuclear quadrupole relaxation is discussed in terms of molecular translation-rotation coupling.

Perception of the moment of inertia of hand tools

1982 ◽  
Author(s):  
Carol Zahner ◽  
M. Stephen Kaminaka
Keyword(s):  
Moment Of Inertia ◽  
Hand Tools ◽  
The Moment

Research on the identification of the moment of inertia of PMSM for industrial robots

2020 ◽  
Author(s):  
Chuanwen Zhang ◽  
Guangxu Zhou ◽  
Ting Yang ◽  
Ningran Song ◽  
Xinli Wang ◽  
...  
Keyword(s):  
Industrial Robots ◽  
Moment Of Inertia ◽  
The Moment

Precision loss of ball screw mechanism under sliding-rolling mixed motion behavior

2021 ◽  
Vol 28 (5) ◽  
pp. 1357-1376
Author(s):  
Bao-bao Qi ◽  
Qiang Cheng ◽  
Shun-lei Li ◽  
Zhi-feng Liu ◽  
Cong-bin Yang
Keyword(s):  
Ball Screw ◽  
Screw Mechanism ◽  
Motion Behavior

On the nuclear equilibrium deformation and the moment of inertia of the band

1971 ◽  
Vol 34 (4) ◽  
pp. 255-256 ◽  
Author(s):  
S.A. Hjorth ◽  
J. Oppelstrup ◽  
G. Ehrling
Keyword(s):  
Moment Of Inertia ◽  
Equilibrium Deformation ◽  
The Moment

New Theorems for Moments of Inertia

1993 ◽  
Vol 21 (4) ◽  
pp. 355-366 ◽  
Author(s):  
David L. Wallach
Keyword(s):  
Regular Polygon ◽  
Moment Of Inertia ◽  
Regular Polygons ◽  
Centre Of Mass ◽  
Moments Of Inertia ◽  
The Moment

The moment of inertia of a plane lamina about any axis not in this plane can be easily calculated if the moments of inertia about two mutually perpendicular axes in the plane are known. Then one can conclude that the moments of inertia of regular polygons and polyhedra have symmetry about a line or point, respectively, about their centres of mass. Furthermore, the moment of inertia about the apex of a right pyramid with a regular polygon base is dependent only on the angle the axis makes with the altitude. From this last statement, the calculation of the centre of mass moments of inertia of polyhedra becomes very easy.

Dynamic Modeling of the Torsional Vibration of the Slewing Mechanism of a Hydraulic Excavator

2012 ◽  
Vol 253-255 ◽  
pp. 2102-2106 ◽  
Author(s):  
Xu Juan Yang ◽  
Zong Hua Wu ◽  
Zhao Jun Li ◽  
Gan Wei Cai
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Moment Of Inertia ◽  
Hydraulic Excavator ◽  
Planetary Gear Trains ◽  
Vibration Model ◽  
Gear Trains ◽  
The Moment ◽  
Relationship Of

A torsional vibration model of the slewing mechanism of a hydraulic excavator is developed to predict its free vibration characteristics with consideration of many fundamental factors, such as the mesh stiffness of gear pairs, the coupling relationship of a two stage planetary gear trains and the variety of moment of inertia of the input end caused by the motion of work equipment. The natural frequencies are solved using the corresponding eigenvalue problem. Taking the moment of inertia of the input end for example to illustrate the relationship between the natural frequencies of the slewing mechanism and its parameters, based on the simulation results, just the first order frequency varies significantly with the moment of inertia of the input end of the slewing mechanism.

Synergetic control of permanent magnet synchronous motor based on load torque observer

2018 ◽  
Vol 233 (8) ◽  
pp. 980-993 ◽  
Author(s):  
Tao Wang ◽  
Jikun Li ◽  
Yuwen Liu
Keyword(s):  
Control Theory ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Moment Of Inertia ◽  
Load Torque ◽  
Synergetic Control ◽  
The Moment

The control of permanent magnet synchronous motor has become an important research, and many control methods have been developed because of its high efficiency and energy-saving characteristics. This article proposes a new motor control approach based on synergetic approach in control theory (SACT) and sliding-mode control (SMC). Since the load torque of the motor will change, the moment of inertia will increase in the experiment. The load torque is estimated by the sliding-mode observer. The moment of inertia is calculated by the least squares method by adding a forgetting factor. The practical application of synergetic control theory broadens the train of thought to meet the demand of high-performance motor drive further. The simulation and experimental results show that this control scheme in this article can improve the transient response and system robustness of dynamic systems.

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