000013177 001__ 13177
000013177 005__ 20161114160330.0
000013177 04107 $$aeng
000013177 046__ $$k2009-06-22
000013177 100__ $$aAglietti G., S.
000013177 24500 $$aImpact oscillator based suspension system for a reaction wheel

000013177 24630 $$n2.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013177 260__ $$bNational Technical University of Athens, 2009
000013177 506__ $$arestricted
000013177 520__ $$2eng$$aThe working of most passive systems for vibration isolation can be reconducted to the dynamics of a single degree of freedom system (mass on a spring and damper) excited by the motion of the support. The damping controls the response at resonance, although the negative effect of viscous damping is to increase the transmissibility at high frequency. An alternative method to control the amplitude of the response of the system at resonance is to include mechanical hard stops that physically limit the amplitude of the oscillation. When the system is excited by a broad band random vibration of the support, if the intensity of the input is relatively low and the mass does not hit the hard stops, the system filters out the high frequency vibrations. However, increasing the amplitude of the input the mass starts to hit the hard stops and mechanical shocks are produced. This type of system, better known as an impact oscillator has been studied by various authors and various mathematical models are available. This paper examines a practical application of this type of system for a reaction wheel to be used on board satellites. Typically in these cases the rotor of the wheel is fixed on a shaft which is rigidly supported by bearings fitted in the supporting structure of the wheel case. The design presented here uses an alternative approach where the rotor/shaft/motor assembly is supported by a soft suspension that when the system is subjected to harsh random vibrations (i.e. the mechanical environment produced by the launch vehicle) allows the suspended mass to clash with the internal walls of the case. A trade off is carried out showing the influence of the various design parameter, e.g. the gap between the oscillating mass and the enclosure, on the loads experienced by the bearings and the motor.

000013177 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013177 653__ $$aReaction Wheel, Impact Oscillator. Abstract. The working of most passive systems for vibration isolation can be reconducted to the dynamics of a single degree of freedom system (mass on a spring and damper) excited by the motion of the support. The damping controls the response at resonance, although the negative effect of viscous damping is to increase the transmissibility at high frequency. An alternative method to control the amplitude of the response of the system at resonance is to include mechanical hard stops that physically limit the amplitude of the oscillation. When the system is excited by a broad band random vibration of the support, if the intensity of the input is relatively low and the mass does not hit the hard stops, the system filters out the high frequency vibrations. However, increasing the amplitude of the input the mass starts to hit the hard stops and mechanical shocks are produced. This type of system, better known as an impact oscillator has been studied by various authors and various mathematical models are available. This paper examines a practical application of this type of system for a reaction wheel to be used on board satellites. Typically in these cases the rotor of the wheel is fixed on a shaft which is rigidly supported by bearings fitted in the supporting structure of the wheel case. The design presented here uses an alternative approach where the rotor/shaft/motor assembly is supported by a soft suspension that when the system is subjected to harsh random vibrations (i.e. the mechanical environment produced by the launch vehicle) allows the suspended mass to clash with the internal walls of the case. A trade off is carried out showing the influence of the various design parameter, e.g. the gap between the oscillating mass and the enclosure, on the loads experienced by the bearings and the motor.

000013177 7112_ $$aCOMPDYN 2009 - 2nd International Thematic Conference$$cIsland of Rhodes (GR)$$d2009-06-22 / 2009-06-24$$gCOMPDYN2009
000013177 720__ $$aAglietti G., S.$$iBianchi, G.$$iBarrington-Brown, J.
000013177 8560_ $$ffischerc@itam.cas.cz
000013177 8564_ $$s237753$$uhttps://invenio.itam.cas.cz/record/13177/files/CD233.pdf$$yOriginal version of the author's contribution as presented on CD, section: Nonlinear dynamics (MS).
000013177 962__ $$r13074
000013177 980__ $$aPAPER