Research on Rotary Parts Vibration Suppression Based on Coaxiality Measurement and Unbalance Constraint

To suppress the vibration of rotary parts, this paper established an unbalanced vibration response control model of rotary parts based on rotating axis coordinate system. This model considered the stacking transformation of geometric parameter errors and mass parameter errors of single stage rotor. First of all, the centroid transfer model based on the actual rotation axis was established, and the unbalanced excitation force vector of each stage of the rotor was studied. Secondly, the unbalanced excitation force vector of each stage of the rotor is substituted into the model of assembly vibration control based on the double constraints optimization strategy. Finally, the simulation analysis and the vibration experiment of three-stage rotor stacking assembly is carried out. The results show that the vibration of the engine rotor can be effectively suppressed by adjusting the assembly phase of the rotors, and the vibration amplitude of the combined rotor assembled by the double constraint optimization assembly strategy is 22.5% less than the vibration amplitude assembled by the direct assembly strategy. Besides, the coaxiality and the unbalance are reduced by 44.1% and 78.4%, which fully shows the advantages of the double constraint optimization assembly strategy.

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Study on Vibration Reduction of Finishing Lapping Machine for Bearing Race

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.199-200.1496 ◽

2011 ◽

Vol 199-200 ◽

pp. 1496-1500

Author(s):

Jia Man ◽

Lian Hong Zhang ◽

Yong Liang Chen

Keyword(s):

Vibration Amplitude ◽

Vibration Reduction ◽

Experimental Studies ◽

Machining Efficiency ◽

Bearing Race ◽

Excitation Force ◽

Lapping Machine ◽

Light Material ◽

Vibration Performance

It is key to improve the machining efficiency of finishing lapping machine to restrain the vibration that raise with work speed. The vibration amplitude is influenced by the excitation force of unbalanced crank-rocker mechanism and the anti-vibration performance of guide. Following improving schemes as adding counterweight to crank-rocker mechanism, adopting the light material motion components and enhancing the anti-vibration performance of guide are proposed based on theoretical and experimental studies. The improving schemes are verified by the experiment.

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Modeling and Experiment on Active Vibration Control of Hydraulic Excitation System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.187.130 ◽

2012 ◽

Vol 187 ◽

pp. 130-133 ◽

Cited By ~ 1

Author(s):

Hui Xian Zhang ◽

Ling Xia Miao

Keyword(s):

Cross Section ◽

Vibration Amplitude ◽

Method Of Characteristics ◽

Active Vibration Control ◽

Computer Code ◽

Measured Data ◽

Vibration Exciter ◽

Lateral Vibration ◽

Active Vibration ◽

Excitation Force

For studying dynamic characteristics of fluid filled pipe under hydraulic excitation force generated actively by a new developed vibration exciter, at first a computer code based on the method of characteristics (MOC) was developed. Then the excitation force calculated by MOC was applied to the corresponding nodes of finite element of pipe, by using Newmark’s method, the dynamic response at every cross section of pipe was obtained. The numerical simulations show that a simple harmonic motion arises at every cross section of the pipe, and the lateral vibration amplitude of every node along the pipe increases as the rising excitation force. In addition, measured data were compared with numerical simulation, which were basically consistent with each other.

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Strategy for enhancing the active harvesting of piezoelectric energy

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x16672592 ◽

2016 ◽

Vol 28 (8) ◽

pp. 1059-1070 ◽

Cited By ~ 9

Author(s):

Kenji Yoshimizu ◽

Yuta Yamamoto ◽

Kei Asahina ◽

Kanjuro Makihara

Keyword(s):

Vibration Amplitude ◽

Vibration Suppression ◽

Control Strategies ◽

Energy Harvest ◽

Critical Problem ◽

New Methods ◽

Piezoelectric Energy ◽

Experimental Implementation ◽

Excitation Force

This article proposes new methods for enhancing the active harvest of piezoelectric energy using the synchronized switch harvesting on inductor (SSHI) technique. It was experimentally confirmed that the energy harvested by the original synchronized switch harvesting on inductor technique was decreased by the suppression of the vibration amplitude, and this critical problem was solved by developing new control strategies, namely, switch harvesting considering vibration suppression (SCVS) and adaptive SCVS (ASCVS). The SCVS technique was designed to intentionally skip some of the switching actions of the original synchronized switch harvesting on inductor technique, while the ASCVS technique enables more flexible variation of the number of skipped switching actions. The skipping of the switching actions facilitates the recovery of the vibration amplitude produced by the excitation force, and the developed strategies thus maintain the vibration amplitude at the highest possible level, resulting in increased energy harvest. The results of the experimental implementation of the proposed strategies showed that they enabled the harvesting of as much as 10.5 times the energy harvested by the original synchronized switch harvesting on inductor technique. The ASCVS technique particularly enables flexible enhancement of the harvested energy under various vibration conditions.

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The Sun as a Magnetic Star

International Astronomical Union Colloquium ◽

10.1017/s0252921100080775 ◽

1976 ◽

Vol 32 ◽

pp. 457-463

Author(s):

John M. Wilcox ◽

Leif Svalgaard

Keyword(s):

Recent Work ◽

Rotation Axis ◽

Polar Field ◽

Magnetic Star ◽

Rotational Axis ◽

Field Variation ◽

The Sun ◽

Arbitrary Angle ◽

Solar Magnetism ◽

Oblique Rotator

SummaryThe sun as a magnetic star is described on the basis of recent work on solar magnetism. Observations at an arbitrary angle to the rotation axis would show a 22-year polar field variation and a 25-day equatorial sector variation. The sector variation would be similar to an oblique rotator with an angle of 90° between the magnetic and rotational axis.

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Σ =13 tilt grain boundary in silicon bicrystal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175946 ◽

1990 ◽

Vol 48 (4) ◽

pp. 562-563

Author(s):

M.J. Kim ◽

Y.L. Chen ◽

R.W. Carpenter ◽

J.C. Barry ◽

G.H. Schwuttke

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Rotation Axis ◽

Czochralski Method ◽

High Resolution Electron Microscopy ◽

Image Simulation ◽

Simulation Techniques ◽

Resolution Electron ◽

The Common ◽

Tilt Grain Boundary

The structure of grain boundaries (GBs) in metals, semiconductors and ceramics is of considerable interest because of their influence on physical properties. Progress in understanding the structure of grain boundaries at the atomic level has been made by high resolution electron microscopy (HREM) . In the present study, a Σ=13, (510) <001>-tilt grain boundary in silicon was characterized by HREM in conjunction with digital image processing and computer image simulation techniques.The bicrystals were grown from the melt by the Czochralski method, using preoriented seeds. Specimens for TEM observations were cut from the bicrystals perpendicular to the common rotation axis of pure tilt grain boundary, and were mechanically dimpled and then ion-milled to electron transparency. The degree of misorientation between the common <001> axis of the bicrystal was measured by CBED in a Philips EM 400ST/FEG: it was found to be less than 1 mrad. HREM was performed at 200 kV in an ISI-002B and at 400 kv in a JEM-4000EX.

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