• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.435-440
• /
• 2001

In this study, torsional and lateral vibrations of a gear box transmission system were analyzed theoretically using some mathematical models and examined to determine the causes of its excessive vibrations. As the results, it was found there exist possibility of resonance between gear mesh frequencies and lateral vibration mode of the transmission shaft during the third shifting mode operation. In order to avoid this resonance, we proposed changing the arrangement of gears on the transmission shaft. The measured vibration levels of the improved gear box were dramatically reduced. These results may be helpful to design a machine tool gear box with low noise and vibration.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.1
• /
• pp.169-176
• /
• 1998

This paper presents the vibration characteristics of a motorcycle body frame. In order to study the excitation mechanism. for example, of handle vibration, discrete models and finite element model are developed for the calculation of natural frequencies and mode shapes of the driveline and body. which can lead to the resonances. Experiments are also conducted to compare with the analytical results From the various kinds of vibration reduction methods, the technical realizable one is presented to reduce the handle vibration responses at the start of driving.

• 전기의세계
• /
• v.26 no.5
• /
• pp.74-82
• /
• 1977

This study is to present a method for reductin of noise and vibration of home electric motors coupled to the mechanical load causing relatively big amplitude of vibration. The noise and vibration factors have been analysed in the divisions such as the pattern related to the armature reaction, the pattern related to the circulating current by induction and the other patterns those are affected by a dditive magnetic field and have an effect on mechanical constants. From the systematic mutual relations between the patterns and daping effects, it is possible to derive the fundamental measure for reduction of noise and vibration. Vibration measurements and analysis were carried out in accordance with the planned experimentation and thre object model was chosen randomly from the production line in a factory where home electric machines were mass-produced. Based on the above-mentioned fundamental measure, suppression effects on noise and vibration have been analysed according to the number of slots, the amount of rotor skew and the way the stator winding connection was series or parallel.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1990.10a
• /
• pp.71-77
• /
• 1990

This paper describes the experimental analysis of the vibration and noise reduction for the washing machine of the home appliances. For the washing machine, the customers always feel electrical and mechanical noise and vibration. First of all, when the dehydration process is working, the washing machine has nonlinear problems and boundary conditions are varied with time. Therefore these problems are very complicated and difficult to analyze. We verify the sources of the noise and vibration and consider the countermeasure to reduce the noise and vibration level of the washing machine.

• Korean Journal of Computational Design and Engineering
• /
• v.8 no.3
• /
• pp.175-183
• /
• 2003

This paper introduces a Web-based vibration analysis system for rotary-type refrigerator compressors. Concern for vibration reduction in compressors has been growing for many years. What is important in vibration reduction is to easily predict the vibration without using a physical compressor. The dynamic model of the compressor is represented as a multi-body dynamic system. Solving the dynamic model is run on a high-performance server. The interfaces of the system are accessible via Web browsers, such as Netscape or Explorer. Anyone who wants to analyze the vibration of the rotary compressor or share the results data can access the system over the Internet regardless of their OS, platform, or location.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.11a
• /
• pp.623-628
• /
• 2000

This paper deals with an analysis and reduction of escalator vibration by using the response surface model. Optimization of the escalator vibration is performed by minimization of the vibration responses which are measured at steps. The response surface models of the factors are constructed by using the experimental data based on the D optimal design method. The multi-objective optimization is also performed by applying desirability function and overlaid contour plot techniques. The optimal solution, which is obtained for a typical escalator system, is applied to reduce the escalator vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.10a
• /
• pp.779-783
• /
• 2012

The gas compressor is one of the important machine in the petrochemical industry. It is likely to have high vibration problems due to having large reaction source and structural characteristic. In this paper we analyze the cause of high vibration in the reciprocating compressor and present a solution to this problems. By performing this case study, we confirm the effectiveness of vibration reduction through excitation source changes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1997.10a
• /
• pp.70-75
• /
• 1997

Power driving shaft systems with reduction gear are frequently equipped with elastic couplings to protect reduction gears and to relieve the torsional vibration problems. In this study, torsional vibration characteristics for the engine shafting system with elastic couplings are investigated and the calculating program is developed. It is confirmed that torsional vibration can be controled by careful selection of a elastic coupling with suitable characteristics and the suitability of a elastic coupling can only be determined as a result of a complete torsional vibration analysis including engine conditions such as misfring for shafting system.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.1
• /
• pp.80-86
• /
• 2008

In this study. the noise sources were identified and the noise and vibration were reduced for an industrial forklift. To identify the noise sourses, noise signals were measured by a microphone on a driver seat and these signals were analyzed with a waterfall plot. For this purpose, the gear mesh frequencies from the gear box of a reducer were not only investigated but noise/vibration sourses of an electric motor were also examined. Furthermore, the frequency response functions were obtained to confirm the vibration and noise sourses. It was found that severe vibration and noise were generated in the casing and the connecting part of the reducer. The severe vibration and noise could be reduced by a structure modification.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.1
• /
• pp.42-48
• /
• 2011

This paper presents the vibration reduction algorithm at the walking-will recognition sensors on the uneven terrain. Recently, concern about walking assistant aids is increasing according to the increase in population of elder and handicapped person. However, most of walking aids don't have any actuators for its movement. So, general walking aids have weakness for its movement to upward/download direction of slope. To overcome the weakness of the general walking aids, many researches for active type walking aids are being progressed. Especially, vibration analysis and impulse reduction are one of the important elements of the active-type walking aid during moving on the outdoor area because the ground has many kinds of obstacles such as speed dumps, puddles and so on. So, we analyze the influence from vibration by uneven terrain. And then, we propose the impulse reduction algorithm to overcome the vibration. All the processes are verified experimentally in an active-type walking aid.