• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.7 s.112
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• pp.697-703
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• 2006

This article proposes a new technique for the reduction of vibration and noise in the geared system by adjusting the distance between gear shafts. The vibration and noise may be produced by the abnormal force applied to the tooth face. And the force may be the cause of ununiform velocity in the driven shaft. If the velocity is obtained to be uniform by adjusting the distance between shafts. the vibration and noise may be reduced to some extent. In order to review, a dynamic analysis model for the gear train used in a mill turret and a test rig are developed. The velocities in the driven shaft are calculated by dynamic simulations for the model and noises in the test rig are measured with varying of the distance between shafts. The comparison of simulation and test data shows that the distance between shafts at the most uniform velocity has the lowest level of noise.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.192-199
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• 2000

The design of multi-stage gear drives is a time-consuming process because it includes more complicated problems, which are not considered in the design of single-stage gear drives. The designer has no determine the number of reduction stages and the gear ratios of each reduction stage. In addition, the design problems include not only dimensional design but also configuration design of gear drive elements. There is no definite rule or principle for these types of design problems. Thus the design practices largely depend on the sense and the experiences of the designer, and consequently result in undesirable design solution. A new and generalized design algorithm has been proposed to support the designer at the preliminary phase of the design of multi-stage gear drives. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. The algorithm consists of four steps. In the first step, the user determines the number of reduction stages. In the second step, gear ratios of every stage are chosen using the random search method. The values of the basic design parameters of a gear are chose in the third step by using the generate and test method. Then the values of the dimensions, such as pitch diameter, outer diameter and face width, are calculated for the configuration design in the next step. The strength and durability of each gear is guaranteed by the bending strength and the pitting resistance rating practices by using AGMA rating formulas. In the final step, the configuration design is carried out using simulated annealing algorithm. The positions of gears and shafts are determined to minimize the geometrical volume (size) of a gearbox while avoiding interferences between them. These steps are carried out iteratively until a desirable solution is acquired. The proposed design algorithm is applied to the preliminary design of four-stage gear drives in order to validate the availability. The design solution has considerably good results in both aspects of the dimensional and the configuration design.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.6
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• pp.546-552
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• 2011

In this study, noise sources of a reducer which is combined a spiral bevel gear and a planocentric gear are identified by experimental method and the noise was reduced by the structure modification of the reducer. In order to identify the noise sources, noise and vibration signals were measured by microphone and accelerometer and these signals were analyzed with waterfall plot. In addition, the frequency response functions were obtained to prove the noise and vibration sources. It was found that the resonance was generated by the gear mesh frequencies and natural frequency of the reducer. The noise of the reducer could be reduced by structure modification.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.51-56
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• 2011

In this study, noise sources of a reducer which is combined a spiral bevel gear and a planocentric gear are identified by experimental method and the noise was reduced by the structure modification of the reducer. In order to identify the noise sources, noise and vibration signals were measured by microphone and accelerometer and these signals were analyzed with waterfall plot. In addition, the frequency response functions were obtained to prove the noise and vibration sources. It was found that the resonance was generated by the gear mesh frequencies and natural frequency of the reducer. The noise of the reducer could be reduced by structure modification.

• Proceedings of the KAIS Fall Conference
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• 2001.11a
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• pp.99-103
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• 2001

Though the research and the development in the field of machine tool was focused on high precision and high speed machine these days, traditional gear reduction device has been used to increase the cutting force which was transmitted from power source, motor In this study, analysis of 2 step gear reducer used in machining center spindle was carried out by using APM WinMachine which is commercial software for the analysis of machine element and system. For the analysis of this device, first of all, the analysis of power source and the transmitting of it were carried out. Then, machine elements like gear, shaft, bearing, and the forth, was analyzed in the view point of life time, static strength, stiffness, fatigue failure, etc. Consequently, we can estimate them and introduce new idea of the design modification of reduction device by this study.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.38-43
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• 2011

Industrial reducer is in general use to Deck Crane. High-precision and high-efficient reducer is minimized the power-loss and energy-loss of a machine. So it contribute the price reduction and life extension. Reducer is usually using the Planetary gear reducer. Planetary gear reducer is composed the sun gear, planet gear, internal gear and casing. Industrial reducer's wear and breakage have a short-life. To solve this problem, it is using the profile-shifted-gear or tooth modification. This study was carried out the effect of addendum modification coefficient on tooth fillet bending strength to planetary reducer. Tooth fillet bending stress is calculate. And all parameter were expressed the function of addendum modification coefficient. And then stress concentration factor of tooth fillet curve was express the function of addendum modification coefficient using comparison between theory and finite element analysis.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.730-733
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• 2001

A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.552-558
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• 2001

When operating lathe gear box which is equipped with geared transmission, it sometimes generates loud noise and excessive vibrations. In order to identify their causes, in this study, torsional and lateral vibration characteristics including critical speeds of the gear transmission system are firstly analyzed using lumped parameter models. Natural frequencies and mode shapes of the gear box structure are also analyzed by using the modal test. Furthermore, measured vibration and noise signals during operations are analyzed and compared with theoretical analysis results. After all, it is concluded that the primary cause of the excessive noise and vibrations is the resonance between gear meshing frequency including its side bands, the frequencies of shaft bending and torsional vibrations, and the natural frequencies of the gear box structure. Consequently the noise and vibration levels are greatly reduced by avoiding resonance between the natural frequencies and gear meshing frequencies through the rearrangement of the gears on the transmission shaft without any gear ratio change.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1475-1482
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• 2001

Nowadays reduction of gear noise in power transmission is very important, because the noise regulation is severe and demand of customer on noise is increased. To reduce gear noise, it is necessary to understand the noise characteristics of helical gear. In this work, we designed test rig for the study of gear noise and installed in semi-anechoic chamber. By using this rig, sound pressure level is measured under varying rotational speed and torque. The frequency characteristics of helical gear noise on the effect of lead errors and torque are discussed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.55-61
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• 2007

The hypoid gear has advantage for the high reduction ratio and compactness. But, geometry design and strength evaluation of the hypoid gear depend on the machine tool of specific production companies because the geometry design and strength evaluation of the hypoid gear are complex and difficult. This paper proposes the development of the design programs to satisfying the geometry and strength of a hypoid gear through optimization technique using the genetic algorithm. The genetic algorithm is designed to optimize a method for minimizing volume. The existing design of hypoid gear in the forklift truck axle is compared with the results of developed optimum design program.