• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.305-310
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• 2012

Planetary gear box is a power transmitter having very high gear ratio in compact volume. The planetary step-down gear box converts high speed and low torque into low speed and high torque, which is widely used in constructional and industrial machinery field. And, the planetary step-up gear box does vice versa working, which is used as main gear box of large sized wind mill system. The large sized planetary gear box must be performed the normal-opposite rotation test as a its durability test for achieving the reliability. The large sized planetary gear box is composed by triple gear trains of sun gear, carrier, and ring gear. If input power is supplied into one of them and the other is fixed, and then another becomes the output part. In this paper, we designed a new test equipment which can do rapid normal and opposite rotational change with only small displacement by supplying test power using the above rotation (driving) characteristics and hydraulic cylinder and link, and also compared and analyzed with existing method through various experiments.

• Journal of the Korean Society of Safety
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• v.13 no.1
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• pp.34-39
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• 1998

This paper describes a evaluation method of sound power radiated from the vibrating faces of a single stage gear box using sound radiation. The vibration caused from meshing gears is transmitted to the gear box faces through shafts and bearings. A Boundary Element Method (BEM) is developed to calculate the sound power radiated from the faces with their velocity response which is based on the Building Block Approach (BBA). Radiation efficiency as well as the sound intensity on the surface of the gear box is also calculated. Sound power of the gear box is larger in the case that bearings have offset to the wall of the gear box than that bearings are on the center of the gear box. The sound power increases with the augmentation of the offset.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.274-279
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• 2009

Reduction Gear Box where from productive site uses the gear with power delivery with high mechanical efficiency of power a deceleration and as the mechanical element union product which has the velocity ratio which is various together is produced with the power occurrence motor and leads gets a high driving force is plentifully used. The above occurs from gear drive issue sound Whine, Noise and Vibration as occurring from the rim process which the gear will bite mainly is delivered with the case etc. gear drive whole which leads the axis and the bearing. The productivity falls with the going straight rate decrease which with like this problem point is caused by with rework the problem point where the cost of production rises under improving boil many kinds analyzed the plan and investigates the resultant acceleration sensor which and a frequency analysis system and was made to apply.

• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.435-440
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• 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 of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.119-125
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• 1999

This article proposes the analytical and experimental approaches for the reduction of vibration generated in the gear box of an NC machine. The lateral critical speed of main spindle and torsional natural frequencies were analyzed and the impact testing of gear box was performed. These results were compared with the forced operating speeds, The vibration was much diminished by redesign of gear module and reinforcement of box structure.

• IE interfaces
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• v.25 no.1
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• pp.134-141
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• 2012

The steering gear box for mid-heavy duty electric vehicles are usually produced by only a few specialized companies. The special techniques, such as designing, producing and testing technology have been veiled. For this reason, steering gear boxes are imported from other country. The durability test with the electric vehicle which is satisfies the design parameters takes several years, and a prototype is installed in the real vehicle for the test. In this research, the steering gear box of the steering system was developed based on the reverse engineering and the testing methods and the steering gear box development process have been suggested. The prototype is also developed with the CAD and CAE tools. Developed steering gear box have been tested in torque tester and have satisfied requied torque. As a result, the process and testing methods studied in this research are useful in the development processes of electric vehicles steering system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.216-221
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• 2000

In this study, two mathematical models are first constructed to analyze vibration characteristics of a gear train - spindle system of an NC lathe gear box. One is a lumped parameter model which is used for calculating natural frequencies of the torsional vibration, the other is a finite element model for analyzing lateral vibration and critical speeds of the spindle system. In addition, this study examines some possible resonance conditions such as gear mesh frequencies, 1X shaft rpm frequencies over whole operating speed range, and so on. The results may be helpful to design a machine tool gear box with low noise and vibration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.785-786
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.94-99
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• 2000

When operating NC lathe, gear box which is equipped with gear train and spindle 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 train-spindle system are first analyzed by using torsional and lateral vibration models of the gear train and shafts. Natural frequencies and modes of the gear box structure are also analyzed by impulse hammer test. Furthermore, measured vibration and noise signals are analyzed and compared with theoretical analysis results. At last it is concluded that the cause of the excessive mise and vibration is the resonance between gear meshing frequency including its side bands, shaft bending and torsional vibration frequencies, and the natural frequencies of th gear box structure. Consequently the noise and vibration levels are greatly reduced by avoiding resonance between them through the redesign of the gear module.