• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.5
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• pp.537-543
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• 2012

In this study, we experimentally investigate a noise mechanism related to the machining accuracy of the reducer in the driving state. We fabricate a planetary reducer and four types of gears for use in the planetary reducer. We use signal analysis to determine the noise and vibration of the reducer at different motor speeds; the motor speed is increased from 0 rpm to the maximum speed in a stepwise manner. In addition, we obtain the sound level by using a sound level meter. The machining accuracy of gears is evaluated by public organizations, Korea Testing Laboratory (KTL), on the basis of the Japanese Industrial Standard (JIS). We analyze and compare the results with the noise and vibration of the reducer.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.877-880
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• 2009

수문의 개폐는 모터에 의한 회전이 권양기에서 감속 되고 증폭된 회전력이 랙에 의하여 직선 운동으로 바뀌어 회전 방향에 따라 상하로 움직여 열리고 닫히게 된다. 권양기는 상부 모터, 감속기, 메인 감속 장치, 동력 차단장치, 좌측 동력변환장치, 우측 동력 변환장치로 구성된다. 본 논문에서는 핀잭식 권양기의 최적 설계를 위하여 보조기어와 메인기어 트레인의 구조 해석, 진동해석 및 설계와 하중에 버틸 수 있는 상부구조물 몸체의 최적 설계를 통하여 설계변수를 확립한다.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.55-60
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• 2020

As research and development of eco-friendly vehicles are expanding worldwide, additional devices of vehicles are reduced or deleted to increase the mileage, or research is being conducted to reduce weight. Among them, the multi-stage transmission that was applied to the internal combustion engine vehicle was deleted and replaced with a reducer, and the initial driving power is secured by increasing the torque through the control of the motor output value. However, since frequent motor speed change can result in a load increase, this study attempts to develop a compact and lightweight manual two-stage reducer with a general reducer structure. Therefore, a two-speed transmission with two gear ratio was designed by inserting a large gear and a small gear in a structure with a parallel shaft to connect the gears with a V-belt in the form of a parallel shaft reducer, and setting the gear ratio of the low and high gears respectively. In addition, power performance according to the rotational speed and load of the transmission was checked through a test, and the heat generation characteristics generated during driving were checked to verify the validity of the transmission.

• Cement Symposium
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• no.24
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• pp.186-192
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• 1996

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2061-2066
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• 2011

A cycloid speed reducer is one of the rotational speed regulation devices of the machinery. A cycloid speed reducer has an advantage of transmitting high torque, but is known to be unsuitable for high speed rotation. However, it is almost impossible in an analytical method to find a use limit speed when installing such a speed reducer in a 200ton loading transporter. In this research the cycloid reducer was simulated to get its performance depending on friction energy loss in time domain by using by LS-DYNA. The maximum torque of the cycloid speed reducer is 3.5ton-m, so the comparison of analysis results between a case of 60rpm rotation and a case of 162rpm rotation with such a torque showed the following results. In the case of 60rpm rotation, the maximum stress appearing in the RV gear and the pin gear was 463MPa and 507MPa. Lost power due to friction was 50kW; In the case of 162rpm rotation, the maximum stress appearing in the RV gear and the pin gear was 550MPa and 538MPa. Lost power due to friction was 175kW, which was shown to be almost impossible to use.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.935-941
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• 2010

HANARO is an open-tank-in-pool-type Korean research reactor that generates 30MW of thermal power. It differs from power plant reactor in that the heat generated by HANARO is exhausted into the atmosphere through a secondary cooling tower, thus maintaining the core temperature constant. During every monthly inspection of the cooling tower, large vibrations that exceeded the permissible limit were observed at cooling fan gear reducer No. 4 of the cooling tower. The purpose of this study is to identify the origin of the large vibration and to repair it. FFT spectrum analysis is performed to identify the part that caused the large vibration. The results of the frequency analysis showed that the vibration frequency was 354 Hz, which is twice the natural frequency of the pinion gear. A check of the pinion gear revealed that there was a crack on the surface of the pinion gear. After the gear was replaced, the reducer operated normally.

• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.142-148
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• 2022

In this paper, the weight reduction design of the yaw gearbox for wind turbine was performed through the finite element analysis method, and the stability was checked by performing the critical speed analysis. The weight reduction product can improve engine efficiency, save parts materials, and earn economic benefits. The yaw gearbox is lightweighted with the goal of achieving a safety rate of 1.3 or higher for wind turbine as indicated by IEC61400-1. In order to reduce the weight of the carrier, a topology optimization method was performed. The safety factor was verified by performing finite element analysis on the carrier. In addition, the housing and carrier were modeled using the finite element method, and the gear train was modeled using MASTA. For the yaw gearbox, the housing and carrier FE model and the gear train model were connected by the partial structural synthesis method to perform the rotational vibration analysis. Vibration excitation sources are mass unbalance and gear mesh frrequemcy, and as a result of the critical speed analysis, it was found that there was no resonance within the operating speed range.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.545-546
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• 2007

• 기계와재료
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• v.19 no.4 s.74
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• pp.104-116
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• 2008

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.635-640
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• 2001

The small gear reductioner noise is caused by gear accuracy, assembling errors, and gear backlash. This main study is an investigation on noise quality of the small gear reductioner through the change of gear backlash. In this study included Gear design parameters related the small gear reductioner, the knowledge of rattle noise related gear backlash, and the experimentation results of the small reductioner noise through change of gear backlash. At last, this study propose the least method of the small gear reductioner noise that is caused by suitable existence of gear backlash.