• Fire Science and Engineering
• /
• v.26 no.2
• /
• pp.40-52
• /
• 2012

This paper presents the uncertainty analysis results of fire modeling input parameters for motor control center in switchgear room of nuclear power plants. FDS (Fire Dynamics simulator) 5.5 was used to simulate the fire scenario and Latin Hyper Cube Monte Carlo simulations were employed to generate random samples for FDS input parameters. The uncertainty analysis results of input parameters are compared with those of the model uncertainty analysis and sensitivity analysis approaches of NUREG-1934. The study results show that the input parameter uncertainty analysis approach may lead to more conservative results than the uncertainty analysis and sensitivity analysis methods of NUREG-1934.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.2
• /
• pp.54-66
• /
• 1998

In a passenger car automatic transmission, the gear ratio is determined by the combination of clutches and brakes, and each element of th planetary gear set is rotated or held stationary by the action of them. In this study, to investigate the shift characteristics of automatic transmission, the equations of motion are derived from the dynamic model of Ravigneaux type planetary gear set and solved analytically. The shift characteristics of each element of planetary gera set during gear ratio change are investigated by considering the torques and velocities of input, reaction and output elements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.697-701
• /
• 2007

In this paper, noise sources of a planocentric gear reducer are identified by experimental mehod. This study consider a reduction method of a noise/vibration about the gear, axle, bearing and others. Namely, the purpose of this study is to reduce a noise/vibration for a stability of the total system. Form the data to be measured through an experimental method, the problems of the gear, axle, bearing and others are examined closely, and the reducer is derived the model to be the engineering. The mechanism of the problem occurrence is examined through a parametric research about an each influence factor(Load). Lastly, the results of this study propose the model to be improved.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.339-342
• /
• 2008

The gearbox for wind turbine has been increased the size by demanding of bigger power production. The optimal sizing for gearbox is demanded because of limited space on the nacelle. The volume and weight for the gearbox are influenced especially for size of it. Therefore, the purpose of this study investigates the design characteristics using flexible pin of gearbox for minimizing the volume and weight of the gearbox.

• 기계와재료
• /
• v.23 no.3
• /
• pp.182-189
• /
• 2011

전 세계적으로 대체에너지 개발이 활발해지면서 국내에서도 풍력발전에 대한 관심이 높아지고 있다. 풍력발전을 신재생에너지 중에서 가장 상업화에 앞서 있으며 급속한 시장 확대와 산업의 발전을 가져온 분야이다. 1990년대에 개발되어 설치 운용되고 있는 약 20만대의 0.5 MW ~ 3 MW급 중대형 풍력발전기가 세계 여러 곳에서 상업발전을 하고 있으며, 국내에서는 제주도 행원풍력발전단지에 1998년부터 2003년 4월까지 총 15기(약 203억 원 투입)의 풍력 발전기가 도입되어 세워져 있으며, 1998년 8월에 600kW 풍력발전기 1 2호기의 상업운전을 최초로 시작하였다. 최근 풍력발전기의 설치 환경이 육상에서 해상으로 변하면서 5MW급 초대형 풍력발전기의 상용화가 시도되고 있으며 수요 또한 급증하고 있다. 본고에서는 전량 수입에 의존하고 있는 풍력발전기의 핵심 부품인 Yaw system(yaw bearing & drive)의 국내외 시장 동향과 초대형 요 베어링 및 고 강성 유성기어 감속기의 특성을 분석하였으며, 특히 전략적 국산화 개발필요성을 강조하였다.

• Journal of Power System Engineering
• /
• v.21 no.1
• /
• pp.5-10
• /
• 2017

Pitch drive system in wind turbine is composed by the planetary gear system to satisfied its required performance such as long life and light weight for gear train. When the planetary gear system can reduce its volume and weight, the power consumption of the wind turbine can be reduced. In this study, the planetary gear system of the pitch drive system in medium-sized wind turbine is obtained for weight reduction by shape optimization method. And the planetary gear system is verified for their strength by the structural analysis.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.4
• /
• pp.343-351
• /
• 2014

Washing machines designed to clean laundry have been more widely used at home as they reduce household labor and boost the quality of life. Technological advances and better standards of life increase demand for laundry washing performance. Energy efficiency regulations and consumer demand for the larger trend, washing machine makers should be done in performance studies to reduce power, and water consumption and the load on power transmission devices. In this study, performance of a fully automatic washing machine with unconstrained transmission is analyzed through experiment and CFD simulation. It is found that the interaction between laundry and transmission change the washing behavior and affect washing performance with regard to the degree of freedom. The results obtained in this study can be used in developing new washing machine transmissions and make them more robust.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.803-806
• /
• 2002

This paper estimated the stability of centrifuge as its rotating speed compared with the natural frequency of cylinder and screw by finite element analysis. It shows that the one of exciting causes is the tooth passing frequency of input and output parts by the periodic characteristics of transmission error due to an planetary gear having three stages. Also, it proposed the critical speed of cylinder and screw by the Campbell diagram.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.2
• /
• pp.52-59
• /
• 2004

In this paper, the automatic system generation algorithm based on the element combination algorithm discussed in the first part of this paper for designing an arbitrary type of the automatic transmissions is proposed. The powertrain design software using these algorithms is developed. This automotive powertrain design software with user-friendly graphic user interface has two main modules. The first module, the automatic power flow generation module, is already discussed in the previous paper. The second module dealing with the automatic system generation algorithm is discussed in this paper. The power-flow simulation software fur the arbitrary type of powertrain is then developed. The simulation and experimental results of the vehicle equipped with two planetary gear type automatic transmission are compared to validate the proposed algorithms and developed software. The simulation results demonstrate the good agreement with the experimental results.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.814_815
• /
• 2009

본 논문은 로봇관절 구동 및 제어에 활용될 중공모터의 설계 및 특성해석에 대해 연구하였다. 로봇관절에 사용될 중공모터의 경우고 토크출력이 요구될 뿐만 아니라, 저속에서 제어 및 구동 신뢰성이 높은 운전특성이 요구된다. 또한 로봇 관절에 활용하기 위하여 배선처리가 간편한 중공타입의 구조가 요구된다. 따라서 우리는 로봇 구동 및 경량화가 가능하도록 유성기어와 결합이 가능한 외전형 타입의 영구자석 동기전동기의 설계 및 특성해석을 하였다. 먼저 로봇 관절에 적합하도록 FEA 기법을 이용하여 설계하였으며, 실제 시작기 모델을 제작하여 성능실험을 통해 제안된 모터의 특성을 분석하였다.