• 대한조선학회논문집
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• 제57권5호
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• pp.254-261
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• 2020

The structural safety of hydraulic winch drum and the gears are estimated by the Finite Element Analysis (FEA) and the winch operation experiment. The mesh convergence test is performed and the applied force is the pressure on the drum converted from the rope tension in working condition. The stress of the drum calculated from the strain values of the winch operation experiment shows the agreement with that from the FEA. Most stress values are under the yield strength except for the small hole made for the wire rope fixation. The life of bearings in the drum is calculated using the life prediction formula with the reaction forces from the operation load. One of the two ball bearings shows the short life for impact condition, yet the real prototype winch system shows more life than the numerical value.

• 열처리공학회지
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• 제28권6호
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• pp.300-309
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• 2015

The aim of the present study was to predict the variations in microstructure and deformation occurring during gas carburizing and quenching processes of a SCM420H planetary gear in a real production environment using the finite element method (FEM). The motivation for the present study came from the fact that previous FEM simulations have a limitation of the application to the real heat treatment process because they were performed with material properties provided by commercial programs and heat transfer coefficients (HTC) measured from laboratory conditions. Therefore, for the present simulation, many experimentally measured material properties were employed; phase transformation kinetics, thermal expansion coefficients, heat capacity, heat conductivity and HTC. Particularly, the HTCs were obtained by converting the cooling curves measured with a STS304 gear without phase transformations using an oil bath with an agitator in a real heat treatment factory. The FEM simulation was successfully conducted using the aforementioned material properties and HTC, and then the predicted results were well verified with experimental data, such as the cooling rate, microstructure, hardness profile and distortion.

• Tribology and Lubricants
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• 제21권5호
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• pp.227-235
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• 2005

This paper presents a tribological study on the failure cases of automatic transmission components in a passenger car. The automatic transmission system is composed of torque converter, clutch, brake, planetary gear, and valve body controlling oil pressure of an automatic transmission fluid. The most largest influence components in an automatic transmission are a torque converter and clutch plate in which are influenced by a wear and torque converting energy loss. The failure case study of an automatic transmission indicates that the tribological design and maintenance technologies should be considered as a key design concept. This means that the failure and power energy loss come from the friction, wear and a oil leakage of an automatic transmission, which is related to the oil seal and O-ring seal failures.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.293-294
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• 2011

본 논문에서는 유성기어를 사용한 직병렬 혼합형 하이브리드 자동차(SPHEV)의 파워트레인 모델링과 하이브리드 자동차의 모드(전기자동차 모드(EV), 엔진 모드, 하이브리드 모드(HEV) 등등)변화에 따른 파워 분배 및 동특성 해석에 대하여 기술한다. 내연기관, 전동기, Energy Storage System(ESS)과 같은 구성요소들의 정격은 에너지 개념과 Electrical Peaking Hybrid(ELPH)를 이용하여 설계하였으며, 동특성 분석을 위하여 전력전자 분야 에서 널리 사용되고 있는 시뮬레이션 툴인 PSIM을 이용하여 모델링 하였다.

• 대한기계학회논문집A
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• 제22권3호
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• pp.654-662
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• 1998

Shift quality of an automatic transmission in a vehicle is mainly affected by transient pressures in the hydraulic system during shifting. In this study, dynamic modelings of the hydraulic system and the power train of an automatic transmission are made systematically by a bond-graph method. The dynamic characteristics of the line pressures and clutch/brake pressures during shiftings are investigated by simulations and verified by experiments. The effects of clutch/brake pressures on the shift torque are also investigated through driving simulation.

• 생물환경조절학회지
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• 제4권2호
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• pp.232-239
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• 1995

This study was carried out to get required torque data needed to design and develop a roll-up ventilation system in a pipe-constructed plastic film green-house. The results obtained from this study are as follows : 1. The required torques of a roll-up ventilation system in greenhouse are the functions of its length. The torques should multiplied by the conversion coefficients (2.0 in ceiling vent, 1.8 in side vent) in case of application. 2. In constructing pipe-constructed plastic film greenhouse, a shaft pipe is the largest essential element in roll - up shaft weight constitution which have an effect on the required torques. Therefore, the pipe should be light using nonferrous materials like aluminum alloy. 3. A planetary reduction ventilator of differential ring gear type is suitable for a roll-up ventilation system, because it can make high efficient reduction just using the first step shift.

• 오토저널
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• 제7권3호
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• pp.11-18
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• 1985

세계경제가 만성적으로 저미한 상태에서, 전세계적으로 자동차 생산도 크게 성장하기를 바랄 수 없는 상황이 계속 되고 있다. 한편, 승용차의 기술면에서는, 배기가스 규제대응기술의 개발이 일 단락되고, 석유사정도 일단은 안정상태를 유지하고 있는 가운데, 자동차 본래의 기능 및 유용성을 높이기위한 기술개발에 힘을 기울여 왔다. 승용차의 구동방식에 대해서도 FF(Front Engine, Front Drive)방식이 세계적인 추세이고, 더욱이 4WD(사윤구동차)의 보급이 주목되고 있다. 또 이지 드라이브(Easy Drive)화에의 움직임도 강하여 AT(Automatic Transmission, 자동변속기)가 부착된 자동차의 비율이 검증하고 있으며, 유체토오크 컨버어터(Fluid Torque Converter)와 유 성치차장치(Planetary gear)식의 변속 장치를 조합한 AT는 전자제어기술에 의한 정확한 제어로 그 완성도가 더욱더 높아지고 있다. 또 종래로부터 새로운 AT로서의 기술동향이 주목되고 있 었든 CVT(무단변속기)도 실용화 기술의 개발이 진척되어 일부 양산화 모델의 발표도 있으며, CVT가 AT중에서 그위치를 크게 차지하게 될 날도 머지않은 것으로 생각된다. 이하 근년 관심이 높아지고 있는 4WD 및 AT를 중심으로 승용차의 구동방식과 그 기구의 동향을 해설하기로 한다.

• International Journal of Automotive Technology
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• 제1권1호
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• pp.42-47
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• 2000

This paper concentrates on the design and construction aspects of a transmission for a mid-class passenger car with internal combustion engine. The transmission, consisting of a Continuously Variable Transmission (CVT) with a Van Doorne V-belt, a planetary gear set and a compact steel flywheel is used to prove the concept of mechanical torque assist. The design goal is to obtain a proof of concept transmission with maximal efficiency, using proven transmission technology. With the developed so called Zero Inertia CVT, the fuel economy of the car is improved by operating the engine at its fuel optimal operating line. To achieve a good vehicle acceleration response, the flywheel assists the powertrain mechanically.

• 한국정밀공학회지
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• 제31권4호
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• pp.343-351
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• 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.

• 전력전자학회논문지
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• 제17권4호
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• pp.359-367
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• 2012

In this paper, the input split type series-parallel hybrid electric vehicle (SPHEV) is established and the interpretation of the dynamic characteristics in four kinds of HEV modes, such as electric vehicle mode, engine mode, hybrid mode, and regeneration mode, is described. For this research, the forward-facing approach simulation method is chosen, which is useful for vehicle dynamic analysis. The rating of each powertrain component is designed based on energy-based concept and electrical peaking hybrid (ELPH) method. Finally, the designed powertrain is evaluated with the developed PSiM simulator and simulation results are shown.