• Tribology and Lubricants
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• 제32권4호
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• pp.107-112
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• 2016

This paper presents a rotordynamic analysis of the reduction gear system applied to the 250 kW super critical CO₂ cycle. The reduction gear system consists of an input shaft, intermediate shaft, and output shaft. Because of the high rotating speed of the input shaft, we install tilting pad bearings, rolloer bearings support the intermediate and output shafts. To predict the tilting pad bearing performance, we calculate the applied loads to the tilting pad bearings by considering the reaction forces from the gear. In the rotordynamic analysis, gear mesh stiffness results in a coupling effect between the lateral and torsional vibrations. The predicted Campbell diagram shows that there is not a critical speed lower than the rated speed of 30,000 rpm of the input shaft. The predicted modes on the critical speeds are the combined bending modes of the intermediate and output shaft, and the lateral vibrations dominate when compared to the torsional vibrations. The damped natural frequency does not strongly depend on the rotating speeds, owing to the relatively low rotating speed of the intermediate and output shaft and constant stiffness of the roller bearing. In addition, the logarithmic decrements of all the modes are positive; therefore all modes are stable.

• 한국정밀공학회지
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• 제29권12호
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• pp.1351-1359
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• 2012

Due to the development of electric and hybrid vehicles, the trend has changed from hydraulic power steering system to electric power steering system (EPS). In this paper, design parameters are deduced through the structural analysis based on the finite element analysis for the intermediate shaft of the EPS on the market. By analyzing the design parameters, the structure design is improved to support the required high torque on the EPS. The numerical analysis is performed to obtain the improved design of the intermediate shaft model and the analysis results are compared with the existing model. It is noted through this numerical approach that the improved design of the intermediate shaft can be acquired the structural safety and high stiffness than existing model.

• 한국생산제조학회지
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• 제9권4호
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• pp.147-153
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• 2000

This paper presents a design method using CAE(Computer Aided Engineering ) with the consideration of reliability for optimal gear driving system. This method considered a configuration of the intermediate shaft. There are four mounting types, such as double straddle, double overhung, output gear overhung, and input ger overhung in the intermediate shaft. The reliability and life analysis are based on the two-parameter Weigbull distribution lives of the gears and bearing . The validity and feasibility of the proposed method are verified by the application to transmission of a industry machine.

• 소성∙가공
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• 제19권2호
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• pp.132-137
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• 2010

In the multi-pass shape drawing process, the appropriate process design is very important to produce sound products. The reduction ratio, die angle, and the intermediate die shape are very important process variable of the multi-pass shape drawing. The aim of this study is the determination of the reduction ratio, die angle, and the intermediate die shape of the 2 pass shape drawing process for producing steering spline shaft. In this study, FE analysis, Taguchi method, and ANN(artificial neural network) were applied to determine the appropriate reduction ratio, die angle, and intermediate die shape. After the determination of the process variables, FE analysis and drawing experiment were performed to evaluate the effectiveness of the determined process variables. The dimensional accuracy of the final drawn spline shaft was evaluated by using 3D surface profiler and 3D laser digitizing system.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.185-191
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• 2002

A window-based multibody dynamics program CADyna(Computer Aided Dynamics) is developed and applied for kinematic and dynamic analysis ova steering system. The program is composed oft pre-processor, a main processor, and a post-processor. The pre-processor is developed with Visual C7+ and the post-processor is developed with OpenGL and TeeChart. The main processor generates the equations of motion employing velocity transformation technique. The developed program is customized for the design of an intermediate shaft in a steering system.

• 한국생산제조학회지
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• 제19권1호
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• pp.33-41
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• 2010

This study was aimed at the design of the dies for the unified pipe joint of the intermediate shaft using the computer simulation to shorten the period of production, on the basis of the process planning which was designed by the field experts. In the computer simulation, 'Deform-3d' and 'eesy-DieOpt' have been used, which are the commercial process analysis and die design program. Through the process analysis, we could know the propriety of the forming process, the inner pressure of the die and the suitable fitting pressure between the insert and the sleeve which was not showing any positive tangential stresses in the insert. Through the simulation of die design, we could know the number of the stress ring, the diameter ratios, the stresses of the die, the shrink fitting tolerance and temperature in the condition of the already determined maximum outer die diameter of the multi-stage former. The validity of the die design using the computer simulation was analyzed by the experiments and the results were satisfactory. As the results of this study, the new and easy die design system for multi-forging has been developed.

• 한국지반공학회논문집
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• 제20권6호
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• pp.29-40
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• 2004

현장타설말뚝의 지지력에 영향을 미치는 요소로는 말뚝의 길이 및 형상, 주면부 거칠기, 지반 및 말뚝의 탄성계수, 지반의 강도, 구속응력 등이 있으나 기존의 국내ㆍ외 설계기준에서는 이들을 모두 고려한 설계방법이 제시되지 않았다. 또한, 지반을 토사와 암반으로만 분류하여 중간특성을 가진 지반(IGM, Intermediate Geomaterials)에 대한 설계기준이 없어서 지지력 예측값이 다양하게 나타났다. 본 연구에서는 현장타설말뚝의 지지력에 관하여 하중전이 시험 결과를 이용해 기존 및 IGM 이론의 적용성을 비교 평가하였다. 연구 결과 기존의 주요 지지력 산정방법들은 실측치와 비교한 결과 지지력을 과소 평가하고 있었으며, IGM 이론의 경우 지지력 예측결과가 실측치와 잘 일치하고 있음을 보였다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권3호
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• pp.185-190
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• 2016

선박이 고출력화, 초대형화 됨에 따라 대형저속 2행정 엔진을 탑재한 선박에서 축계배치의 잘못에 기인하는 주기관 선미측 베어링과, 선미관 후부 베어링의 손상이 증가하는 경향이 있다. 또한 고출력화에 의한 추진축의 강성은 증가한 반면에 선체는 고장력 후판을 사용하므로 이전의 선체보다 훨씬 더 쉽게 변형하는 실정이다. 이는 기존의 선박보다 더욱 정교한 축계배치가 요구됨을 의미한다. 본 연구에서는 열팽창 효과, 감도지수를 이용한 중간축 베어링의 최적위치 선정 및 베어링의 강성을 고려하여, 베어링의 하중 분석 및 영향 계수를 분석함으로서 축계 배치가 이론적으로 최적이 되는 것을 검토하였다. 이를 위하여 축계 배치 계산시 대형 엔진 제조사의 엔진 거치기준을 참조하고, 한국선급 및 DnV 선급의 축계 배치 프로그램을 이용하여 검토하고 그 신뢰성을 검증하였다.

• 대한조선학회논문집
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• 제41권3호
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• pp.35-40
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• 2004

Since the scale of vessels is growing up recently, some troubles between the shaft and after bush bearing are frequently reported. Generally, mean pressure on bush bearing is used as a design criterion. However, in some case of the long bearing such as after bush bearing of the propulsion shaft, it might be liable to be locally under high pressure. As for the main engine bearings and the intermediate shaft bearing, it is reasonable to take the mean pressure as a design criterion. But, in case of after bush bearing, it is not sufficient because of the possibility of high pressure caused by local contact. In this study, Hertzian contact condition was applied to evaluation of the local pressure for after bush bearing. To reduce the local maximum pressure, the height of the after bush bearing was controlled. It was found that local maximum pressure could be reduced effectively by taking a partial slope on the white metal of the aft bush bearing.

• 한국기계기술학회지
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• 제20권6호
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• pp.924-928
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• 2018

The objective of this study is to solve a problem that is occurred during the spline machining of tubular shaft yoke in both side IMS module. In order to simulate the problem, the movement direction of upper die was set as standard case and error case. The material of tubular shaft yoke was set to S20C as refer to the analysis library. The movement directions of upper die were separated with standard case and error case. The error case was set to simulate the problem in the spline machining of tubular shaft yoke. In order to solve the problem, the outer radius of upper die were modelled from 9.40mm to 9.44mm. The simulation results were analyzed and compared in terms of effective stress, metal flow line and folding phenomena characteristics. In case of the outer radius of upper die was 9.42mm, it was observed a relatively uniform effective stress distribution and had a straight metal flow line.