• 한국수소및신에너지학회논문집
• /
• 제21권2호
• /
• pp.111-116
• /
• 2010

In this study, the structural analysis was performed to optimize the membrane humidifier with hollow fiber membrane for polymer electrolyte membrane fuel cell system. The main design factors were considered by evaluating the humidifying performance according to various structural parameters such as packing density and length. The effects of operation conditions of membrane humidifier were also elucidated experimentally. Results imply that there are optimum points for the packing density and length of humidifier. It was also found that among operation conditions, relative humidity of wet exhaust gas and temperature of dry inlet gas have major effects on the humidifying performance.

• 한국자동차공학회논문집
• /
• 제21권6호
• /
• pp.72-80
• /
• 2013

For the proper cooling of in-wheel motor, the cooling channel should have the characteristics which are low pressure drop and adequate cooling oil supply to motor part. In this study, the flow performance of cooling channel for in-wheel motor was evaluated and the shape of the channel was optimized. First, the pressure drop and flow distribution characteristics of the initial channel model were evaluated using numerical analysis. Also, by the result of analysis and design modification, 4 design parameters of the channel were selected. Second, using the Taguchi optimal method, the cooling channel was optimized. In the method, nine models with different levels of the design parameters were generated and the flow characteristics of each models was estimated. Base on the result, the main effect of the design parameters was founded and optimized model was obtained. For the optimized model, the pressure drop and oil flow rate were about 0.196 bar and 0.207 L/min, respectively. The pressure drop decreased by about 0.3 bar and the oil flow rate to the motor part increased by about 0.2 L/min compared to the initial model.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.142-143
• /
• 2007

A 1MW class HTS(High-Temperature Superconducting) synchronous motor has been developed. This motor is aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field coil of the developed motor is cooled by way of Neon thermosiphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes performance test results of our motor, which was conducted at steady state in generator mode and motor mode.

• 한국전자통신학회논문지
• /
• 제5권1호
• /
• pp.37-43
• /
• 2010

본 논문에서는 7자유도 매니퓰레이터를 개발에 있어서 각 관절에 2개 이상의 일반적인 모터를 적용하여 중공형 관절을 구현하고, 전장부가 내장된 소형 구조를 설계하였다. 또한 기존의 산업용 로봇의 한계로 지적받고 있는 작업 반경의 한계 및 위험성을 극복할 수 있는 방안을 제시하고 보다 효율적이며, 안전한 매니퓰레이터의 구현 방법을 제시한다.

• 한국정밀공학회지
• /
• 제26권9호
• /
• pp.31-37
• /
• 2009

• Journal of Electrical Engineering and Technology
• /
• 제13권6호
• /
• pp.2284-2291
• /
• 2018

This paper deals with optimum design of surface mounted permanent magnet synchronous motor (SPMSM) for automotive component. For a compact system structure, it was designed as a motor with a 14-pole 12-slot concentrated winding and hollow shaft. The motor is a thin type structure which stator outer diameter is relatively large compared to its axial length and is designed to have a high magnetic saturation for increasing the torque density. Since the high magnetic saturation in the stator core increases the axial leakage flux, a 3-dimensional (3-D) finite element analysis (FEA) is indispensable for torque analysis. However, optimum designs using 3-D FEA is inefficient in terms of time and cost. Therefore, equivalent 2-D FEA which is able to consider axial leakage flux is applied to the optimization to overcome the disadvantages of 3-D FEA. The structure for cost reduction is proposed and optimum design using equivalent 2-D FEA has been performed.

• 한국생산제조학회지
• /
• 제9권4호
• /
• pp.34-47
• /
• 2000

Since carbon fiber epoxy composite materials have excellent properties for structures due to their high specific strength, high specific modulus, high damping and low thermal expansion, the hollow shafts made of carbon fiber epoxy composites have been widely used for power transmission shafts for motor vehicles , spindles of machine tools, motor base, bearing mount for tool up and manufacturing. The molded composite machine elements are not usually accurate enough for mechanical machine elements, which require turning drilling , cutting and grinding. The experiment are surface grinding wheel GC60 to the carbon fiber epoxy composite specimen with respect to staking angle [0]nT , [45]nT, [90]nT on the CNC grinding machine. In this paper, the surface grinding characteristics of composite plate, which are surveyed experimentally and analytically with respect to the grinding force, surface roughness and wheel loading according to the variable depth of cut, wheel velocity and table feed rate are investigated.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제48권1호
• /
• pp.19-26
• /
• 1999

A moving-coil-type linear motor, designed and fabricated, is consisted of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure and an iron core as a pathway for magnetic flux. The interaction between permanent magmet and armature fie1d, so called "push/pull effect", is to shift the airgap flux density variation due to the magnet alone by a certain amount. Thrust therefore is shift downward or upward. The push/pull effect was presented through the FEM analysis and the static tests. We compared the thrust obtained through the FEM analysis with the static tests. Finally, we present the linearity and correction coefficients of the thrust in consideration of the push/pull effects.l effects.

• 대한기계학회논문집A
• /
• 제36권5호
• /
• pp.579-590
• /
• 2012

도시 철도차량의 윤축은 차량 안전에 있어서 매우 중요하지만, 차량 전체의 중량에서 큰 비중을 차지하는 요소로서 철도차량의 경량화에 있어 필수적인 고려 대상이다. 본 연구에서는 현재 중실축인 한국형 표준전동차의 부수 차축과 동력 차축을 중공축화하여 경량화하고자 하였으며, 객관적인 강도 평가를 위해 EU의 차축 설계 및 강도 평가 기준을 적용하였다. 현재 중실 차축의 강도를 평가하고, 이와 동일한 하중 조건에서 중공화된 차축의 응력 수준을 계산하여 현실적으로 적용 가능한 중공축의 내경크기를 결정하고 경량화율을 추정하였다. 또한, 중실차축 및 중공차축에 대해 유한 요소 해석을 수행하여 계산 결과의 타당성을 검증하였다.

• 대한기계학회논문집A
• /
• 제35권9호
• /
• pp.1015-1020
• /
• 2011

최근, MEMS/NEMS 기술을 이용하여 기능성 나노 구조물을 제작하기 위한 공정기술 중에, 마스터 스템프에 형성된 나노패턴을 웨이퍼 등에 복제할 수 있는 나노임프린트 리소그래피 기술이 활발히 연구되고 있다. 본 연구에서는 기존 멀티헤드방식 나노임프린팅 장비에서 사용되던 전동모터를 대신하여 플렉셔 메커니즘과 결합된 나노스템프를 구동하기 위한 사각 형상의 중공형 압전액추에이터를 설계, 제작하였으며, 제조공정이 다른 각각의 시제품의 변위, 발생력 및 응답특성에 관한 검토를 수행한다. 또한, 압전 액추에이터의 변위제어에 대한 제어수법을 간단히 소개하였으며, 제작한 프로토타입의 PI제어기에 의한 변위 제어결과를 소개한다.