• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.464-469
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• 2017

This study evaluated the displacements of a Cu bar in the Y-direction and the relationship between swaging pressures and total contact forces to increase the productivity of the rotor core swaging process. Elastic-plastic numerical analyses of four different Cu bar shapes were performed with a constant swaging pressure to evaluate the displacements of the Cu bar in the Y-direction and the contact force distributions at the contact surfaces during the swaging process. Based on the numerical analysis results, the following conclusions were obtained. First, a simplified 2-dimensional cyclic symmetric analysis model was developed for the numerical analysis of the rotor core swaging process. Second, the final displacements of the Cu bar in the Y-direction were nearly the same as the change of the Cu bar size at a constant swaging pressure. Third, a linear relationship between the swaging pressures and the total contact forces, the so called resistance forces, was suggested.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.05a
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• pp.38-38
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• 1999

매설배관은 도로 혹은 철길올 횡단하는 경우와 같이 굴착에 의한 시공이 불가능한 경우에 압업관을 사용하여 시공하며 이러한 압업관은 배관이 토양의 하중으로부터 안 전하게 유지되도록 하는 기능도 한다. 압엽관은 배관과 접촉이 되지 않도록 절연체 를 배관과의 사이에 삽업올 하도록 규정되어 있는데 여러 가지 이유로 배관과 접촉이 되기도 한디 배관과 압업관이 전기적으로 접촉되면 배관을 방식하기 위한 방식전류 를 압입관에 빼앗기게 되고 압업관 내부의 배관은 비방식 상태에 놓이게 되어 부석이 일어날 가능성이 높다. 본 연구는 실제 매설배관 현장에서 배관과 압입관의 접촉여부 에 대하여 조사한 방법 및 결과에 대한 것이다. 본 연구에서는 압업관의 접촉여부를 확인하기 위하여 다음과 같은 방법을 사용하 였다. 첫째. 배관과 압입관의 방식선위를 단순하게 측정하는 것이다. 배관과 압업관 의 전위가 같은가 다른가를 측정하는 방법이다. 둘째, 배관의 방식전류를 on, off하면서 배관과 압입판의 전위거동을 살펴보는 것이다. 셋째, 배관과 압업관을 언위적으로 접촉시켜 흐르는 전류량을 확인함으로써 접촉여부를 확인할 수 있었다. 넷째 배관을 따라 흐르는 방삭전류량을 측정하였다. 이상과 같은 방법을 사용하여 배판과 접촉된 압압관을 확인할 수 있었다. 접촉된 압입관에서 접촉지점을 확인하기 위하여 배관과 압입관 사이에 전류를 인가하고 압입 관의 양단의 배판 사이의 전위 변화를 측정하여 그 전위변화값과 인가한 전류값을 통 하여 계산된 저항올 배관의 길이로 환산하여 대략적인 접촉지점을 확인할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.5
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• pp.653-660
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• 2010

The stern tube bearing is installed to the stern tube and stern boss casting by using the method of the force pressured fitting. The adequate value of the interference between the stern tube bearing and casting should be considered owing to the slip. In this study, to review and compare the fitting force and the contact pressure, the theory of thick walled cylinder is considered to clarify the formula which received from the maker. Also the fitting force and contact pressure are calculated by using the standard value of interference, Young's modulus, Poisson's ratio and friction coefficient.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.10
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• pp.933-940
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• 2013

In this study, we evaluated the heat release performance of two extruded-type and two swaged-type heat sinks used in an inverter for solar power generation. The number of fins and heat transfer areas of the two swaged-type heat sinks, namely S-62 and S-98, are 62 and 98 and $2.8m^2$ and $5.3m^2$, respectively. Those for the two extruded-type heat sinks, namely, E-38 and E-47, are 38 and 47 and $1.8m^2$ and $1.9m^2$, respectively. The heat release fractions of S-62 and S-98 were measured as 82.7 % and 86.3 %, respectively. Those of E-38 and E47 were measured to be 79.6 % and 81.6 %, respectively. In this experiment, despite the mass flow rates of air entering the heat sinks being almost the same, the heat release fractions increased with heat transfer area. Furthermore, despite S-62's heat transfer area being 47.4 % higher than that of E-47, its heat release fraction was higher by only 1.3 %. We believe that this indicates the better heat transfer property of the extruded-type heat sink. S-98's heat release is only 4.4 % higher than that of S-62, but its heat transfer area is 89.3 % higher; this suggests that its heat transfer area need to be optimized.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.3
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• pp.723-734
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• 1991

본 연구에서는 투사체의 충격으로 인해 복합재에 발생하는 손상을 해석하기 위해 우선 이와 관련이 있는 손상에너지를 구할 수 있도록 동적 유한요소 프로그램을 개발하는데 있으며, 이렇게 구한 결과들을 Husman의 실험결과와 비교함으로써 본 논문 의 유한요소 프로그램이 적층복합보에 충격으로 인하여 전달되는 총에너지와 손상에너 지를 구하는데 타당한 것인가를 검토하고 이 프로그램을 이용하여 다음과 같은 것들을 해석하였다.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.185-187
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• 2006

본 논문에서는 평택화력 제2호기 FDF(Forced Draft Fan : 압입송풍기, 이하 FDF) 출구의 공기량제어를 Vane Control 시스템으로 구성되어 있는 것을 구동 유도전동기에 가변속 제어시스템(이하 VFD: Variable Frequency Drive)으로 교체하여 발생한 실험결과를 보여준다. VFD는 Vane을 전개(全開)하고 전동기 속도를 변경시켜 연소에 필요한 노내 공기량을 제어하는 방식이다. VFD 운전은 정속도 Vane 개도 운전에 비해 Throttle Loss를 최소화해서 에너지 절감효과는 크지만 간단한 Vane 제어기에 비해 복잡한 전력전자제어시스템이 어우러진 기기로 신뢰도는 떨어지는 것이 사실이다. 따라서 고도의 신뢰성이 요구되는 전력생산 보일러에서 후비보호책으로 VFD 고장 시에 Vane제어 모드로 절환은 필연적으로 필요한 설비이다. VFD에서 Vane으로 절환 시에 일어나는 과도상태를 최소화하기 위해서는 보일러 연소제어 알고리즘의 최적화가 필요하다. 본 논문에서는 구현된 제어알고리즘을 정리한 것이다.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.463-473
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• 2011

The warm shrink fitting process is generally used to assemble automobile transmission parts (shaft/gear). But the fitting process can cause the dimensions of addendum and dedendum of the gear to change with respect to the fitting interference and the profile of the gear. As a result, there may be additional noise and vibration between gears. To address these problems, we analyzed the warm shrink fitting process according to process parameters; the fitting interference between the outer diameter of the shaft and the inner diameter of the gear, the inner diameter of the gear, addendum and dedendum of the gear, the heating temperature. In this study, a closed form equation for predicting the amount of deformation of addendum and dedendum in the R-direction was proposed. And the FEA method to analyze the cooling process was proposed for thermal-structural-thermal coupled field analysis of the warm shrink fitting process (heating-fitting-cooling process).

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.54-60
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• 2006

Fitting process carried out in automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional changes of gear profile in both radial and circumferential directions. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop optimization technique of warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained by theoretical and finite element analysis and also the expanded amounts of the gear profile in both radial and circumferential directions are within the limit tolerances used in the field.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.37-43
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• 2006

Fitting process carried out in automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional change in both outer diameter and profile of the gear. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop optimization technique of warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained by theoretical and finite element analysis and also the expanded amounts of the outer diameters of the gears have a good agreement with results.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.47-54
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• 2008

Fitting process carried out in the automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by a press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for the automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional changes in both the outer diameter and profile of the gear. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop an optimization technique of the warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field was in good agreements with the results obtained by the theoretical and finite element analysis.