• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.27-34
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• 2023

This paper presents the application of a magnetic gear to the electric propulsion system for an aircraft. Since high torque is required in aircraft electric propulsion systems, combining a speed reducer can amplify the torque. However, mechanical gears have issues, such as friction, vibration, and heat generation, which lead to maintenance challenges. In the case of a direct-drive motor that does not use mechanical gears, the size and weight of the motor increase to achieve high torque. This paper proposes the application of a magnetic gear to solve the maintenance issues of mechanical gears and the weight increase problem of direct-drive motors in aircraft electric propulsion systems. In this paper, a magnetic gear suitable for aircraft electric propulsion systems is designed, and it is compared with a direct-drive motor in terms of performance and the feasibility of applying the magnetic gear is verified.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.253-261
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• 2014

In this paper, vibration analysis of power differential gear train for 2.5MW wind turbine system is analyzed. which system is composed of two planetary gear set, one helical gear set and main shaft that connected by flange. Planetary gear set, helical gear set, main shaft are modeled in MASTA program and housing, torque arm, carrier, flange components are modeling by finite element method. Each models are combined by component mode superposition. To analysis of natural vibration characteristic about 2.5MW wind turbine gear train was performed and check about critical speed with wind load, mass unbalance, angle misalignment excitation frequency.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.51-58
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• 2016

MLCC is key parts of many electronic products and mixer is used to make MLCC. Currently, non-contact mixer is increasingly used due to its many merits. In case of large capacity non-contact mixer, function of driving gear is important. In this study, therefore, in order to reduce manufacturing cost through optimal design of driving gear of large capacity non-contact mixer, study on shape optimization of driving gear without excessive design modification was performed. As the results, because safety factors of modification model were decreased about 3.0 ~ 3.5 times compared with those of model with robust design, the possibility for saving manufacturing cost was confirmed.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.355-362
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• 2021

Since coaxial magnetic gears use non-contact power transmission, friction, wear, noise, and heat generated in the power transmission process of existing mechanical gears can be minimized. Currently, research for application to various industries is being actively conducted, but among the characteristics of coaxial magnetic gears, the problem of rapidly decreasing torque density at a high gear ratio was discussed. This paper proposes a direction for multiple gear combination using low gear ratio coaxial magnetic gears with high torque density. In order to confirm the effectiveness of the method, the torque density was compared with a single high gear ratio model, and the combination and design direction of multiple coaxial magnetic gears were shown.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.259-266
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• 2020

Magnetic gears have the same characteristics as mechanical gears, and each rotor does not come in contact, which is advantageous over mechanical gears in friction noise, heat generation, and maintenance. In addition, when the rotor using the coil-winding is applied, it is possible to control the output of the gear as well as to cut off its own drive in the emergency situation and to change its gear ratio. So the application of the magnetic gear is infinite. However, when the coil-winding rotor is used, cogging torque due to the attraction force between the permanent magnet and the iron core appears, which leads to an increase in the torque ripple component causing the rotor vibration. Therefore, in this paper, various shapes of the coil-winding rotor are analyzed to reduce the torque ripple of the rotor, and the optimum shape for reducing the torque ripple of the magnetic gear is presented.

• Journal of Internet of Things and Convergence
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• v.10 no.5
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• pp.65-71
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• 2024

FD FAN (forced draft fan) is a device used to pressurize gas or air and transfer it to a desired location, and a vane damper is used to control the suction flow rate. The vane damper is a flow rate control valve that controls the suction flow rate of air by adjusting the opening and closing angle of the vane for complete combustion inside the ship boiler. Most ships have fans that can automatically or manually adjust the flow rate using a link-type vane damper. However, due to the imbalance of the link that controls the angle of the vane at the initial 0-20 degree angle, the vane is suddenly opened in a short moment, and a large amount of flow is instantly introduced into the boiler, resulting in serious soot generation due to incomplete combustion. This is because there are structural problems in the assembly imbalance due to the complex structure of the link controlling the vane damper, the transmission torque applied to the link shaft is not evenly distributed, and the technical problems that cause the shaft to be destroyed due to the phenomenon of being concentrated on a specific link. In this study, in order to develop a gear type vane damper that replaced the link type, the torque generated was analyzed to minimize the amount of backlash and the quality and productivity according to the assembly type were improved. The strength of the bevel gear was proved, and environmental tests for basic IoT research were evaluated in consideration of the specificity of the ship.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1991.06a
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• pp.70-75
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• 1991

기어는 기계시스템에서 동력전달 및 운동전환을 담당하는 기본 요소로 공작기계, 건설기계, 농업기계 등의 산업기계와 항공기, 자동차, 선박등의 운송분야, 사무용 및 계측기기 등 산업전반에 걸쳐 사용되고 있으며, 최근에는 로보트를 위시한 자동화 장치의 구동 및 동력전달 장치로 사용되고 있다. 최근의 기어시스템은 기계류의 일반적인 경향인 고속, 고부하, 결량화 추세에 따라 고정밀, 소형화되어 가고 있으며 부하한계에 가깝도록 큰 하중에 견딜것이 요구되고 있다. 따라서 기어의 설계 및 제작시, 여유있는 설계가 허용되지 않으며 정밀성을 높이기 위한 설계로, 설계인자의 세분화가 요구되어지고 있다. 국제적으로 통용되고 있는 강도설계 규격에서 면압강도시 표면상태계수(Surface condition factor)를 정의하고 있다. 본 연구에서는 동력순환식 기어 시험장치를 이용하여 표면처리 상태가 다른 3종류(열처리를 하지 않은 기어, 침탄 및 고주파 표면 열처리한 기어)의 스퍼어 기어를 이요하여 회전수별 표면거칠기의 변화 상태를 고찰하고, 변수를 응용하여 물리적 의미를 파아갛고, 윤활해석을 통한 윤활조건과 치면상태와의 상호 관계에 대하여 고찰해 보고자 한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.7-13
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• 2015

In this study, we developed a gear-type vane damper which replaces the link type through a proper gear design by means of a finite element analysis. We analyzed the fluid flow according to the amount of angular displacement. torque and backlash problems were addressed in conjunction with the pinion as a structural improvement of the forced draft fan (FD FAN). Through an environmental test. Also, results nearly identical to those in the test could be drawn when using a numerical method. Finally, we compared the gear driving result with simulation results. objective of the present study is to identify a nonlinear flow rate control method for a gear-type vane damper and to propose a damper shape which offers linear flow rate control. This study is related to the development of a gear-type vane damper of the change-link type in a forced draft fan.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.134-139
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• 2010

In this study, we developed the gear type vane damper replacing the link type through gear design using Finite Element Analysis(FEA). FEA about the pinion and the vane shaft in the boss of gear type damper for quality improvement was accomplished. We analyzed fluid flow according to angular displacement. Catched the problem of the torque and backlash bring to the pinion as structure improvement of the forced draft fan(FD FAN). Finally, we compared the gear driving result with simulation. It is the objective of the present study to identify a nonlinear flow rate control of gear type vane damper and to suggest a damper shape with a linear flow rate control. This study is related to the development of gear type vane damper change link type in forced draft fan.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.880-881
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• 2015

최근 풍력발전의 산업이 성장함에 따라 풍력 발전기의 부속품에 대한 연구도 활발해지고 있다. 이에 본 논문에서는 풍력 발전기의 기계적 증속기의 문제점을 개선한 비접촉식 자기 기어를 제안하고 기어비에 따른 기어의 특성을 분석하였다. 각 모델들의 전체 크기 및 자석 사용량은 동일하게 고정하였으며 기어비에 따른 극수 및 회전수만을 조절하여 도출된 결과값을 바탕으로 풍력발전기용 증속기 설계 시 기어비 결정에 대한 지표를 제시하고자 한다.