• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.277-283
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• 2020

In a concentric magnetic gear, which replaces the teeth of a mechanical gear with a permanent magnet, the polar ratio of the magnet that determines the reduction ratio affects the behavior of the magnetic gear dramatically. This study analyzed the density of transmission torque, the efficiency of torque considering the solid loss, and the torque quality, including the cogging characteristics using finite element analysis. When the pole number on the driving side was changed from two to five, it was confirmed that there was an optimal pole ratio, in which the transmission torque was maximized. Because eddy current generation density is proportional to the magnetic field, the transmission efficiency also shows a similar tendency to the transmission torque density, and the efficiency is more than 95% at a low gear ratio. The cogging characteristics due to the interaction of the permanent magnets with the limited number of poles are inversely proportional to the least common multiple between the number of magnets on the drive side and the number of modulator teeth. A test model was built for the transmission torque evaluation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.87-90
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• 2001

감속의 가장 일반적인 형태는 기어 감속일 것이다. 백래쉬를 허용할 경우 전달효율이 98%까지 얻을 수 있지만 백래쉬를 중일수록 효율은 줄어들고 기어가공의 오차가 출력으로 나타나게 되어 정밀 감속기로 쓰기 위해서는 연삭등을 해야만 하게 된다. 본 논고에서는 최근 개발된 여러 종류의 감속기의 구동원리와 그들의 장단점을 들고 로보트에의 응용성을 고찰 해보고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.4
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• pp.225-234
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• 2003

Turbo compressors need high speed rotating impeller in structure, high rate gearbox and conventional induction motor. This mechanical system increased moment of inertia and mechanical friction loss. Recently turbo compressor has adopted a super high-speed motor and driver and have made its size smaller and mechanical friction loss at minimum. In this paper, variable super high - speed motor controller, compressor controller and MMI controller are implemented with only one DSP (TMS320VC33) chip for a 150HP, 70,000rpm direct drive turbo compressor. It was required hardware and software integration. The result of integration, Controller hardware became simple and all control software are developed same developing tool. The implements turbo compressor meets the requirements.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.885-890
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• 2002

Turbo compressor needs high speed rotation of impeller in structure, high rated gearbox and conventional induction motor. This mechanical system increased the moment of inertia and mechanical friction loss. Resently the study of turbo compressor applied super high speed motor and drive, removing gearbox made its size small and mechanical friction loss minimum. In this study we tried to develope variable super high speed motor controller, compressor controller and MMI controller under one DSP based systems for 1500Hp, 70,000rpm direct drive Turbo compressor. It have to do unitification of each controller"s hardware and software. The result of study is applied to a 150Hp direct turbo compressor and makes it goods.oods.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1057-1067
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• 2010

Vibration and noise analysis as well as strength of gear teeth, gear profile design are considered in order to develop the multi-gear train devices of synchro system for the guns of a warship. A new approach to the critical speed calculation of practical industrial multi-mesh geared system is presented. A transfer matrix model based on Hibner's branch method is developed and the natural properties of the branched rotor system are calculated with using the ${\lambda}$-matrix formulation. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors and the transmitted errors of the gearing are considered, shows that, at theoperating speed, there are not the critical speed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.91-95
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• 1992

현재 대부분의 공작기계에서는 모터의 동력을 주축으로 전달하기 위해서 커플링, 밸트,기어 등을 사용하고 있지 만 주축이 고속회전할 수록 커플링 구동방법에서는 주축과 모터의 미스얼라인먼트에 의한 진동과 소음이 커지고 벨트 구동방법에서는 원심력에 의한 벨트 장력의 증가 및 벨트의 파손현상, 벨트와 풀리간의 미끄럼현상 등이 발생하며, 기거 구동방법에서는 기어간의 금속접촉에 의한 진동과 소음이 증대하게 된다. 본 연구에서는 모터내장형 주축의 동특성을 체계적으로 해석하기 위해서 유한요소모델을 도입하였다. 특히 공작기계 주축은 세장비가 비교적 작기 때문에 Timoshenko보 이론으로 모델화하였고, 여러장의 얇은 철심용 강판들도 적층된 내장형 모터의 회전부(rotor)는 굽힘변형 및 전단변형에 대해서 상당 수준의 강성효과를 나타내기 때문에 질량효과 외에도 그 강성효과를 수학적 모델에서 고려하였다, 또한 진동실험 결과로 부터 모터회전부의 강성특성을 규명하는 방법을 제시하였으며, 제안된 규명방법의 유용성은 모터내장형 주축에 대한 모드매개변수의 이론값과 실험값을 비교함으로써 입증하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.381-382
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• 2014

하이브리드 자동차는 동력을 얻기 위해 엔진과 전동기를 모두 사용한다. 이 하이브리드 자동차의 구동부 구조는 다양한 형태로 구성할 수 있는데, 이 중 직렬-병렬 구조는 엔진의 토크 및 속도 자유도를 모두 확보할 수 있어 높은 효율을 달성할 수 있다. 직렬-병렬 구조는 발전기, 전동기, 그리고 속도 분배를 위한 유성 기어를 이용하여 주로 구현되고 있고, 최근에는 다양한 새로운 형태의 전동기가 개발되어 이를 구동부에 적용하는 것에 관한 연구가 진행되고 있다. 본 논문에서는 이 중 고정자를 회전자에 독립적으로 회전시킬 수 있는 새로운 형태의 전동기를 사용하는 구조에 관한 내용을 다룬다. 위의 전동기는 기존 구조에서 유성 기어 및 발전기의 역할을 대체하여 토크 분배 및 전기적 출력 변환을 수행할 수 있다. 또한, 회전하는 고정자에 인버터 회로를 탑재하여 슬립 링 대신 회전하는 고정자에 전력을 공급하는 방식을 제안한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2001.07a
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• pp.103-108
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• 2001

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1327-1334
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• 2012

This study shows the conformance-based design results of a fourth-order dynamic actuator showing a performance variation caused by variation in the components as well as aero-induced disturbances. The actuator comprises a BLDC motor, spur gear and worm gear assembly, and canard. The actuator performance was evaluated by using time-variant angle information of the canard. Based on the response surface models, critical system variables were screened using F-tests, and then, the performance was approximated as a function of the variables because it is difficult to determine the performance of a high-order dynamic system as a function of system variables through analytical approaches. In this study, the conformance of uncertain performance to the specification was defined as a probability measure. The design variables obtained by optimizing the measure can provide actuator performance conforming to the specifications considered, even though there is a variation in both the components and the aero-induced disturbances.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.243-251
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• 1998

A method of establishing the tooth modification for gear transmission of vehicles to reduce gear whine noise, caused by tooth impact phenomenon of mating gear, is introduced. The major causes of tooth impact are due to the deflections of gear teeth and shafts of transmission with the loaded condition including various kinds of manufacturing errors. The theoretical shape of tooth surface to avoid tooth impact is derived by the amount of elastic deformation of gear teeth and shaft and overall manufacturing error of machine tool. The surface function is converted with respect to the conventional commercial data usually communicated to the gear inspection system. The proposed method is applied to the gearbox of four wheel drive vehicle and shows the gear whine noise decreased to the 8 dB in the sound level.