• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.760-761
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• 2015

기어는 회전 기계 사이의 동력 전달을 위한 장치이며 현재 산업 전반의 통상적인 기어는 기계적 기어가 주류로서 형성되어 있다. 하지만 기계적 기어는 맞물린 톱니바퀴의 물리적 접촉에 의해 접촉 경계면의 마모 및 파손, 소음과 진동의 문제가 있으며 유지보수 비용 또한 크다. 따라서 최근 물리적 접촉이 없어 기계적 기어의 많은 문제를 해결할 수 있는 마그네틱 기어 (Magnetic Gear)에 대한 관심이 높아지고 있다. 마그네틱 기어는 영구자석에서 생성된 자계를 이용하여 비접촉 동력전달이 가능하며, 마찰손실 제거, 유지보수의 용이성, 매우 적은 소음 및 진동 등의 장점을 가지고 있다. 본 논문에서는 이러한 마그네틱 기어의 토크전달 방법과 형상변화에 따른 전달토크 특성을 2-D 유한요소해석법을 이용하여 해석하고 분석하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2706-2711
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• 1994

In this work, an experimental type of torque converter has been constructed and its characteristics have been evaluated by adapting an electrorheological fluid(ERF) as an operating medium. The device was designed by using the equations which were proposed by Carlson et al. The correlation between the rheological behaviour of an ERF and mechanical parameters of the clutch has been investigated. The torque generated by an ERF in this device is sum of one due to the yield strength by polarizing dispersed particles in dielectric oil and one due to the viscous drag. The experimental results are presented in terms of torque and current density as a function of rotational speed at various electric field strength applied. Experimental results showed that the measured torque was rapidly increased with the increase of the electric field, generally being proportional to the rotational speed of the motor. The measured current was shown to be increased with the increased electric field. Also, the current was decreased with the increase of increased with the increased electric field. Also, the current was decreased with the increase of the rotational speed of the motor and reached plateau region after f = 5 Hz.

• 기계와재료
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• v.24 no.2
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• pp.110-121
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• 2012

유압식 무단변속기(HCVT : Hydraulic Type Continuous Variable Transmission)는 유압펌프와 유압모터의 용적변화에 의하여 무단변속이 이루어지므로 내부구조가 간단하고 변속충격도 거의 없다. 그리고 유압펌프와 유압모터는 작동압력을 높임으로써 출력비와 토크를 크게 향상시킬 수 있다. 그러나 기존 변속기에 비하여 콤팩트한 장점은 있지만 동력전달효율이 다소 떨어진다. 그리하여 연비보다는 한정된 공간, 기동력, 그리고 고출력을 요구하는 중 대형차량의 차세대 변속기로 널리 활용된다. 본 연구에서는 선진국의 무단변속기에 대한 연구동향을 정리하고 국내에서 연구 개발이 진행되고 있는 유압식 무단변속기의 작동원리, 기계장치의 내부구조, 그리고 유압장치의 변속기능을 소개한다. 또한 기계동력전달과 유압동력전달에 관련된 수식들을 유도하고 다양한 동력조건에서 시뮬레이션을 수행하여 유압식 무단변속기의 내 외부에서 생성되는 토크, 속도, 동력 등의 각종 물리량들을 분석한다. 이러한 정보들은 구성부품들의 선정 및 설계에 유용한 자료로 활용된다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.19-19
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• 2004

햅틱장치는 가상환경이나 원거리에 있는 환경과 사용자가 상호 작용할 매 촉감이나 힘을 전달하는 장치이다. 사용자에게 힘을 제시하기 위한 액츄에이터는 모터와 브레이크가 많이 사용되는데, 각각의 특성에 맞게 제어하여 성능과 안정성을 동시에 만족시켜야 한다 모터와 같은 능동 액츄에이터는 토크를 원하는 방향으로 쉽게 출력할 수 있지만, 동작 중 불안정한 상태가 발생할 수 있다. 반면에 브레이크와 같은 수동 액츄에이터는 회전에 반대되는 방향으로만 토크를 발생시킬 수 있지만, 동작 중 에너지를 계속 소모하기 때문에 시스템이 본질적으로 안정하다.(중략)

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2033-2035
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• 2001

본 연구는 기존의 자전거에 전기 구동장치를 장착시켜서 자전거의 페달링에 의하여 검출된 답력을 이용한 보조 동력 구동장치에 대한 개발이다. 답력의 검출은 불시의치차를 이용한 동력 전달장치를 이용하였다. 이 장치의 입력기어에서 출력기어로 동력을 전달하는 아이들 피니언 기어와 결합된 캐리어를 동력 전달시 발생하는 반력에 의한 각도를 이용하여 토크량을 측정하였다. 동력전달을 할 경우 발생하는 반력에 의한 회전각을 자기센서를 이용하여 답력을 측정하였다. 이 답력을 구동회로에 인가하여 보조동력을 자전거에 인가함에 따라 주행을 쾌적하게 하도록 개발하였으며 실험을 통하여 실용성을 고찰하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.2
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• pp.241-247
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• 1998

The hydraulic coupling is a kind of power transmission device combined with pump turbine and casing as its main parts. The purpose of this research is to construct an experimental test set-up and to establish an available soft ware for th characteristics of two domestically developed hydraulic couplings. The test item is torgue rpm. and slip and or efficiency characteristic in accordance with variation of oil quantity. in this case the oil quantity was varied 55%, 67% and 77% of the inside capacity of hydraulic copuling.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1021-1027
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• 2006

Torque fluctuation of an engine and angular velocity variation of a propeller shaft are the main excitation sources in the vehicle driveline. This paper presents brief mechanism of these excitation sources. Equivalent models of these systems are construced to simulate the excitation source. The computer simulation was carried out by ARLA Simul v 6.7 and ARLA-Simstat v 2.3. Results of the simulations show the characteristics of torsional excitation source of the driveline. Experimental setups for engine system and propeller shaft system are constructed with component of the vehicle. Torque fluctuation of the flywheel and angular velocity of the propeller shaft were measured from this experimental setups. Experimental results are compared with simulation results. The results from experimental analysis agree with those from theoretical results.

• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.10-15
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• 2023

Wet multi-disk clutch, a power switching device of the ducted fan, was optimized and results were analyzed. The clutch was divided into two types depending on whether a mechanical lock-up was applied or not. It was optimized under each design condition. Transfer torque capacity, friction material surface pressure, friction surface temperature, and drag torque were calculated as factors to optimize the clutch. The volume of separator plate and drag torque were used as the objective function for optimization. In the case of Type 1, which did not include a mechanical lock-up, the clutch could be operated regardless of the pitch angle of the ducted fan. However, the outer diameter of the friction surface was doubled, the volume was increased by 5~7 times, and the drag torque was increased by 7~12 times compared to those of Type 2, which included a mechanical lock-up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.726-733
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• 2017

A magnetic shutter gear is a device that transfers mechanical power by synchronizing the magnetic field between permanent magnet layers facing circumferentially through a harmonic modulator. However, magnetic gears uses many rare-earth permanent magnets to guarantee comparable torque density to that of mechanical reducer. Hence, we propose a novel axial magnetic gear with a dramatically reduced number of permanent magnets and a closed magnetic path. The torque of the system was compared to that of an existing shutter gear through a harmonic analysis of the air-gap magnetic field. The modulator thickness and open ratio were considered as the primary design parameters, and the cogging effect was analyzed for variation of the reduction ratio. A dynamic model between the high-speed side and low-speed side was derived, and position control was performed for a constructed hardware implementation.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.471-474
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• 2009

Gearbox is used to converter the power with high torque and low speed into the power with low torque and high speed. Gearbox housing should be sustained to prevent rotation of gearbox itself due to the difference between input and out torque. Uneven wind causes the reaction system to have unwanted reactive loads together with predictable pure torque. These unwanted reaction loads often cause the failure of gearbox due to bad gear mesh. In this paper, pure torque reaction system is proposed to prevent the failure of gearbox. Effectiveness and functionality of the proposed reaction system are demonstrated through the numerical analysis.