• 드라이브 ㆍ 컨트롤
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• 제14권1호
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• pp.1-7
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• 2017

The power train of a concrete truck mixer reducer includes differential planetary gears to get a large reduction ratio for operating the mixer drum in a compact structure. These differential planetary gears are a very important part of the mixer reducer where strength problems are the main concern. Gear bending stress, gear compressive stress and scoring failure are the main concerns. Many failures in differential planetary gears are due to the insufficient gear strength and resonance problems caused by major excitation forces such as gear mating failure in the transmission. In the present study, where the excitation frequencies are the gear tooth passing frequencies of the mating gears, a Campbell diagram is used to calculate differential planetary gear critical speeds. Mode shapes and natural frequencies of the differential planetary gears are calculated by CATIA V5. These are used to predict gear resonance failures by comparing the working speed range with the critical speeds due to the gear transmission errors of the differential planetary gears.

• Journal of Biosystems Engineering
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• 제22권4호
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• pp.497-502
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• 1997

Automation facilities of greenhouses have been continuously developed. However, the conventional two-stage worm gear reducer reveals some problems, including low transmission efficiency. The worm gear reducer also have some difficulties in manufacturing and short life. Therefore, this study was performed to develop a planetary gear reducer, having a high Sear reduction ratio and high torque transmission efficiency. The planetary gear system consisted of a fixed ring gear and a 2-teeth differential ring gear turning slow, as the planetary pinion orbits fast around the fixed ring gear. The developed gear system can achieve a high speed reduction rate at one stage. The reducing system was employed to the greenhouse ventilation system. The reducer has the transmission efficiency of 70.5%, 2∼3 times longer life time, and twofold roll-up torque at an affordable price, comparing with conventional reducers. This reducer can be also applied to many industrial equipments, such as industrial crane, hoist, elevator and gondola etc.

• 한국가스학회지
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• 제24권6호
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• pp.55-60
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• 2020

세계적으로 친환경자동차의 연구 및 개발이 확대되면서 주행거리를 증대시키기 위해 차량의 부가적인 장치를 축소·삭제하거나 경량화를 위한 연구를 진행하고 있다. 그 중 내연기관자동차에 적용되던 다단변속기를 삭제하고 감속기로 대체하여 모터출력 값 제어를 통해 토크증대로 초기구동력을 확보하고 있다. 하지만 잦은 모터의 속도변화로 부하가 상승되는 결과를 가져올 수 있기 때문에 본 연구에서는 일반적인 감속기구조를 갖는 소형·경량의 수동 2단 감속기를 개발하려고 한다. 따라서 평행축을 갖는 구조에 대기어와 소기어를 삽입하여 평행한 축의 감속기형태에서 V-벨트로 기어를 연결하고, 저단과 고단의 기어비를 각각 설정하여 2개의 기어비를 갖는 2단 변속기를 설계하였다. 또한 변속기의 회전속도와 부하에 따른 동력성능을 시험을 통해 확인하고 구동시 발생되는 발열특성을 확인하여 변속기의 타당성을 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.101-105
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• 2004

The traction drive have a high power transmission efficiency and small size, a light weight, a low noise. So it is expected that alternative drive part of engine. Because it is necessary stillness that essential condition of drive part used moving tool in a room, it has many-sided in field of application. This traction drive is better suitable than other speed reducer as drive part of electric wheelchair. Also it is sufficiently necessary capacity of existing advanced product as apply traction drive to electric wheelchair.

• 한국생산제조학회지
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• 제24권3호
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• pp.348-354
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• 2015

Using a magnetic gear, the speed and torque of the driving axis can be decreased and increased, respectively, similar to a mechanical speed reducer. In particular, because the driving side can be isolated mechanically from the load side, the magnetic gear was developed for application with environmental constraints. Of the existing topologies used for the magnet gear, the filtering method of a specified magnetic component is the most competitive. In this paper, a novel unified harmonic modulator is applied to filter the specified component. The torque conversion method using this modulator is described in detail, and the key factors of the modulator are derived from the influence on the resulting torque. The experimental setup was constructed and its torque transmission efficiency measured for varying loads. The transient characteristic from an excessive load is compared with the theoretical simulation.

• 열처리공학회지
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• 제36권5호
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• pp.311-317
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• 2023

An autofilter is a device that removes impurities contained in heavy fuel oil used in diesel engines of ships or power plants, and also automatically removes impurities accumulated in the filter through a reverse washing function. The reducer-integrated motor serves to rotate the filter at low speed to enable reverse automatic cleaning in the autofilter device. To achieve a low speed of 0.65 to 0.75 rpm in a reducer-integrated motor, a small motor that can operate at 97rpm at a rated voltage of 110 V and 112.5 rpm at 220 V is required. Additionally, a large gear ratio of 1/150 is required. To ensure the durability and reliability of these reducers, the strength of the gear must be evaluated at the design stage. In general, there is a limit to evaluating the stress and strain state according to the vibration characteristics acting on each gear in the driving state of the reducer through quasi-static analysis. Therefore, in this study, the operation characteristics of the auto filter's reducer-integrated motor were first analyzed using the rigid body dynamics analysis method. Then, this rigid body dynamics analysis model was extended to a flexible multibody dynamics analysis model to analyze the stress and strain states acting on each gear and evaluate the design feasibility of the gear.

• Journal of Advanced Marine Engineering and Technology
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• 제39권9호
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• pp.895-902
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• 2015

본 연구에서는 사이클로이드기어시스템 1단, 한 쌍의 평기어시스템, 입력 축, 출력 축, 하우징으로 구성되어 있는 2MW급 풍력발전기용 사이클로이드 피치감속기에 대해 유한요소해석을 통한 안정성평가를 수행하였다. 또한 평기어에 대해서는 ISO 6336에 의한 기어강도해석을 통하여 안정성 여부를 평가하였다. 2MW급 풍력발전기용 사이클로이드 감속기의 고유진동 특성 해석을 수행하였고, 입력축 질량불평형, 출력축 질량불평형, 평기어 치합전달오차, 사이클로이드기어 치합전달오차 등에 발생하는 가진원에 대해 위험속도 분석을 하였다.

• 한국기계가공학회지
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• 제16권3호
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• pp.63-68
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• 2017

In order to process more complicated and higher-precision parts, generally, an additional axis for a machine tool is needed which was an approach to minimize the cost of tool modification. A table with a rotary reducer that can rotate through the axis of the gear system was employed to a machine tool to achieve the purpose of adding an extra motion axis. In general, the motion of the rotary reducer is driven by a worm/wheel or helical gear system, which is different from the hypoid helical gear structure that used in this research. Reliability of guarantee of high accurancy throughout the whole life cycle is on of the critical factors to evaluate a rotary reducer in this field. In this paper, in order to evaluate life-time of rotary reducer, a low-cost accelerated life test was developed to satisfy the demands of clients.

• 한국기계가공학회지
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• 제11권2호
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• pp.55-59
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• 2012

This study performs the bending and contact stress analyses for a pair of mating gears during rotation. The interested gears are used for a railway reducer. In general, the railway reducer needs high speed rotation, which leads to a large gear ratio. Thus, it is not easy to apply finite element method to investigate the strength performance, since the size of a gear is much larger than that of a pinion. In this study, the bending and contact stresses determined from FEM are compared with the values determined from the ISO code.

• 한국산업융합학회 논문집
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• 제26권6_3호
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• pp.1223-1231
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• 2023

In the case of internal combustion engine vehicles, transmissions are essential for various reasons, such as vehicle starting and speed control. However, in the case of electric vehicles, unlike internal combustion engine vehicles, a transmission is not necessarily required. Of course, considering the efficiency of electric vehicles, a transmission is necessary, but installing the existing transmission as is has the opposite effect due to increased vehicle weight, so it has not been considered so far. In this paper, a non-contact reducer type using the Arago disc effect is proposed rather than a transmission using a conventional gear train, and the aim is to examine whether this can increase the driving efficiency of electric vehicles while minimizing weight. In addition, the effectiveness of the proposed reducer will be verified by manufacturing and testing it.