• 한국기계가공학회지
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• 제13권6호
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• pp.46-53
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• 2014

An automatic grease lubricator provides an adequate amount of fresh grease constantly to any type of rotating machine to minimize friction heat and reduce friction loss. This study seeks to develop an automatic grease lubricator by means of rapid prototyping with a gear-driven mechanism and a controlled operation time. The ultimate design is to lubricate an adequate amount of grease by a simple dip-switch clicking mechanism according to an advanced set cycle. The backlash of the gear was minimized to increase the power, and to increase the power of the mechanism, the binding frequency and the thickness of the coil were changed. To control the rotation cycles of the main shaft according to certain set numbers, different resistances and chips were used in the design of the circuit which controls the electrical signals via a pulse. A digital mock-up was analyzed and the rapid prototyping (RP) trial products were tested with a PCB circuit and grease. An evaluation of the outlet capacity of RP trial products was conducted, as the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, a finishing process was applied to decrease the roughness of a surface to a comparable level to test the performance of the product.

• 한국소음진동공학회논문집
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• 제12권12호
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• pp.921-928
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• 2002

Main sources of the nitration of a gear-pair system are backlash and transmission error, the difference between required and actual rotation during gear meshing. This paper presents the nonlinear dynamic characteristics of gear motions due to the existence of backlash and periodic variation of meshing stiffness, which is assumed as a one-term harmonic component. Gear motions are classified as three types with the consideration of backlash. Each response is calculated using the harmonic balance method and confirmed by numerical integration. The responses with the increase of the rotating speed show abrupt changes in its magnitude for the variation of the preload, exciting force, and damping coefficient. The result also shows that there is a chaotic motion with some specific design parameters and operating conditions In gear diving system. Consequently the design of gear driving system with low nitration and noise requires the study on the effects of nonlinear dynamic characteristics due to stiffness variation and backlash.

• 드라이브 ㆍ 컨트롤
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• 제16권2호
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• pp.15-21
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• 2019

In this study, the maximum system efficiency of the electro-hydrostatic actuators was experimentally investigated, where small size external gear pumps with volumetric displacement under 1.3 cc/rev were combined with a 400W servomotor as the prime mover. Since the efficiency data of the servomotor, gear pumps and hydraulic cylinder were not provided by the suppliers, experimental apparatuses for their efficiency measurement were extra built up. When a gear pump with a volumetric displacement of 1.27cc/rev was used on an electro-hydrostatic actuator system, the maximum system efficiency was not higher than 70%. This was because the most effective operation ranges of the motor and pump did not coincide each other. In order to match their operation ranges as one of the most crucial design factors, a speed reduction mechanism can be used, such as a timing belt. It was shown in the study that the maximum system efficiency could be increased from 70% to 76% in that way.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.237-246
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• 2019

전기기계식 제동장치(EMB : Electro Mechanical Brake)는 자동차 및 철도차량의 차세대 제동장치로서 현재 연구가 활발히 진행되고 있다. 현재의 고속열차용 제동장치는 공압 실린더를 이용하여 제동 압부력을 발생시키나 전기기계식 제동장치 (EMB)에서는 전기 모터 및 기어와의 조합을 통하여 압부력을 발생시킨다. 본 연구에서는 고압부력 발생이 가능한 EMB 구동 메커니즘을 제안하고, 해당 메커니즘을 만드는 기구장치 중 핵심부품인 기어 및 샤프트 부품들에 대한 구조 및 진동해석을 수행하였다. 한편 모델에 대한 동적 진동해석 결과 압부력이 가해진 상태에서 외부가진이 주어졌을 때 부재의 최대 응력이 항복강도 이내임이 확인되었다. 또한, 구조해석 결과 모터샤프트의 축 직경을 최대한 크게하는 설계가 강도 상 유리함을 확인하였으며, 기어와 편심샤프트를 고정하는 볼트에서 큰 전단응력이 발생할 수 있음을 확인하였다. 한편 해석모델의 메커니즘을 재현할 수 있는 시험장치를 제작하여 가장 취약한 부위인 고정 볼트부의 변형률을 구동 토크가 가해진 상태에서 측정하였다. 변형률 측정결과는 해석결과와 오차가 10% 이내로서, 해석모델의 정확도를 검증할 수 있었다.

• 대한기계학회논문집
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• 제8권1호
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• pp.86-94
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• 1984

본 연구에서는 최신형 슬란트베드(slant-bed)타입의 중절삭용 NC선반주축을 대상으로 하여, 구동방식의 변경-기어변속장치를 주축으로부터 완전히 분리시키고 V벨 트에 의해 구동되는 후로팅방식의 새로운 주촉구조를 설계-을 통하여 고속에서의 주축 의 회전성능 향상을 시도하였고, 실험을 통하여 그 회전성능을 전형적인 3개의 서로 다른 재래식 선반주축모델들의 값과 비교 고찰하였다.

• 한국가스학회지
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• 제18권6호
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• pp.45-50
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• 2014

본 논문에서는 산업기계 및 로봇산업에 적용할 수 있는 직선 정밀 이송 장치의 구동부를 설계하였다. 동력의 전달방향 및 출력특성은 기존의 Rack-Pinion 타입과 유사하나 구동부에 대하여 새로운 Pin-Pinion Gear 타입을 적용시켜 랙 모듈화를 통한 무한 길이 확장성을 구현하고 고속이송 및 설치의 편의성을 확보할 수 있으며 이러한 Pin-Pinion Gear의 최적물림을 위한 Cycloid 치형 해석을 하였다. 그 결과 Cycloid 치형으로 설계시 핀과 피니언 기어의 백래쉬 및 물림 특성이 적합하여 정밀제어가 가능한 치형으로 분석되었다.

• 한국정밀공학회지
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• 제30권11호
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• pp.1187-1192
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• 2013

In the case of 4 wheel drive (4-WD) type car, power switching occurs to 4-WD by operating lever or switch that operates power switching device attached in transfer case which can operate motor by electric signal. So if the RPM of motor is high, power switching will not exactly occur and can cause damage to gear in transfer case according to circumstances. So in this study, we applied 2 level of planet gear type motor spindle of motor drive part of a power train. And conducted decelerating to increase torque to switch power safe and accurately. Also, we researched efficiency of gear by designing reduction gear ratio and gear type and by calculating contact stress and bending strength. Based on researched content, we made drive head of power switching device and a reduction module which uses type that uses motor spindle as sun gear and ring gear as cover.

• 한국소음진동공학회논문집
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• 제21권10호
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• pp.951-959
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• 2011

In this study, an OTM(on-the-move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite while moving was addressed. Since LOS(line-of-sight) of antenna should direct satellite consistently while vehicle moving to guarantee high satellite communication quality, active antenna LOS stabilization is a core technology for OTM antenna. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. In consideration of driving mechanism which consists of gear train and flexible driving shafts, a two-mass-system dynamic model coupled with vehicle motion was presented. An internal PI-control loop + outer PI-control loop structure has been suggested in order to damp the torsional vibration and stabilize control system. The classical pole-placement method was applied to design control gains. In addition, a vehicle motion compensation control beside of the feedback control loop has been suggested to improve LOS stabilization performances. The feasibility of the proposed control design was verified along with some experimental results.

• 한국정밀공학회지
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• 제29권7호
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• pp.770-777
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• 2012

This paper deals with the design and modal characteristics analysis of a drive-train for a paralleltype hybrid electric vehicle (HEV). The function of the drive-train system (DTS) in the HEV combines or divides the torque and velocity from the internal combustion engine along with the induction motor. The system consists of a compound planetary gear and unit's electromagnetic clutch to provide the operation modes such as Engine Only (EO), Electric Vehicle (EV), and Hybrid Electric Vehicle (HEV) modes. In order to investigate the characteristics of the velocity and torque flow for the system, dynamic models of the HEV with DTS are derived from the prototype DTS. The performance of the derived dynamic models is evaluated by both computer simulations and experiments according to each mode.

• 연구논문집
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• 통권30호
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• pp.101-110
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• 2000

고속 Rapier loom에서 위사를 Insert rapier와 Carrier rapier로서 경사를 상부와 하부로 2구분한 개구속으로 투입하여 경사와 위사의 조직을 완성시키는 위입기구는 스크류 구동방식이다. 이는 래피어와 휠의 치수를 줄이고, 기어와 벨트가 없이 직접 주축에 연결하는 구조이다. 그러므로 래피어가 요구하는 어떠한 가속도 곡선이 가능하여 고속화와 가동률 향상에 최적으로 정확한 설계에의한 래피어 운동이 필수적이다. 따라서 본 연구는 전체 거동의 파악을 위한 시스템의 정확한 해석과 컴퓨터 시뮬레이션을 통한 Rapier loom의 고속화를 목적으로, 위입기구의 해석이론 정립 및 스크류의 회전에 따라 정확한 운동을 유도할 수 있도록 래피어의 변위, 속도 및 가속도 성분의 도출은 물론 동시에 화면상에 구현할 수 있는 스크류기구에 대한 시뮬레이션 프로그램을 개발하는 것이다.