• 한국생산제조학회지
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• 제21권5호
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• pp.702-707
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• 2012

This paper considers two linear drive systems using roller gear mechanism(RGM), one is the RRP(roller rack pinion) system that consists of a roller rack and a cam pinion, the other is the CRP(cam rack pinion) system that consists of a cam rack and a roller pinion. Through the comparison of contact forces and load-stress factors between two linear drive systems, it reveals that the RRP system is superior to the CRP system in the aspect of the bending strength, while the CRP system has higher contact fatigue resistance than that of the RRP system.

• 한국생산제조학회지
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• 제26권3호
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• pp.299-305
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• 2017

Gate-lifting devices in small- to mid-sized sluice gates mostly employ the mechanical roller rack pinion (RRP) system. This RRP system, which consists of a rack-bar and a pinion, transforms a rotation motion into a linear one. The rack-bar has a series of roller trains that mesh with the pinion. In this study, we adopt an exact involute-trochoid tooth profile of the pinion to obtain a higher contact fatigue strength using the profile modification coefficient. Further, we determine the contact forces and investigate Hertz contact stresses to predict the pitting life of the pinion according to varying the shape design parameters. The results indicate that the design fatigue life of an RRP system for sluice gate can be achieved only when the design value of the profile modification coefficient reaches or exceeds a certain level.

• 한국생산제조학회지
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• 제21권2호
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• pp.283-289
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• 2012

Cam rack pinion (CRP) system which consists of cam rack and roller pinion transforms the rotation motion into linear one. The roller pinion has the plurality of rollers and meshes with its conjugated cam rack. The exact tooth profile of the cam rack and the non-undercut condition to satisfy the required performance have been proposed by introducing the profile shift coefficient. The load stress factors are investigated by varying the shape design parameters to predict the gear surface fatigue limit which is strongly related to the gear noise and vibration at the contact patch. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.

• 한국생산제조학회지
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• 제23권2호
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• pp.194-198
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• 2014

In recent years, RGM(roller gear mechanism) systems, wherein one of the gears of a meshing gear pair is replaced with pins or rollers, have been reintroduced, which is a consequence of, and therefore a reflection of, the rapid advances made in manufacturing technology. Three RTG(roller track gear) systems for arbitrary path transportation (e.g., L-, O-, U-, and S-shaped tracks) were constructed using two out of three RGM systems, namely, the CRP(cam rack pinion), CRG(cam ring gear), and RPG(roller pinion gear) systems, and are introduced in this paper. We also present three ways to prevent the intersection and non-contact phenomena at the teeth in the vicinity of the conversion point between two joined RGM systems.

• 대한기계학회논문집A
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• 제36권4호
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• pp.387-393
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• 2012

본 논문에서는 기존 랙-피니언 시스템의 랙 치형을 핀 또는 롤러로 대체한 롤러 랙 피니언 (RRP) 시스템의 표면피로 향상방안을 고찰하였다. 우선 전위계수(profile shift coefficient)를 고려하여 RRP 시스템의 캠 피니언(cam pinion)에 대한 엄밀 치형설계 방법 및 언더컷 방지 조건을 소개하였고, 이를 바탕으로 설계인자의 변화에 따른 하중 및 하중응력계수(load stress factor)의 변화를 검토하였다. 이를 통해 RRP 시스템의 표면 내구성을 향상시킬 수 있는 방안으로 전위계수의 증가가 효과적임을 알 수 있었다.

• 한국생산제조학회지
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• 제21권1호
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• pp.95-101
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• 2012

An internal type roller ring gear(RRG) system composed of either a pin or a roller ring gear and its conjugated cam pinion can improve the gear endurance from that of a conventional gear system by reducing the sliding contact, while increasing the rolling motion. In this paper, we first proposed the exact cam gear profile and the self-intersection conditions obtained when the profile shift coefficient is introduced. Then, we investigated contact stresses and surface pitting life to fmd characteristics for surface fatigue by varying the shape design parameters. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.715-716
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• 2012

• 대한기계학회논문집A
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• 제35권11호
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• pp.1453-1459
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• 2011

외접기어의 어느 한쪽 기어를 핀 또는 롤러로 대체한 롤러 피니언 기어 (RPG) 시스템은 기어 치물림 시 미끄럼 접촉을 줄이고 구름운동을 증대시켜 기어 내구성을 향상시킬 수 있다. 우선 본 논문에서는 전위계수(profile shift coefficient)를 고려하여 RPG 시스템의 캠 기어(cam gear)의 엄밀 치형설계 방법 및 치 꼬임으로 인한 간섭 방지조건을 제시하였다. 또 기어구동에 있어 치면에서 발생되는 진동이나 소음의 원인이 되는 피팅(pitting) 발생수명을 고려하기 위해, 설계인자의 변화에 따른 Hertz 접촉응력 및 하중응력계수(load stress factor)의 변화를 검토하였다. 이를 통해 RPG 시스템의 내구성을 향상시킬 수 있는 방안으로 전위계수의 증가를 제안하였다.

• 한국생산제조학회지
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• 제21권2호
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• pp.316-323
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• 2012

In order to meet the service life of planetary gearbox, a planet bearing, well known as the component with the highest failure rate, is designed. To predict the bearing fatigue life, ISO standard(ISO/TS 16281) is used, and the design parameters of the bearing are optimized using a parametric method. The whole planetary gearbox model is developed using a commercial software to calculate loads acting on planet bearings accurately. The results state that the designed bearings are satisfied with the life of 15,000hours, and the bearings that consist of 22rollers of 58mm have 1.6times longer life and better load sharing relatively than 22rollers of 28.5mm. Also, the increase in preload of taper roller bearings on the output pinion shaft prolongs the life of planet bearings regardless of roller's length.

• 한국전기전자재료학회논문지
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• 제37권1호
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• pp.106-111
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• 2024

A triboelectric nanogenerator is a promising energy harvester operated by the combined mechanism of electrostatic induction and contact electrification. It has attracting attention as eco-friendly and sustainable energy generators by harvesting wasting mechanical energies. However, the power generated in the natural environment is accompanied by low frequencies, so that the output power under such input conditions is normally insufficient amount for a variety of industrial applications. In this study, we introduce a non-contact rotational triboelectric nanogenerator using pedaling and gear systems (called by P-TENG), which has a mechanism that produces high power by using rack gear and pinion gear when a large force by a pedal is given. We design the system can rotate the shaft to which the rotor is connected through the conversion of vertical motion to rotational motion between the rack gear and the pinion gear. Furthermore, the system controls the one directional rotation due to the engagement rotation of the two pinion gears and the one-way needle roller bearing. The TENG with a 2 mm gap between the rotor and the stator produces about the power of 200 ㎼ and turns on 82 LEDs under the condition of 800 rpm. We expect that P-TENG can be used in a variety of applications such as operating portable electronics or sterilizing contaminated water.