• 한국자동차공학회논문집
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• 제16권6호
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• pp.97-103
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• 2008

In general, the strength of gears is calculated using the formula of AGMA or JGMA. But these formula can not be applied directly to the strength calculation of the rack and pinion of steering gear assay, because of complex tooth and contact shapes. So Lewis bending stress and Hertzian contact stress formula are generally used for the design of rack and pinion of steering gear assay. But these formula do not also give the exact stress of rack and pinion. In this paper, comparing the finite element analysis results and the experimentally measured values, it is shown that the finite element modeling technique of the rack and pinion of steering assay is reasonable.

• 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.

• 동력기계공학회지
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• 제14권3호
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• pp.64-70
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• 2010

In this study, designing of precise linear transferring device which can be applied to industrial machine and robot industry has been introduced. The direction of power flow and output feature are similar to current Rack-Pinion type. However, unlimited length extensity via rack modulizing, and securing high velocity transportation have been realized by applying Pin-Pinion Gear type at the operation part. The analysis has been calculated to obtain the Pin-Pinion Gear's optimized tooth profile. As a result of research, it is impossible to control precisely even overlap at the teeth of involute and sprocket. Because they have peculiar gearing structure. Therefore, modified cycloid tooth has been proposed to perform high velocity, precise control without backlash.

• 한국생산제조학회지
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• 제5권3호
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• pp.40-49
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• 1996

The problem related to the rotational vibration at steering wheel end of passenger cars during high speed driving is investigated. to analyze vibration of steering wheel, a steering system of passenger car is modelled in twelve degrees of freedom including backlash effect of rack and pinion gear system. The one degree of freedom system with backlash in investigated by the analytical method. Consequently the skeleton curve and the frequency response curves are computed. The steering system is analyzed by the numerical simulation using the 4th order Runge-Kutta method, the obtained results are compared with the experimental data. Also the effects of the change of rack gear tooth stiffness and backlash on the acceleration level of steering wheel are investigated. As a result, it can be found that the acceleration level of steering wheel becames lower as the rack gear tooth stiffness becames higher, and that acceleration level becames high as the magnitude of backlash between rack and pinion gear increase.

• 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.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.1-6
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• 2010

This study presents the practical design modification to improve the retracting performance of the pyro-typed high power pretensioner. 3 components of the pretensioner are redesigned and the usefulness of the design modification is verified by the experiment. During the pretensioning process, the gas blast generated from the gunpowder is transferred to the rack-pinion gear through the manifold. The rack-pinion gear is connected with the spool where the webbing is rolled up. According to the rotation of the pinion, the spool is turned and the webbing is winded. To help the gas blast flow well, the shape of the inner cross section of the manifold is changed. The spur gear design program is developed and used to find the best combination of the rack-pinion gear pair to increase the power transmission efficiency. The pinion guide is installed on the spool to prevent the vibration of the pinion. As a result of the experiment, the amount of the web retraction length is increased when every single design modification is applied. Therefore, the retracting performance of the pretensioner is considered to be improved if the presented design modifications are applied.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.747-748
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• 2008

• 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.

• 한국안전학회지
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• 제12권4호
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• pp.39-46
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• 1997

This study describes a computer aided design system on involute gear for power transmition. Input data for gear design are pressure angle $20^{\circ}$, transmitted power, gear volume, gear ratio, addendum ratio of rack, dedendum ratio of rack, edge radius of rack, allowable contact stress and allowable bending stress etc. Bending strength contact strength and scoring are considered as the design constraints. Method of optimization developed this study. The developed gear design system can design the optimized gear that minimize the number of pinion teeth with face tooth.

• Tribology and Lubricants
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• 제30권4호
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• pp.212-217
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• 2014

A counter gear transmits the rotation angle, so the angular velocity ratio of the gear does not necessarily need to be constant in the meshing process. As a pinion has a small number of teeth when combined with an internal gear for counters, tooth interference can occur with the use of an involute curve. This paper introduces circular arcs that represent a tooth profile and fillet for the profile design of a pinion through the combination of arcs with lines. The straight line of a rack tooth represents the profile of a mating internal gear. Thus, the circular arc and line maintain contact during the rotation of the counter gear. This paper presents an analysis of the meshing of the circular arc tooth and rack tooth along with the properties of the counter gear, such as the change in rotational velocity and amount of backlash. The contact ratio of the counter gear is 1 because the tooth contact occurs between circular arcs and line. The initial position of tooth contact, which denotes the simultaneous contact of two teeth, is found. As the rotation of the pinion, only one tooth keeps the contact situation. This meshing property is analyzed by the geometrical constraints of the tooth profile in contact and the results are presented as graphical diagrams in which tooth-arc movements are superimposed.