• Title/Summary/Keyword: Rack and pinion

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A Strength Analysis of Rack and Pinion of Steering Gear Assay using a Commercial Finite Element Program (상용 유한 요소 프로그램을 이용한 차량 조향 장치의 랙과 피니언의 강도 해석)

  • Sung, Kee-Woong;Lim, Jang-Keum
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.6
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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.

Linear Drive Systems using Roller Gear Mechanism (롤러 기어 메커니즘을 이용한 직선이송시스템)

  • Kim, Chang-Hyun;Nam, Hyoung-Chul;Kwon, Soon-Man
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.5
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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.

Contact Fatigue Life of Rack-Pinion for Small-Sized Sluice Gate (소형 수문용 랙-피니언의 접촉 피로수명)

  • Kwon, Soon-man
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.3
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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.

Pitting Life of CRP System (CRP 시스템의 피팅수명)

  • Kim, Chang-Hyun;Nam, Hyoung-Chul;Kwon, Soon-Man
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.2
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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.

A Study on Optimum Tooth Profile of Pin-Pinion Gear for Linear Motion (직선이송용 Pin-Pinion Gear의 최적 치형에 대한 연구)

  • Ham, S.H.;Nam, W.K.;Oh, S.H.
    • Journal of Power System Engineering
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    • v.14 no.3
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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.

Vibration Analysis of a Rack and Pinon Typed Feed Drive System for a 5-Head Router Machine (Rack/Pinon 방식의 5-Head 라우터 머신 이송 시스템의 진동해석)

  • Choi, Y.H.;Choi, E.Y.;Jang, S.H.;Ha, J.S.;Cho, Y.H.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.269-272
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    • 2005
  • In order to prevent a router machine feed drive system from transient operational vibration, this paper presents vibration analysis of a rack and pinion typed feed drive system for a router machine. The feed drive system was mathematically idealized as a 5-degree-of-freedom lumped parameter model. Stiffness parameters of motor-shaft, rack and pinion gears, and machine structure were appropriately considered in the modeling. Computational experiment was carried out to obtain vibrations of the feed drive system during its transient speed operation.

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Dynamic Analysis of Vehicle Steering System Including Gear Backlash (기어의 백래쉬를 고려한 승용차 조향계의 동특성 연구)

  • 김종관
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.5 no.3
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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.

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Experimental Study to Improve the Performance of the Pretensioner for a Passenger Vehicle (자동차용 프리텐셔너의 성능향상을 위한 실험적 연구)

  • Jung, Sung-Pil;Park, Tae-Won;Song, Taeck-Rim
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.2
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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.