The Experts below are selected from a list of 603 Experts worldwide ranked by ideXlab platform
Herbert S. Cheng - One of the best experts on this subject based on the ideXlab platform.
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Sliding Wear Calculation in Spur Gears
Journal of Tribology, 1993Co-Authors: Herbert S. ChengAbstract:In gear applications where precipitous tooth failure mode such asscoring or scuffing has been avoided, «normal» wear becomes a life-determining factor. In this paper, sliding wear in spur gears, including the considerations of gear dynamics and rough elastohydrodynamic lubrication, is analyzed. Formulas for equivalent wear rate and tooth wear profile along the line of action are derived. Results show that most materials are removed from both the addendum and Dedendum tooth surfaces, and that the highest wear occurs at the beginning of an engagement. This high wear region corresponds to the root of the driving (pinion) teeth and the tip of the driven (gear) teeth. These analytical results correlate well with the practical evidences in AGMA documentation
Zhi-jing Feng - One of the best experts on this subject based on the ideXlab platform.
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design of an ackermann type steering mechanism
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2013Co-Authors: Jing-shan Zhao, Zhi-jing FengAbstract:This article focuses on the synthesis of a steering mechanism that exactly meets the requirements of Ackermann steering geometry. It starts from reviewing of the four-bar linkage, then discusses the number of points that a common four-bar linkage could precisely trace at most. After pointing out the limits of a four-bar steering mechanism, this article investigates the turning geometry for steering wheels and proposes a steering mechanism with incomplete noncircular gears for vehicle by transforming the Ackermann criteria into the mechanism synthesis. The pitch curves, addendum curves, Dedendum curves, tooth profiles and transition curves of the noncircular gears are formulated and designed. Kinematic simulations are executed to demonstrate the target of design.
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Original Article Design of an Ackermann-type steering mechanism
2012Co-Authors: Jing-shan Zhao, Zhi-jing Feng, Xiang Liu, Jian S DaiAbstract:This article focuses on the synthesis of a steering mechanism that exactly meets the requirements of Ackermann steering geometry. It starts from reviewing of the four-bar linkage, then discusses the number of points that a common four-bar linkage could precisely trace at most. After pointing out the limits of a four-bar steering mechanism, this article inves-tigates the turning geometry for steering wheels and proposes a steering mechanism with incomplete noncircular gears for vehicle by transforming the Ackermann criteria into the mechanism synthesis. The pitch curves, addendum curves, Dedendum curves, tooth profiles and transition curves of the noncircular gears are formulated and designed. Kinematic simulations are executed to demonstrate the target of design
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//blrnas3/cenpro/ApplicationFiles/Journals/SAGE/3B2/PICJ/Vol00000/130161/APPFile/SG-PICJ130161.3d (PIC) [INVALID Stage] Original Article Design of an Ackermann-type steering mechanism
2012Co-Authors: Jing-shan Zhao, Zhi-jing Feng, Xiang Liu, Jian S DaiAbstract:This article focuses on the synthesis of a steering mechanism that exactly meets the requirements of Ackermann steering geometry. It starts from reviewing of the four-bar linkage, then discusses the number of points that a common four-bar linkage could precisely trace at most. After pointing out the limits of a four-bar steering mechanism, this article inves-tigates the turning geometry for steering wheels and proposes a steering mechanism with incomplete noncircular gears for vehicle by transforming the Ackermann criteria into the mechanism synthesis. The pitch curves, addendum curves, Dedendum curves, tooth profiles and transition curves of the noncircular gears are formulated and designed. Kinematic simulations are executed to demonstrate the target of design
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Design of a pair of noncircular gears meeting Ackermann steering principle
2011 International Conference on Consumer Electronics Communications and Networks (CECNet), 2011Co-Authors: Sheng Zhao, Jing-shan Zhao, Zhi-jing FengAbstract:This paper focuses on the design of a pair of noncircular gears, which is used in a concept automobile steering system to make the steering meet Ackermann steering principle. Based upon Ackermann steering principle, the pitch curves of the noncircular gears are formulated. The tooth profiles, addendum and Dedendum curves, and transition curves of the noncircular gears are designed. Moreover, the phenomenon of the tooth profile reflection is discussed. Three-dimensional model of the noncircular gears is developed in Pro/ENGINEER, where a motion simulation is also carried out to prove the design.
Chul Kim - One of the best experts on this subject based on the ideXlab platform.
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Prediction of the dimensional deformation of the addendum and Dedendum after the warm shrink fitting process using a correction coefficient
International Journal of Automotive Technology, 2012Co-Authors: J. H. Bae, J. S. Kim, B. C. Hwang, W. B. Bae, M. S. Kim, Chul KimAbstract:The warm shrink fitting process is generally used to assemble automobile transmission parts (shafts/gears). However, this process causes a deformation in the addendum and Dedendum of the gear depending on the fitting interference and gear profile, and this deformation causes additional noise and vibration between the gears. To address these problems, the warm shrink fitting process is analyzed by considering the error in the dimensional deformation of the addendum and Dedendum found when comparing the results of a theoretical analysis and finite element analysis (FEA). A correction coefficient that reduces this error is derived through an analysis of the difference in the cross-sectional area between the shapes used for the theoretical analysis and that of the actual gear, and a closed-form equation to predict the dimensional deformation of the addendum and Dedendum is proposed. The FEA method is proposed to analyze the thermal-structural-thermal coupled field analysis of the warm shrink fitting process (heating-fitting-cooling process). To verify the closed-form equation using the correction coefficient, measurements are made of actual helical gears used in automobile transmissions. The results are in good agreement with those given by the closed-form equation.
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a prediction of the amount of dimensional deformation of addendum and Dedendum after shrink fitting process
Journal of the Korean Society for Precision Engineering, 2011Co-Authors: Jisan Kim, Beamcheal Hwang, Wonbyong Bae, Chul KimAbstract:The warm shrink fitting process is generally used to assemble automobile transmission parts (shaft/gear). But the fitting process can cause the dimensions of addendum and Dedendum of the gear to change with respect to the fitting interference and the profile of the gear. As a result, there may be additional noise and vibration between gears. To address these problems, we analyzed the warm shrink fitting process according to process parameters; the fitting interference between the outer diameter of the shaft and the inner diameter of the gear, the inner diameter of the gear, addendum and Dedendum of the gear, the heating temperature. In this study, a closed form equation for predicting the amount of deformation of addendum and Dedendum in the R-direction was proposed. And the FEA method to analyze the cooling process was proposed for thermal-structural-thermal coupled field analysis of the warm shrink fitting process (heating-fitting-cooling process).
Zhi Jun Zhang - One of the best experts on this subject based on the ideXlab platform.
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Virtual Design and Structural Optimization of Dry Twin Screw Vacuum Pump with a New Rotor Profile
Applied Mechanics and Materials, 2009Co-Authors: Shi Wei Zhang, Zhi Jun ZhangAbstract:Twin screw vacuum pump is an important kind of dry vacuum pump, which is widely used in the oil-free vacuum system. The design of the screw rotor profile directly influences the working performance and manufacture cost of the screw pumps. In this paper, a new rotor profile for twin screw vacuum pump is introduced which is comprised of the cycloid curve, the Dedendum circle arc, the involute curve and the addendum circle arc. The processes of three-dimensional modeling, motion simulation, interference checking and structural optimization for twin screw vacuum pumps are studied by means of Solidworks software. The works provide theoretical basis for optimal designing and reference for test prototype manufacturing. The results showed the performance of the vacuum pump according with the designer’s intention.
Shizhe Feng - One of the best experts on this subject based on the ideXlab platform.
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Lubrication reliability analysis of spur gear systems based on random dynamics
Tribology International, 2021Co-Authors: Jiaxing Pei, Xu Han, Yourui Tao, Shizhe FengAbstract:Abstract An approach for lubrication reliability analysis of spur gear systems considering the randomness of external load and surface roughness is presented. The instantaneous failure probability of gear lubrication is captured by a gear stochastic dynamics model and a reliability model of elastohydrodynamic lubrication (EHL). The stochastic dynamics model is adopted to obtain the numerical characteristics of meshing force. The reliability model is established based on a mixed EHL line contact film thickness formula. The first-order second-moment method is employed for predicting failure probability of lubrication. The lubrication reliability of a gear pair excited by different intensity random load is studied. The results show that the lubrication failure probability in Dedendum and single meshing region are higher than addendum.
