The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
G Muthuveerappan - One of the best experts on this subject based on the ideXlab platform.
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investigation of load carrying capacity of asymmetric high contact ratio spur gear based on load sharing using direct gear design approach
Mechanism and Machine Theory, 2016Co-Authors: Priya Marimuthu, G MuthuveerappanAbstract:Abstract The Direct Gear Design® approach is one of the many gear designing methods available to improve load carrying capacity of the gear pairs. For customized gear pairs, the direct gear design approach is more advantageous over conventional design. In this paper, a parametric study is carried out for asymmetric high contact ratio spur gears based on load sharing method to determine the improvement in load carrying capacity. A finite element model for multi-pair contact is adopted to determine the non-dimensional fillet and contact stresses which quantify the load carrying capacity of the gear pairs. The results of direct designed symmetric and asymmetric high contact ratio spur gears are compared with the conventional symmetric high contact ratio spur gears. Also, the influence of gear parameters such as addendum Pressure Angle, gear ratio, teeth number and backup ratio of non-dimensional stresses is analyzed in detail. The results show significant improvement in gear pair performance for all parameters analyzed.
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design of asymmetric normal contact ratio spur gear drive through direct design to enhance the load carrying capacity
Mechanism and Machine Theory, 2016Co-Authors: Priya Marimuthu, G MuthuveerappanAbstract:Abstract Maximum fillet and contact stresses of asymmetric normal contact ratio spur gears designed by direct design method are evaluated based on the load sharing ratio, using finite element method. For a direct gear design, area of existence diagrams are developed for known input gear parameters such as number of teeth, coefficient of asymmetry, top land thickness coefficient and drive side contact ratio. A unique Ansys parametric design language code is developed to find the load sharing ratio, maximum fillet and contact stresses. The fillet stress is calculated in terms of non-dimensional stress. The influence of gear drive parameters such as drive and coast side Pressure Angles, top-land thickness coefficients, contact ratio, coefficient of asymmetry, gear ratio and teeth number on load carrying capacity has been studied extensively on non-dimensional fillet stress and maximum contact stress and compared with that of the conventionally designed gears. Through parametric study, suitable suggestions are made for the design of asymmetric gear drive for an enhanced load carrying capacity with constant contact ratio and constant drive side Pressure Angle separately.
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estimation of tooth form factor for normal contact ratio asymmetric spur gear tooth
Mechanism and Machine Theory, 2015Co-Authors: Prabhu R Sekar, G MuthuveerappanAbstract:Abstract To estimate the tooth form factor for a loaded symmetric spur gear tooth, some normalized standards like International Organization for Standardization (ISO) and American Gear Manufacturers Association (AGMA) are available. However, the tooth form factor for a loaded asymmetric spur gear tooth cannot be estimated through the available standards. An asymmetric spur gear tooth is one whose drive side Pressure Angle is different from the coast side Pressure Angle. In the present work, the standard ISO B methodology has been adapted suitably for estimating the tooth form factor and the stress correction factor in asymmetric spur gear tooth. Also, the critical root fillet parameters (critical root tooth thickness, bending moment arm and radius of curvature) and the tooth form factor for asymmetric spur gear tooth with several sets of drive side and coast side Pressure Angles are determined through an adapted ISO method and a comparative study with FEM is also carried out.
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a balanced maximum fillet stresses on normal contact ratio spur gears to improve the load carrying capacity through nonstandard gears
Mechanics Based Design of Structures and Machines, 2015Co-Authors: Prabhu Sekar, G MuthuveerappanAbstract:This article presents an idea to remove the inequality in maximum fillet stresses developed between pinion and gear of a step up gear drive. This uniform fillet strength of the gear drive can be achieved by using nonstandard pinion and gear with appropriate addendum modifications generated by nonstandard basic racks of respective tooth thickness not equal to 0.5πm at the pitch circle. The influence of gear parameters such as gear ratio, Pressure Angle, addendum factor, pinion teeth number, and addendum modifications on the maximum fillet stress on the nonstandard pinion and gears of different tooth thickness has been analyzed through finite element method and finally the optimum value of rack tooth thickness coefficients (k pc and k gc ) are suggested for the given gear drive (defined by i) that improves the fillet capacity in bending. This study has been extended for various drives like S std , S o , S +, and S − drives.
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effect of addendum height and teeth number on asymmetric normal contact ratio spur gear based on load sharing
Universal Journal of Mechanical Engineering, 2014Co-Authors: Priya Marimuthu, G MuthuveerappanAbstract:This study explores the influence of some gear parameters such as addendum height, teeth number and module on load sharing aspect and the subsequent stress analysis. The multi pair contact model in finite element technique is used for a reasonable accurate prediction of the stresses with the application of load at high Pressure Angle side. Also, a unique Ansys parametric design language code is developed for this study. Finally the increase in addendum height results to increase the bending stress for a load at critical loading point. However the increase in teeth number and module leads to decrease in the load sharing based bending and contact stresses.
Chung-biau Tsay - One of the best experts on this subject based on the ideXlab platform.
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a novel finish hobbing methodology for longitudinal crowning of a helical gear with twist free tooth flanks by using dual lead hob cutters
ASME 2014 International Mechanical Engineering Congress and Exposition, 2014Co-Authors: Vanthe Tran, Rueihung Hsu, Chung-biau TsayAbstract:In the gear finish hobbing process, to obtain a twist-free tooth flank of helical gears, a novel hobbing method for longitudinal crowning is proposed by applying a new hob’s diagonal feed motion with a dual-lead hob cutter. Wherein the hob’s diagonal feed motion is set as a second order function of hob’s traverse movement and tooth profile of hob cutter is modified in a dual-lead form with Pressure Angle changed in it’s longitudinal direction. The proposed method is verified by using two computer simulation examples to compare topographies of the crowned work gear surfaces hobbed by the standard and dual-lead rack cutters. The results reveal the superiority of the proposed novel finish hobbing method.Copyright © 2014 by ASME
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computerized tooth profile generation and analysis of characteristics of elliptical gears with circular arc teeth
Journal of Materials Processing Technology, 2004Co-Authors: Chienfa Chen, Chung-biau TsayAbstract:Abstract This study describes rack cutters with circular-arc profile teeth to generate elliptical gears which rotate about one of their foci. A mathematical model for elliptical gears with circular-arc teeth is developed according to gear theory. The influence of the design parameters, such as the number of teeth, gear module, Pressure Angle at the pitch point and the major-axis, are investigated. The effects of the circular-arc radius of the rack cutter on both the undercutting of teeth and on pointed teeth of the generated circular-arc elliptical gear are also studied. Three numerical examples are presented to elucidate the generation of gear tooth profiles using the proposed mathematical model, and to investigate the phenomena of tooth undercutting and pointed teeth.
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effects of profile shifted factor and Pressure Angle on the zk type dual lead worm gear drives
Journal of Materials Processing Technology, 2001Co-Authors: Biingwen Bair, Chung-biau TsayAbstract:Abstract In the light of a mathematical model of the ZK-type dual-lead worm gear set proposed in the authors’ recent work, this study adopts tooth contact analysis to compute the kinematic errors, instantaneous contact teeth (ICT) and average contact ratios (ACR). An elastic deformation of 3 μm is allowed while calculating ICT and ACR. In addition, increasing the ICT from three to four or from four to five reduces the root stress of the gear set due to its multiple contact teeth. Although a worm gear driven with a small Pressure Angle can increase the ICT, a worm gear with a small Pressure Angle incurs a more serious undercutting phenomena. Undercutting can also be averted by applying a positive-shifted modification of the hob cutter during the worm gear generation. Moreover, the boundary of conjugate and non-conjugate surface regions appears on the worm gear tooth surface when the worm gear has a low Pressure Angle. The non-conjugate region also influences the transmission efficiency, operational life time and noise of the worm gear drive. Furthermore, worm gear generation with a negative-shifted modification can decrease the unfavorable non-conjugate region.
Vanthe Tran - One of the best experts on this subject based on the ideXlab platform.
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manufacturing helical gears with double crowning and twist free tooth flanks using a variable Pressure Angle shaving cutter
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2019Co-Authors: Rueihung Hsu, Vanthe TranAbstract:For a parallel gear shaving process, the tooth flanks of a shaved work gear surface are longitudinally crowned using an auxiliary crowning mechanism. However, the flanks are only crowned in the lon...
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manufacturing helical gears with double crowning and twist free tooth flanks using a variable Pressure Angle shaving cutter
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2019Co-Authors: Yuren Wu, Vanthe TranAbstract:For a parallel gear shaving process, the tooth flanks of a shaved work gear surface are longitudinally crowned using an auxiliary crowning mechanism. However, the flanks are only crowned in the longitudinal direction and not in the cross-profile direction so there is a natural twist on the shaved work gear surfaces. A new shaving method for double-crowning that has no natural twist in the tooth flanks on the work gear surfaces is proposed, which uses a variable Pressure Angle shaving cutter in a parallel gear shaving process. Three numerical examples are presented to verify the merits of the proposed shaving method. The tooth flanks are crowned in both the cross-profile and the longitudinal directions, and natural twists in the shaved tooth flanks are reduced significantly.
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Transmission and load analysis for a crowned helical gear pair with twist-free tooth flanks generated by an external gear honing machine
Mechanism and Machine Theory, 2016Co-Authors: Vanthe TranAbstract:Abstract In the high speed rotational gearbox, the tooth surfaces of gears are usually crowned with twist-free tooth flanks to reduce the vibration and noise of the gear systems due to the transmission error and load variation. In this paper, a method for longitudinal crowning tooth flank of work gear surfaces is proposed by setting a crossed Angle between the honing cutter and work gear axes as a linear function of work gear's traverse feed and a variable Pressure Angle (VPA) honing cutter is also used for free twist of the crowned tooth flank in the external honing process. Besides, the transmission and load characteristics of the gear pairs using a crowned pinion with twist-free tooth flanks are need to understand. Therefore, 3-D models of the meshing gear pairs with twisted and twist-free tooth flanks are constructed and analyzed by using KISSsoft software. Three numerical examples are presented to illustrate and verify the merits of the proposed gear honing methodology as well as shed light on the transmission and load characteristics of the gear pairs with twist-free tooth flanks.
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a novel finish hobbing methodology for longitudinal crowning of a helical gear with twist free tooth flanks by using dual lead hob cutters
ASME 2014 International Mechanical Engineering Congress and Exposition, 2014Co-Authors: Vanthe Tran, Rueihung Hsu, Chung-biau TsayAbstract:In the gear finish hobbing process, to obtain a twist-free tooth flank of helical gears, a novel hobbing method for longitudinal crowning is proposed by applying a new hob’s diagonal feed motion with a dual-lead hob cutter. Wherein the hob’s diagonal feed motion is set as a second order function of hob’s traverse movement and tooth profile of hob cutter is modified in a dual-lead form with Pressure Angle changed in it’s longitudinal direction. The proposed method is verified by using two computer simulation examples to compare topographies of the crowned work gear surfaces hobbed by the standard and dual-lead rack cutters. The results reveal the superiority of the proposed novel finish hobbing method.Copyright © 2014 by ASME
Prabhu R Sekar - One of the best experts on this subject based on the ideXlab platform.
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evolution of balanced root stress and tribological properties in high contact ratio spur gear drive
Mechanism and Machine Theory, 2018Co-Authors: R Ravivarman, K Palaniradja, Prabhu R SekarAbstract:Abstract Tooth bending and surface wear are the two major causes of failure modes which occur due to inadequate bending and contact strength. In a gear drive, when the gear ratio is more than one the bending strength of the pinion and gear it is different. Consequently gear drive with an equivalent bending strength in the gear and pinion is called as a balanced gear drive. This can be attained by providing non-standard tooth thickness at the pitch circle in High Contact Ratio (HCR) spur gears. Non-standard HCR spur gear drive is one in which the tooth thickness at the pitch circle of the gear and pinion is not same. In the present study, tooth wear over the contacting surfaces for non-standard HCR spur gear drive is probed numerically through finite element analysis (FEA). In addition, the tooth load, contact stress, film thickness and sliding distance are also estimated for a balanced non-standard HCR spur gear drive. Also the effect of different gear parameters like pinion teeth number, Pressure Angle, addendum height and gear ratio on tooth wear along the line of action on non-standard HCR spur gear has been evaluated and discussed.
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enhancement of wear resistance on normal contact ratio spur gear pairs through non standard gears
Wear, 2017Co-Authors: Prabhu R Sekar, R SathishkumarAbstract:Abstract Tooth wear is considered to be one of the major causes of failure modes in gearing systems. The achieved service life of the geared unit mainly depends on the gear tooth strength and surface wear. Excessive wear is characterized by loss of tooth profile, which results in high noise and vibration, a minor loss of conjugate action and a reduction in efficiency. Hence, enhancement of gear life against wear becomes an important requirement for effective design detailing of gears. This article presents an idea to minimize the wear of the gear teeth by adopting non-standard gear. Non-standard gear is defined as one whose tooth thickness at the pitch circle is not equal to 0.5πm. In this study, the impact of the tooth thickness coefficient on tooth wear for standard and non-standard spur gears is numerically investigated. The non-standard tooth thickness in the pinion leads to enhancement of the tooth strength and leading to reduction of tooth wear. Finally, the influence of gear parameters such as gear ratio, Pressure Angle and pinion teeth number on wear depth, for non-standard pinion and gear has been investigated and the results of the parametric study are discussed.
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a mixed finite element and analytical method to predict load mechanical power loss and improved efficiency in non standard spur gear drives
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Prabhu R Sekar, Edwin V Geo, Leenus Jesu MartinAbstract:A reasonably accurate estimation of gear power loss is desirable to maximize gear performance. The load share by teeth pair, contact stress, sliding speed, elastohydrodynamic film thickness and coefficient of friction are some of the most important contributing factors which determine frictional power losses in gears. This paper presents an improvement concept to minimize the load-related power losses (sliding and rolling power losses), which will lead to an enhancement in gear efficiency by selection of non-standard gears. The tooth thickness at the pitch circle of the pinion and gear is different in non-standard gears (kpπm > 0.5 πm and kgπm < 0.5 πm), whereas it is equal in standard gears (kpπm = kgπm = 0.5 πm). In this work, the load share-based frictional power loss and the respective mechanical efficiency have been determined for comparative performance of standard and non-standard gears. Finally, the influence of various gear and drive parameters such as gear ratio, Pressure Angle pinion teeth numb...
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estimation of tooth form factor for normal contact ratio asymmetric spur gear tooth
Mechanism and Machine Theory, 2015Co-Authors: Prabhu R Sekar, G MuthuveerappanAbstract:Abstract To estimate the tooth form factor for a loaded symmetric spur gear tooth, some normalized standards like International Organization for Standardization (ISO) and American Gear Manufacturers Association (AGMA) are available. However, the tooth form factor for a loaded asymmetric spur gear tooth cannot be estimated through the available standards. An asymmetric spur gear tooth is one whose drive side Pressure Angle is different from the coast side Pressure Angle. In the present work, the standard ISO B methodology has been adapted suitably for estimating the tooth form factor and the stress correction factor in asymmetric spur gear tooth. Also, the critical root fillet parameters (critical root tooth thickness, bending moment arm and radius of curvature) and the tooth form factor for asymmetric spur gear tooth with several sets of drive side and coast side Pressure Angles are determined through an adapted ISO method and a comparative study with FEM is also carried out.
Priya Marimuthu - One of the best experts on this subject based on the ideXlab platform.
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investigation of load carrying capacity of asymmetric high contact ratio spur gear based on load sharing using direct gear design approach
Mechanism and Machine Theory, 2016Co-Authors: Priya Marimuthu, G MuthuveerappanAbstract:Abstract The Direct Gear Design® approach is one of the many gear designing methods available to improve load carrying capacity of the gear pairs. For customized gear pairs, the direct gear design approach is more advantageous over conventional design. In this paper, a parametric study is carried out for asymmetric high contact ratio spur gears based on load sharing method to determine the improvement in load carrying capacity. A finite element model for multi-pair contact is adopted to determine the non-dimensional fillet and contact stresses which quantify the load carrying capacity of the gear pairs. The results of direct designed symmetric and asymmetric high contact ratio spur gears are compared with the conventional symmetric high contact ratio spur gears. Also, the influence of gear parameters such as addendum Pressure Angle, gear ratio, teeth number and backup ratio of non-dimensional stresses is analyzed in detail. The results show significant improvement in gear pair performance for all parameters analyzed.
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design of asymmetric normal contact ratio spur gear drive through direct design to enhance the load carrying capacity
Mechanism and Machine Theory, 2016Co-Authors: Priya Marimuthu, G MuthuveerappanAbstract:Abstract Maximum fillet and contact stresses of asymmetric normal contact ratio spur gears designed by direct design method are evaluated based on the load sharing ratio, using finite element method. For a direct gear design, area of existence diagrams are developed for known input gear parameters such as number of teeth, coefficient of asymmetry, top land thickness coefficient and drive side contact ratio. A unique Ansys parametric design language code is developed to find the load sharing ratio, maximum fillet and contact stresses. The fillet stress is calculated in terms of non-dimensional stress. The influence of gear drive parameters such as drive and coast side Pressure Angles, top-land thickness coefficients, contact ratio, coefficient of asymmetry, gear ratio and teeth number on load carrying capacity has been studied extensively on non-dimensional fillet stress and maximum contact stress and compared with that of the conventionally designed gears. Through parametric study, suitable suggestions are made for the design of asymmetric gear drive for an enhanced load carrying capacity with constant contact ratio and constant drive side Pressure Angle separately.
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effect of addendum height and teeth number on asymmetric normal contact ratio spur gear based on load sharing
Universal Journal of Mechanical Engineering, 2014Co-Authors: Priya Marimuthu, G MuthuveerappanAbstract:This study explores the influence of some gear parameters such as addendum height, teeth number and module on load sharing aspect and the subsequent stress analysis. The multi pair contact model in finite element technique is used for a reasonable accurate prediction of the stresses with the application of load at high Pressure Angle side. Also, a unique Ansys parametric design language code is developed for this study. Finally the increase in addendum height results to increase the bending stress for a load at critical loading point. However the increase in teeth number and module leads to decrease in the load sharing based bending and contact stresses.