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R Gnanamoorthy - One of the best experts on this subject based on the ideXlab platform.
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Transmission efficiency of polyamide nanocomposite Spur Gears
Materials & Design, 2012Co-Authors: S Kirupasankar, C Gurunathan, R GnanamoorthyAbstract:Abstract Gears made of polymer and its composites find increasing application due to their superior properties. This paper reports the transmission efficiency of pristine polyamide 6 (PA6) and clay incorporated polyamide nanocomposite (PNC) Spur Gears. Numerical studies were conducted to predict the frictional and hysteresis power loss. A power absorption type gear test rig, developed in-house, was used to determine the power loss during transmission. The effect of applied torque on the transmission efficiency of PA6 and PNC Spur Gears are reported. Addition of nanoclay particles improves the stiffness and suppresses the viscoelastic nature of polyamide 6. The increase in gear tooth temperature due to hysteresis and friction, significantly affects the tooth shape, and thereby, the gear performance. The enhancement in mechanical properties of polyamide nanocomposite Gears results in higher power transmission efficiency compared to pristine polyamide gear.
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effect of rotational speed on the performance of unreinforced and glass fiber reinforced nylon 6 Spur Gears
Materials & Design, 2007Co-Authors: S. Senthilvelan, R GnanamoorthyAbstract:Polymer Gears used in power and motion transmission work under different loads and speeds. Mechanical properties of the polymers are severely influenced by the loading rate compared with the metals. The gear rotational speed decides the loading frequency of the polymer gear tooth, which influences the temperature generated and thereby the strength of the material. Performance of polymer base Gears at different gear rotational speeds is reported in this paper. Injection molded unreinforced Nylon 6 and 20% short glass fiber reinforced Nylon 6 Spur Gears were tested at various speeds and torque levels in a power absorption type gear test rig. Gear rotational speed affects the performance of Gears made of both the materials at high running speeds and high test torques and not in low speeds and torque levels. On-line measurement of test gear surface temperature and failure analysis was done to understand the failure mechanisms. At all the investigated gear speeds, glass fiber reinforced Nylon 6 Gears shows superior performance over unreinforced Nylon 6 Gears due its superior mechanical strength and resistance to thermal deformation.
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damping characteristics of unreinforced glass and carbon fiber reinforced nylon 6 6 Spur Gears
Polymer Testing, 2006Co-Authors: S. Senthilvelan, R GnanamoorthyAbstract:Polymer based Gears replace metal Gears in many light duty power and/or motion transmission applications due to their noiseless operation even under unlubricated conditions. Visco elastic behaviour of the polymer, which is mainly responsible for the sound absorption, is altered by the addition of short fibers. Addition of high modulus fibers to the base polymer matrix reduces the damping characteristics of the composite. Material damping affects the hysteresis heating as well as the ability to absorb vibration during service. Dynamic mechanical analysis carried out on unreinforced Nylon 6/6, 20% short glass and 20% carbon fiber reinforced Nylon 6/6 gear materials indicates the reduction of damping factor due to the incorporation of fibers. Injection molded Spur Gears made of unreinforced and reinforced materials were tested for durability in a power absorption type gear test rig. Surface temperature of the test Gears and noise generated near the gear mesh region were continuously measured and monitored using a personal computer based data acquisition system. Test results indicate that the reinforced Gears generate more gear mesh noise than unreinforced Gears.
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Damage Mechanisms in Injection Molded Unreinforced, Glass and Carbon Reinforced Nylon 66 Spur Gears
Applied Composite Materials, 2004Co-Authors: S. Senthilvelan, R GnanamoorthyAbstract:Application of short fiber reinforced thermoplastic materials are limited to functionally less important components due to heterogeneous characteristics of material and incomplete understanding of failure mechanisms involved. Reinforcement not only affects mechanical and electrical properties but also the failure mechanisms. Gears used in power/motion transmission may fail in many ways. This paper discusses the various types of failures exhibited by unreinforced and fiber reinforced Nylon 66 Gears. Injection molded unreinforced, glass reinforced and carbon reinforced Nylon 66 Spur Gears were tested in a power absorption type gear test rig. Failed Gears were observed under optical and scanning electron microscope to understand the damage mechanism. Different types of failures such as gear tooth wear, cracking at the tooth surface, tooth root cracking and severe tooth shape deformation were observed. Material compositions and applied torque decides the type of failure mechanism. Low interfacial strength between fibers and matrix in the reinforced Gears causes fiber pullout. Reinforced Gears exhibited longer life compared with the unreinforced Gears due to superior mechanical strength and thermal resistance.
Bangchun Wen - One of the best experts on this subject based on the ideXlab platform.
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calculation of mesh stiffness of Spur Gears considering complex foundation types and crack propagation paths
Mechanical Systems and Signal Processing, 2019Co-Authors: Kangkang Chen, Yifan Huangfu, Bangchun WenAbstract:Abstract Based on the finite element theory and the loaded tooth contact analysis, an analytical-finite-element model considering the complex foundation types and the crack propagation paths is proposed to calculate the mesh stiffness of Spur Gears. The complex gear foundation types (including web foundation and slots foundation) and the crack propagation paths (including tooth fracture and rim fracture) are considered in the proposed method, and the effects of various foundation types, crack propagation paths and crack lengths on the mesh stiffness are analyzed. In order to verify the proposed method, the simulated crack paths are confirmed by those derived from the experimental and the extended finite element methods, and the mesh stiffness obtained from the proposed method is validated by that of the potential energy method and the three-dimensional finite element method. Compared with the potential energy method, the proposed model can be used to calculate the mesh stiffness of Spur Gears with different gear foundation types and real crack propagation paths. Meanwhile, the proposed method has higher computational efficiency compared with the finite element method (e.g., the finite element method takes about 3.5 h for a mesh cycle and the proposed method costs 25 s). The results indicate that the web thickness has greater influence on the mesh stiffness of Spur Gears than the rim thickness. The results show that two crack types, namely the tooth fracture and rim fracture, have more obvious influence on the mesh stiffness of single-tooth contact zone relative to that of the double-tooth contact zone.
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investigation on meshing and dynamic characteristics of Spur Gears with tip relief under wear fault
Science China-technological Sciences, 2019Co-Authors: Yifan Huangfu, Kangkang Chen, Baishun Zhao, Bangchun WenAbstract:Combining the loaded tooth contact analysis (LTCA) method and the gear dynamic model, a wear prediction model for Spur Gears with tip relief is established. The simulated wear depth is verified by the experimental results in a published reference. Based on the wear profile, the mesh stiffness and the tooth root stress obtained from the proposed model are compared with those obtained from the finite element model. Relative to the finite element method, the proposed method can greatly reduce the computation time. The effects of the tip relief and surface wear on the meshing and the dynamic characteristics are discussed. The tip relief can greatly decelerate the surface wear. Appropriate tip relief and slight wear can decrease the tooth interference and reduce the system vibration. Furthermore, the effects of the rotational speed on the wear depth are also studied and it is found that the quasi-static model is applicable to wear prediction when the rotational speed is away from the harmonic resonance peak.
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time varying mesh stiffness calculation of Spur Gears with spalling defect
Engineering Failure Analysis, 2016Co-Authors: Mengjiao Feng, Ranjiao Feng, Bangchun WenAbstract:Abstract Considering the effects of extended tooth contact (ETC), revised fillet-foundation stiffness under double-tooth engagement region, nonlinear contact stiffness and tooth spalling defect, an analytical model for time-varying mesh stiffness (TVMS) calculation of Spur Gears is established. In addition, the analytical model is also verified by comparing the TVMS under different spalling widths, lengths and locations with that obtained from finite element method. The results show that gear mesh stiffness decreases sharply with the increase of spalling width, especially during the single-tooth engagement; the spalling length only has an effect on the beginning and ending of gear mesh stiffness reduction; the spalling location can affect the range of gear mesh stiffness reduction, and the range will reduce when the spalling location is close to the addendum. This study can provide a theoretical basis for spalling defect diagnosis.
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improved time varying mesh stiffness model of cracked Spur Gears
Engineering Failure Analysis, 2015Co-Authors: Xu Pang, Ranjiao Feng, Jin Zeng, Bangchun WenAbstract:Abstract Based on our previous work (Ma et al., 2014, Engineering Failure Analysis , 44, 179–194), this paper presents an improved analytical model (IAM) for the time-varying mesh stiffness (TVMS) calculation of cracked Spur Gears. In the improved analytical model, the calculation error of TVMS under double-tooth engagement due to repeatedly considering the stiffness of the fillet-foundation is revised, and the effects of reduction of fillet-foundation stiffness of cracked Gears and extended tooth contact (ETC) are also considered, which have a great influence on TVMS, especially under the condition of large torques and crack levels. Moreover, the comparisons among the IAM, traditional analytical model (TAM) and finite element (FE) model are also carried out under different torques and crack depths. IAM is also verified by comparing TVMS and vibration responses obtained by FE model, which can be considered as a gauge to evaluate the calculation error. The results show that the maximum error of IAM is about 12.04%, however, that of TAM can be up to 32.73%.
S. Senthilvelan - One of the best experts on this subject based on the ideXlab platform.
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surface durability of injection moulded carbon nanotube polypropylene Spur Gears
Proceedings of the Institution of Mechanical Engineers Part L: Journal of Materials Design and Applications, 2018Co-Authors: Johnney A Mertens, S. SenthilvelanAbstract:Short fibre reinforced thermoplastics are being considered for light- and medium-duty engineering applications because of their improved mechanical strength combined with cost-effective advantages. In recent years, the carbon nanotube reinforced thermoplastics are being preferred over the short fibre reinforced thermoplastics because of the absence of directional shrinkage characteristics, directional mechanical and tribological properties. In this work, 1 wt% carbon nanotube–polypropylene material was injection-moulded to Spur Gears and evaluated for the durability using in-house developed power absorption gear test rig. During testing, the net surface temperature of the test Gears and in-line torque available at the driver and driven shafts were continuously measured. The measured torque was used to evaluate the transmission efficiency of the test-steel gear pair. The measured net surface temperature was correlated with the gear failure mode. Test Gears were run up to failure or up to 8.6 × 105 cycles, ...
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effect of rotational speed on the performance of unreinforced and glass fiber reinforced nylon 6 Spur Gears
Materials & Design, 2007Co-Authors: S. Senthilvelan, R GnanamoorthyAbstract:Polymer Gears used in power and motion transmission work under different loads and speeds. Mechanical properties of the polymers are severely influenced by the loading rate compared with the metals. The gear rotational speed decides the loading frequency of the polymer gear tooth, which influences the temperature generated and thereby the strength of the material. Performance of polymer base Gears at different gear rotational speeds is reported in this paper. Injection molded unreinforced Nylon 6 and 20% short glass fiber reinforced Nylon 6 Spur Gears were tested at various speeds and torque levels in a power absorption type gear test rig. Gear rotational speed affects the performance of Gears made of both the materials at high running speeds and high test torques and not in low speeds and torque levels. On-line measurement of test gear surface temperature and failure analysis was done to understand the failure mechanisms. At all the investigated gear speeds, glass fiber reinforced Nylon 6 Gears shows superior performance over unreinforced Nylon 6 Gears due its superior mechanical strength and resistance to thermal deformation.
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damping characteristics of unreinforced glass and carbon fiber reinforced nylon 6 6 Spur Gears
Polymer Testing, 2006Co-Authors: S. Senthilvelan, R GnanamoorthyAbstract:Polymer based Gears replace metal Gears in many light duty power and/or motion transmission applications due to their noiseless operation even under unlubricated conditions. Visco elastic behaviour of the polymer, which is mainly responsible for the sound absorption, is altered by the addition of short fibers. Addition of high modulus fibers to the base polymer matrix reduces the damping characteristics of the composite. Material damping affects the hysteresis heating as well as the ability to absorb vibration during service. Dynamic mechanical analysis carried out on unreinforced Nylon 6/6, 20% short glass and 20% carbon fiber reinforced Nylon 6/6 gear materials indicates the reduction of damping factor due to the incorporation of fibers. Injection molded Spur Gears made of unreinforced and reinforced materials were tested for durability in a power absorption type gear test rig. Surface temperature of the test Gears and noise generated near the gear mesh region were continuously measured and monitored using a personal computer based data acquisition system. Test results indicate that the reinforced Gears generate more gear mesh noise than unreinforced Gears.
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Damage Mechanisms in Injection Molded Unreinforced, Glass and Carbon Reinforced Nylon 66 Spur Gears
Applied Composite Materials, 2004Co-Authors: S. Senthilvelan, R GnanamoorthyAbstract:Application of short fiber reinforced thermoplastic materials are limited to functionally less important components due to heterogeneous characteristics of material and incomplete understanding of failure mechanisms involved. Reinforcement not only affects mechanical and electrical properties but also the failure mechanisms. Gears used in power/motion transmission may fail in many ways. This paper discusses the various types of failures exhibited by unreinforced and fiber reinforced Nylon 66 Gears. Injection molded unreinforced, glass reinforced and carbon reinforced Nylon 66 Spur Gears were tested in a power absorption type gear test rig. Failed Gears were observed under optical and scanning electron microscope to understand the damage mechanism. Different types of failures such as gear tooth wear, cracking at the tooth surface, tooth root cracking and severe tooth shape deformation were observed. Material compositions and applied torque decides the type of failure mechanism. Low interfacial strength between fibers and matrix in the reinforced Gears causes fiber pullout. Reinforced Gears exhibited longer life compared with the unreinforced Gears due to superior mechanical strength and thermal resistance.
Hua Jiang - One of the best experts on this subject based on the ideXlab platform.
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molecular Spur Gears based on a switchable quinquepyridine foldamer acting as a stator
Journal of Organic Chemistry, 2017Co-Authors: Fu Huang, Guangxia Wang, Ying Wang, Xuebo Chen, Yanke Che, Hua JiangAbstract:Two triptycene rotators have been covalently linked to the backbone of a quinquepyridine (QPY) foldamer at the second and fourth pyridine rings, respectively, to form molecular Spur Gears. The studies revealed that a QPY foldamer as a stator can reversibly control the intermeshed and demeshed states of molecular Spur Gears due to the linear-to-helical conformational switching triggered by complexation/decomplexation.
Jose I Pedrero - One of the best experts on this subject based on the ideXlab platform.
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On the evaluation of the meshing stiffness of external Spur Gears
'EDP Sciences', 2020Co-Authors: Miguel Pleguezuelos, Miryam B. Sánchez, Jose I PedreroAbstract:A comparison among different approaches of the meshing stiffness of Spur Gears has been carried out. The influence of each one on the load sharing, and subsequently on the determinant tooth-root and contact stresses, has also been studied. Equations for the evolution of the meshing stiffness along the path of contact according to all these formulations are also provided
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Study of the tooth contact for high contact ratio Spur Gears with long tip relief
MATEC Web of Conferences, 2019Co-Authors: Jose I Pedrero, Miguel Pleguezuelos, Miryam B. SánchezAbstract:Profile modifications are commonly used to avoid shocks between meshing gear teeth produced by the delay of the driven gear, and the subsequent sooner start of contact, due to the teeth deflections. A suitable tip relief at the driven tooth shifts the start of contact to the proper location at the theoretical inner point of contact. The shape of the relief governs the loading curve of the tooth pair, while the length of relief determines the intervals in which this actual loading curve differs from the theoretical one of unmodified teeth. As at least one tooth pair should be in contact at the unmodified involute profile interval, the length of modification should be smaller than the length of the intervals of two pair tooth contact; otherwise, a shock at the end of contact of the previous pair is unavoidable. However this problem does not occur for high contact ratio Spur Gears, in which at least two couples of teeth are in contact at any moment. In this work, a study on the load sharing and the quasi-static transmission error for high contact ratio Spur Gears with long profile modification has been performed, and a model for the tooth contact has been developed.
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approximate equations for the meshing stiffness and the load sharing ratio of Spur Gears including hertzian effects
Mechanism and Machine Theory, 2017Co-Authors: Miryam B. Sánchez, Miguel Pleguezuelos, Jose I PedreroAbstract:Abstract In this paper, the meshing stiffness of Spur gear pairs, considering both global tooth deflections and local contact deflections, is evaluated at any point of the path of contact and approximated by an analytical, simple function. With this function, the load sharing ratio is calculated and compared with previous results obtained from the hypothesis of minimum elastic potential energy (MEPE model), considering the tooth deflections, but neglecting the hertzian deflections. Critical bending and contact stresses from both models are also compared both for standard and high contact ratio Spur Gears.
