The Experts below are selected from a list of 16395 Experts worldwide ranked by ideXlab platform
Faydor L. Litvin - One of the best experts on this subject based on the ideXlab platform.
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design simulation of meshing and contact stresses for an improved worm Gear Drive
Mechanism and Machine Theory, 2007Co-Authors: Faydor L. Litvin, Kenji Yukishima, Alfonso Fuentes, Ignacio Gonzalezperez, Kenichi HayasakaAbstract:A version of a worm Gear Drive with improved bearing contact, reduced level of transmission errors and lessened sensitivity to errors of alignment is proposed. Unlike the existing approach, the hob and worm tooth surfaces are mismatched (in addition to the oversize of the hob). A localized bearing contact in longitudinal direction, with a negative (but not positive) function of transmission errors is provided in favor of increasing contact ratio. The positive features of proposed design have been confirmed by TCA (Tooth Contact Analysis) applied for unloaded and loaded Gear Drives.
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geometry and investigation of klingelnberg type worm Gear Drive
Journal of Mechanical Design, 2007Co-Authors: Faydor L. Litvin, Kenji Yukishima, Kenichi Hayasaka, Ignacio Gonzalezperez, Alfonso FuentesAbstract:The computerized design, generation, and tooth contact analysis of a Klingelnberg-type cylindrical worm Gear Drive is considered wherein localization of contact is obtained by application of an oversized hob and mismatch geometries of hob and worm of the Drive. A computerized approach for the determination of contacting surfaces and the investigation of their meshing and contact by tooth contact analysis is presented. The developed theory results in an improvement of bearing contact and reduction of sensitivity to misalignment. The theory is illustrated with numerical examples and may be applied for other types of cylindrical worm Gear Drives.
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design generation and stress analysis of face Gear Drive with helical pinion
Computer Methods in Applied Mechanics and Engineering, 2005Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Ignacio Gonzalezperez, Daniele Vecchiato, Bruce D Hansen, David Andrew BinneyAbstract:Two versions of face-Gear Drive geometry with a helical pinion are considered. One version is based on a screw involute helicoid. The second version is a new geometry developed as envelopes of two mismatched parabolic racks of the pinion and the shaper. A face-Gear Drive with a spur pinion is considered as a particular case of the developed theory. A new method of grinding or cutting of face-Gears by a worm of special shape has been developed. The following problems are considered: (i) generation of a grinding worm with surfaces free of singularities and (ii) generation of face-Gear by a shaper with surfaces free of undercutting and pointing. Tooth contact analysis and stress analysis are applied combined with investigation of tooth bearing contact on both sides. The following advantages have been achieved for the geometry proposed: (a) existence of a longitudinal bearing contact, (b) avoidance of edge contact, and (c) reduction of contact stresses. A phenomenon of asymmetry of tooth bearing contact for the driving and coast sides has been discovered. A computerized design, generation and stress analysis for the new types of face-Gear Drives have been developed.
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Gear Geometry and Applied Theory: Face-Gear Drives
Gear Geometry and Applied Theory, 2004Co-Authors: Faydor L. Litvin, Alfonso FuentesAbstract:INTRODUCTION A conventional face-Gear Drive is formed by an involute spur pinion and a conjugated face-Gear (Fig. 18.1.1). Such a Gear Drive may be applied for transformation of rotation between intersected and crossed axes. An important example of application of a face-Gear Drive with intersected axes is in the helicopter transmission (Fig. 18.1.2). The manufacturing of face-Gears by a shaper was invented by the Fellow Corporation. The basic idea of generation is based on simulation of meshing of the generating shaper with the face-Gear being generated as the meshing of the pinion of the Drive with the face-Gear. In the process of generation, the surfaces of the teeth of the shaper and the face-Gear are in line contact at every instant. However, when the shaper is exactly identical to the pinion of the face-Gear Drive, the generated face-Gear Drive becomes sensitive to misalignment. This causes an undesirable shift of the bearing contact and even separation of the surfaces. Therefore, it is necessary to provide an instantaneous point contact between the tooth surfaces of the pinion and the face-Gear instead of a line contact. Then, the bearing contact will be localized and the face-Gear Drive will be less sensitive to misalignment. Point contact between the pinion and face-Gear tooth surfaces is provided by application of a shaper of number of teeth N s > N p where N p is the number of teeth of the pinion of the Drive (see Section 18.4).
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new version of novikov wildhaber helical Gears computerized design simulation of meshing and stress analysis
Computer Methods in Applied Mechanics and Engineering, 2002Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Ignacio Gonzalezperez, Luca CarnevaliAbstract:Abstract A new version of Novikov–Wildhaber Gear Drive is considered. The contents of the paper cover design, generation, tooth contact analysis (TCA), and stress analysis of a new type of Novikov–Wildhaber helical Gear Drive. The great advantages of the developed Gear Drive in comparison with the previous ones are (i) reduction of noise and vibration caused by errors of alignment, (ii) the possibility of grinding and application of hardened materials, and (iii) reduction of stresses. These achievements are obtained by application of (i) new geometry (based on application of parabolic rack-cutters), (ii) double-crowning of pinion, and (iii) parabolic type of transmission errors. The manufacture of Gears is based on application of grinding or cutting disks, and grinding or cutting worms. The advantages of the developed Gear Drive have been confirmed by simulation of meshing and contact, stress analysis, and investigation of formation of bearing contact. Computer programs that cover computerized design, TCA, and automatic development of finite element models of new version of Novikov–Wildhaber Gear Drives have been developed. A general purpose finite element analysis computer program has been used for stress analysis and investigation of formation of bearing contact. Helical Gears of new geometry can be applied in high-speed transmissions. The developed theory is illustrated with numerical examples.
Massimiliano Donno - One of the best experts on this subject based on the ideXlab platform.
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computer program in visual basic language for simulation of meshing and contact of Gear Drives and its application for design of worm Gear Drive
Computer Methods in Applied Mechanics and Engineering, 2000Co-Authors: John Argyris, Massimiliano Donno, Faydor L. LitvinAbstract:The authors propose: (i) enhanced computer program for simulation of meshing and contact of Gear Drives; (ii) application of computer program for analysis of worm Gear Drive; and (iii) advanced design of worm Gear Drive with reduced transmission errors and favorable bearing contact. The output of Tooth Contact Analysis (TCA) program are: function of transmission errors, path of contact and bearing contact. The program is written in Visual Basic language and enables to combine numerical computation and graphical illustration. The improved design of worm Gear Drive is based on application of an oversized hob and modified worm generated by varied plunging of the generating tool. It is discovered that worm generation without tool plunging may cause positive transmission errors, unacceptable for favorable conditions of force transmission. Positive transmission errors are the herald of possible surface interference. A predesigned parabolic function of transmission errors is provided in order to absorb transmission errors caused by errors of alignment and reduce the level of vibrations, especially in the case of application of multi-thread worms. The investigation is accomplished for a worm-Gear Drive with the Klingelnberg type of the worm that is ground by a circular cone, but the proposed approach may be applied for other types of worm Gear Drives with cylindrical worms.
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Integrated computer program for simulation of meshing and contact of Gear Drives
Computer Methods in Applied Mechanics and Engineering, 2000Co-Authors: Faydor L. Litvin, Massimiliano Donno, Aoyong Peng, A. Vorontsov, Robert F HandschuhAbstract:The authors propose an integrated Tooth Contact Analysis (TCA) computer program for simulation of meshing and contact of Gear Drives that enables to determine transmission errors and shift of bearing contact for misaligned Gear Drives. The developed computer program combines numerical solutions for the problems above and their graphical interpretation. The program is applicable for various Gear Drives but needs derivation of tooth surface equations specified for the considered Gear Drive. The computer program represents a set of integrated operations such as the development of required algorithms, storing in database, copying, deleting, printing, design correction from the database, etc. The proposed computer program is based on application of the Java programming language. Examples of application for a spiral bevel Gear Drive and a worm Gear Drive are provided.
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computerized design and generation of modified spiroid worm Gear Drive with low transmission errors and stabilized bearing contact
Computer Methods in Applied Mechanics and Engineering, 1998Co-Authors: Faydor L. Litvin, Massimiliano DonnoAbstract:The authors propose a modified geometry of a spiroid worm-Gear Drive with localized bearing contact, reduced level of transmission errors and a parabolic shape of function of transmission errors. Computerized design of the worm-Gear Drive that enables to discover and avoid singularities of the generated worm face-Gear surface and pointing of teeth is developed. Simulation of meshing by TCA (Tooth Contact Analysis) computer program is developed to determine the shift of bearing contact and transmission errors caused by misalignment. Numerical examples that illustrate the developed theory are provided.
Alfonso Fuentes - One of the best experts on this subject based on the ideXlab platform.
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design simulation of meshing and contact stresses for an improved worm Gear Drive
Mechanism and Machine Theory, 2007Co-Authors: Faydor L. Litvin, Kenji Yukishima, Alfonso Fuentes, Ignacio Gonzalezperez, Kenichi HayasakaAbstract:A version of a worm Gear Drive with improved bearing contact, reduced level of transmission errors and lessened sensitivity to errors of alignment is proposed. Unlike the existing approach, the hob and worm tooth surfaces are mismatched (in addition to the oversize of the hob). A localized bearing contact in longitudinal direction, with a negative (but not positive) function of transmission errors is provided in favor of increasing contact ratio. The positive features of proposed design have been confirmed by TCA (Tooth Contact Analysis) applied for unloaded and loaded Gear Drives.
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geometry and investigation of klingelnberg type worm Gear Drive
Journal of Mechanical Design, 2007Co-Authors: Faydor L. Litvin, Kenji Yukishima, Kenichi Hayasaka, Ignacio Gonzalezperez, Alfonso FuentesAbstract:The computerized design, generation, and tooth contact analysis of a Klingelnberg-type cylindrical worm Gear Drive is considered wherein localization of contact is obtained by application of an oversized hob and mismatch geometries of hob and worm of the Drive. A computerized approach for the determination of contacting surfaces and the investigation of their meshing and contact by tooth contact analysis is presented. The developed theory results in an improvement of bearing contact and reduction of sensitivity to misalignment. The theory is illustrated with numerical examples and may be applied for other types of cylindrical worm Gear Drives.
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design generation and stress analysis of face Gear Drive with helical pinion
Computer Methods in Applied Mechanics and Engineering, 2005Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Ignacio Gonzalezperez, Daniele Vecchiato, Bruce D Hansen, David Andrew BinneyAbstract:Two versions of face-Gear Drive geometry with a helical pinion are considered. One version is based on a screw involute helicoid. The second version is a new geometry developed as envelopes of two mismatched parabolic racks of the pinion and the shaper. A face-Gear Drive with a spur pinion is considered as a particular case of the developed theory. A new method of grinding or cutting of face-Gears by a worm of special shape has been developed. The following problems are considered: (i) generation of a grinding worm with surfaces free of singularities and (ii) generation of face-Gear by a shaper with surfaces free of undercutting and pointing. Tooth contact analysis and stress analysis are applied combined with investigation of tooth bearing contact on both sides. The following advantages have been achieved for the geometry proposed: (a) existence of a longitudinal bearing contact, (b) avoidance of edge contact, and (c) reduction of contact stresses. A phenomenon of asymmetry of tooth bearing contact for the driving and coast sides has been discovered. A computerized design, generation and stress analysis for the new types of face-Gear Drives have been developed.
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Gear Geometry and Applied Theory: Face-Gear Drives
Gear Geometry and Applied Theory, 2004Co-Authors: Faydor L. Litvin, Alfonso FuentesAbstract:INTRODUCTION A conventional face-Gear Drive is formed by an involute spur pinion and a conjugated face-Gear (Fig. 18.1.1). Such a Gear Drive may be applied for transformation of rotation between intersected and crossed axes. An important example of application of a face-Gear Drive with intersected axes is in the helicopter transmission (Fig. 18.1.2). The manufacturing of face-Gears by a shaper was invented by the Fellow Corporation. The basic idea of generation is based on simulation of meshing of the generating shaper with the face-Gear being generated as the meshing of the pinion of the Drive with the face-Gear. In the process of generation, the surfaces of the teeth of the shaper and the face-Gear are in line contact at every instant. However, when the shaper is exactly identical to the pinion of the face-Gear Drive, the generated face-Gear Drive becomes sensitive to misalignment. This causes an undesirable shift of the bearing contact and even separation of the surfaces. Therefore, it is necessary to provide an instantaneous point contact between the tooth surfaces of the pinion and the face-Gear instead of a line contact. Then, the bearing contact will be localized and the face-Gear Drive will be less sensitive to misalignment. Point contact between the pinion and face-Gear tooth surfaces is provided by application of a shaper of number of teeth N s > N p where N p is the number of teeth of the pinion of the Drive (see Section 18.4).
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new version of novikov wildhaber helical Gears computerized design simulation of meshing and stress analysis
Computer Methods in Applied Mechanics and Engineering, 2002Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Ignacio Gonzalezperez, Luca CarnevaliAbstract:Abstract A new version of Novikov–Wildhaber Gear Drive is considered. The contents of the paper cover design, generation, tooth contact analysis (TCA), and stress analysis of a new type of Novikov–Wildhaber helical Gear Drive. The great advantages of the developed Gear Drive in comparison with the previous ones are (i) reduction of noise and vibration caused by errors of alignment, (ii) the possibility of grinding and application of hardened materials, and (iii) reduction of stresses. These achievements are obtained by application of (i) new geometry (based on application of parabolic rack-cutters), (ii) double-crowning of pinion, and (iii) parabolic type of transmission errors. The manufacture of Gears is based on application of grinding or cutting disks, and grinding or cutting worms. The advantages of the developed Gear Drive have been confirmed by simulation of meshing and contact, stress analysis, and investigation of formation of bearing contact. Computer programs that cover computerized design, TCA, and automatic development of finite element models of new version of Novikov–Wildhaber Gear Drives have been developed. A general purpose finite element analysis computer program has been used for stress analysis and investigation of formation of bearing contact. Helical Gears of new geometry can be applied in high-speed transmissions. The developed theory is illustrated with numerical examples.
Robert F Handschuh - One of the best experts on this subject based on the ideXlab platform.
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Offset Compound Gear Drive
2010Co-Authors: Mark A. Stevens, Robert F Handschuh, David G. LewickiAbstract:The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound Gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input Gear and a larger internal tooth output Gear. This unique geometry and offset axis permits the compound Gear to mesh with the smaller diameter input Gear and the larger diameter output Gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction Gear set consisting of fewer Gears and bearings than a conventional planetary Gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input Gear to 7.50 PD (internal tooth) intermediate Gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate Gear to a 10.00 PD output Gear (0.750 reduction mesh). Note that it is not required that the intermediate Gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output Gear, power is transmitted through a hollow Drive shaft, which, in turn, Drives a sprag during which time the main clutch is disengaged.
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face Gear Drive with spur involute pinion geometry generation by a worm stress analysis
Computer Methods in Applied Mechanics and Engineering, 2002Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Claudio Zanzi, Matteo Pontiggia, Robert F HandschuhAbstract:A face-Gear Drive with a spur involute pinion is considered. The generation of the face Gear is based on application of a grinding or cutting worm whereas the conventional method of generation is based on application of an involute shaper. The authors have developed an analytical approach for determination of: (i) the worm thread surface, (ii) avoidance of singularities of the worm thread surface, (iii) dressing of the worm, and (iv) determination of stresses of the face-Gear Drive. A computer program is developed for simulation of meshing and contact of the pinion and face Gear. Correction of machine-tool settings is proposed for reduction of the shift of the bearing contact caused by misalignment. An automatic development of the model of five contacting teeth has been proposed for stress analysis. Numerical examples for illustration of the developed theory are provided.
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Integrated computer program for simulation of meshing and contact of Gear Drives
Computer Methods in Applied Mechanics and Engineering, 2000Co-Authors: Faydor L. Litvin, Massimiliano Donno, Aoyong Peng, A. Vorontsov, Robert F HandschuhAbstract:The authors propose an integrated Tooth Contact Analysis (TCA) computer program for simulation of meshing and contact of Gear Drives that enables to determine transmission errors and shift of bearing contact for misaligned Gear Drives. The developed computer program combines numerical solutions for the problems above and their graphical interpretation. The program is applicable for various Gear Drives but needs derivation of tooth surface equations specified for the considered Gear Drive. The computer program represents a set of integrated operations such as the development of required algorithms, storing in database, copying, deleting, printing, design correction from the database, etc. The proposed computer program is based on application of the Java programming language. Examples of application for a spiral bevel Gear Drive and a worm Gear Drive are provided.
Ignacio Gonzalezperez - One of the best experts on this subject based on the ideXlab platform.
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design simulation of meshing and contact stresses for an improved worm Gear Drive
Mechanism and Machine Theory, 2007Co-Authors: Faydor L. Litvin, Kenji Yukishima, Alfonso Fuentes, Ignacio Gonzalezperez, Kenichi HayasakaAbstract:A version of a worm Gear Drive with improved bearing contact, reduced level of transmission errors and lessened sensitivity to errors of alignment is proposed. Unlike the existing approach, the hob and worm tooth surfaces are mismatched (in addition to the oversize of the hob). A localized bearing contact in longitudinal direction, with a negative (but not positive) function of transmission errors is provided in favor of increasing contact ratio. The positive features of proposed design have been confirmed by TCA (Tooth Contact Analysis) applied for unloaded and loaded Gear Drives.
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geometry and investigation of klingelnberg type worm Gear Drive
Journal of Mechanical Design, 2007Co-Authors: Faydor L. Litvin, Kenji Yukishima, Kenichi Hayasaka, Ignacio Gonzalezperez, Alfonso FuentesAbstract:The computerized design, generation, and tooth contact analysis of a Klingelnberg-type cylindrical worm Gear Drive is considered wherein localization of contact is obtained by application of an oversized hob and mismatch geometries of hob and worm of the Drive. A computerized approach for the determination of contacting surfaces and the investigation of their meshing and contact by tooth contact analysis is presented. The developed theory results in an improvement of bearing contact and reduction of sensitivity to misalignment. The theory is illustrated with numerical examples and may be applied for other types of cylindrical worm Gear Drives.
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design generation and stress analysis of face Gear Drive with helical pinion
Computer Methods in Applied Mechanics and Engineering, 2005Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Ignacio Gonzalezperez, Daniele Vecchiato, Bruce D Hansen, David Andrew BinneyAbstract:Two versions of face-Gear Drive geometry with a helical pinion are considered. One version is based on a screw involute helicoid. The second version is a new geometry developed as envelopes of two mismatched parabolic racks of the pinion and the shaper. A face-Gear Drive with a spur pinion is considered as a particular case of the developed theory. A new method of grinding or cutting of face-Gears by a worm of special shape has been developed. The following problems are considered: (i) generation of a grinding worm with surfaces free of singularities and (ii) generation of face-Gear by a shaper with surfaces free of undercutting and pointing. Tooth contact analysis and stress analysis are applied combined with investigation of tooth bearing contact on both sides. The following advantages have been achieved for the geometry proposed: (a) existence of a longitudinal bearing contact, (b) avoidance of edge contact, and (c) reduction of contact stresses. A phenomenon of asymmetry of tooth bearing contact for the driving and coast sides has been discovered. A computerized design, generation and stress analysis for the new types of face-Gear Drives have been developed.
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new version of novikov wildhaber helical Gears computerized design simulation of meshing and stress analysis
Computer Methods in Applied Mechanics and Engineering, 2002Co-Authors: Faydor L. Litvin, Alfonso Fuentes, Ignacio Gonzalezperez, Luca CarnevaliAbstract:Abstract A new version of Novikov–Wildhaber Gear Drive is considered. The contents of the paper cover design, generation, tooth contact analysis (TCA), and stress analysis of a new type of Novikov–Wildhaber helical Gear Drive. The great advantages of the developed Gear Drive in comparison with the previous ones are (i) reduction of noise and vibration caused by errors of alignment, (ii) the possibility of grinding and application of hardened materials, and (iii) reduction of stresses. These achievements are obtained by application of (i) new geometry (based on application of parabolic rack-cutters), (ii) double-crowning of pinion, and (iii) parabolic type of transmission errors. The manufacture of Gears is based on application of grinding or cutting disks, and grinding or cutting worms. The advantages of the developed Gear Drive have been confirmed by simulation of meshing and contact, stress analysis, and investigation of formation of bearing contact. Computer programs that cover computerized design, TCA, and automatic development of finite element models of new version of Novikov–Wildhaber Gear Drives have been developed. A general purpose finite element analysis computer program has been used for stress analysis and investigation of formation of bearing contact. Helical Gears of new geometry can be applied in high-speed transmissions. The developed theory is illustrated with numerical examples.
