Novel profile modification methodology for moulded face-gear drives

Author(s):  
M-F Tsay ◽  
Z-H Fong

Owing to modern forging and moulding technology, not only are increasing numbers of face gears being made by die, but the quality of the moulded face gear is comparable to that for gears made by a shaping process. The contact pattern of the face gear drive is designed in a manner similar to that for the bevel gear, with a localized bearing that reduces the sensitivity of axes misalignment. This paper proposes a novel profile modification methodology for the moulded face-gear drive that enhances the controllability of the contact pattern and transmission characteristics. Specifically, a skew double crowning is applied on the tooth surface of a face gear whose pinion is a standard involute helical gear. The proposed method - for which computer-aided design software for the tooth surface geometry was developed - can also separately control the bias angle and bearing ratio of the contact pattern, as well as the amplitude of transmission error. Overall, as shown here using several numerical examples, the proposed modified methodology is highly flexible.

2011 ◽  
Vol 86 ◽  
pp. 39-42
Author(s):  
Xiang Wei Cai ◽  
Zong De Fang ◽  
Jin Zhan Su

The generating of face gear with arcuate tooth has been proposed in this paper, and the meshing characteristics are investigated. Based on the concept of imaginary gear cutter, tooth surface equation has been derived, flank modification has also been considered. The transmission errors and bearing contacts of the face gear drive with arcuate tooth under different assembly conditions are investigated by applying the tooth contact analysis. The numerical results reveal that the bearing contacts are not sensitive to the errors of misalignments, and a more favorable type parabolic function of transmission errors with better symmetry and reduced amplitude may be obtained according to the modification of the face gear.


2010 ◽  
Vol 44-47 ◽  
pp. 1948-1951
Author(s):  
Ning Zhao ◽  
Hui Guo

The coordinate systems for cutting face gears and for meshing of face gear drive with involute cylindrical pinion. The tooth surface equation of face gear with machining errors is deviated, such as change of shaft angle, change of shortest distance between face gear and cutter tool axes, helix angle of cutter tool. Tooth contact analysis applied in the paper considered with the alignment error of the driving system. The tooth contact path and the transmission error of the face gear drive were simulated through the tooth contact analysis for different alignment errors and machining errors. The simulation results indicate that all of the alignment errors and machining error don’t cause transmission error except helix angle error of the cutting tool. The errors will bring the shift of the contact path on gear teeth. The shift of bearing contact can be reduced by combination of different errors of alignment or machining.


2010 ◽  
Vol 29-32 ◽  
pp. 1711-1716
Author(s):  
Shu Yan Zhang ◽  
Hui Guo

A double direction modification with a grinding worm is applied on tooth surface of face gear drive. The surface equations of the rack cutter, shaper and grinding worm are derived respectively. Loaded tooth contact analysis (LTCA) with finite element method (FEM) is performed to investigate the meshing performance of face gear drive before modification and after modification. The modification by a grinding worm can obviously reduce the sensitivity of face gear drive to misalignment; the bending stress and the contact stress are reduced with avoiding edge contact; the load transmission error is reduced. This method can obtain a more stable bearing contact in contrast to the method by increasing tooth number of shaper, and the modification magnitude can be controlled freely. The investigation is illustrated with numerical examples.


2014 ◽  
Vol 8 (2) ◽  
pp. 45-50
Author(s):  
Illés Dudás ◽  
Sándor Bodzás

Based on the general mathematical model of Illés Dudás which is appropriate for mathematical modelling of production technology methods we have worked out a model for resharpening analysis of conical hob. After the hob resharpening using numerical calculations the determination of the tooth surface of face gear by cutting edges is necessary for the analysis. Based on this methods we could calculate the permissible critical angle of the hob and the profiles of the hob and the face gear in axial section. The permissible critical angle of the hob is the critical angle the hob cutting edge of which manufactured face gear profile is situated in the permissible profile error tolerance. We have worked out a new geometric conical worm gear drive that is the conical worm gear drive having arched profile. Using this mathematical model we have done resharpening analysis for the hob having arched profile and determined the permissible critical angle.


Author(s):  
Chao Lin ◽  
Hai Gong ◽  
Ning Nie ◽  
Qinlong Zen ◽  
Lei Zhang

As the current research of face gear drive cannot realize fluctuating gear ratio, a design method of orthogonal fluctuating gear ratio face gear drive is proposed. The mathematical model of orthogonal fluctuating gear ratio face gear drive is found based on the space engagement theory. The equation of the pitch curve, addendum curve and dedendum curve of face gear are derived. The design method of tooth surface of the face gear is available based on the envelope method. The conversion relationship of enveloping coordinate systems is obtained during the enveloping process of orthogonal fluctuating gear ratio face gear drive after the establishment of enveloping coordinate systems. Then combining with equation of generating surface, the tooth surface equation of the face gear is obtained. The three-dimensional model of orthogonal fluctuating gear ratio face gear is acquired on the basis of a modeling program, which is developed under the environment of VB and Solidworks (API). Furthermore, localization of the bearing contact is achieved by the manufacturing method and it is justified by the finite element method analysis result. Finally, the kinematics of the orthogonal fluctuating gear ratio face gear drive is analyzed, and the change laws of transmission ratio, angular displacement and angular acceleration of the face gear are acquired.


Author(s):  
Yih-Jen Dennis Chen

Abstract This paper presents the kinematic study of the face gear drive system. The study includes three different configurations which are: (1) the on-center orthogonal face gear drive, (2) the on-center non-orthogonal face gear drive, and (3) the offset orthogonal face gear drive. The mathematical description for the gear meshing and the resulting face gear tooth surface is developed. This paper also presents the criteria for detecting the limitation of the effective face width due to tooth pointing and undercutting. The technique presented is applied to develop a computer program. This design automation tool allows visualizing the gear meshing and tooth geometry of the face gear drive.


2013 ◽  
Vol 819 ◽  
pp. 100-104
Author(s):  
Xue Yu Peng ◽  
Qing Li ◽  
Tai Yong Wang

The face gear tooth surface theoretical equation, based on the mesh of curved tooth face gear and involute worm, was deduced by means of differential geometry, meshing theory and so on. According to the conditions of the gear meshing, studying the ideal contract-point trace line theoretical equation under the conditions of no machining errors, installation errors and so on. By solving the equations and simulating in SOLIDWORKS, finally the tooth contact situation of face gear and cylindrical worm in the meshing process was got.


Author(s):  
Xian-Long Peng

The conventional tooth surface of a face gear is difficult to manufacture, and the cutter for the face gear cutting is not uniform even though the parameters of the pinion mating with the face gear slightly change. Based on the analysis of the geometry features of the tooth surface, a new developable ruled surface is defined as the tooth flank of the face gear, for which the most important geometry feature is that the flank could be represented by a family of straight lines, hence it could be generated by a straight-edged cutter. The mathematical models of the new ruled tooth surface, the cutter and the generation method are presented, the deviation between the ruled surface and the conventional surface, the correction of the ruled surface to reduce the deviation are investigated through numerical examples. The manufacturing process is simulated by VERICUT software, and the results demonstrate that even when the principle deviation is added to the machined deviation, the absolute deviation is on the micro-scale. The meshing and contact simulation shows that the new surface could obtain good meshing performance when the number of face gear teeth is greater than three times the number of pinion teeth. This research provides a new method for manufacturing face gears.


2012 ◽  
Vol 479-481 ◽  
pp. 944-948 ◽  
Author(s):  
Dian Hua Chen ◽  
Zhong Wei Zhang

A practical method based on normal gaps topography is proposed here for loaded tooth contact analysis of WN gear having tooth surface deviations. The simulation of meshing state and tooth strength of WN gear are provided with real tooth surfaces. In the study normal gaps distribution is adopted to calculate tooth surface contact elastic deformation and local deviations due to manufacturing errors and tooth surface wear. For WN gear, the loaded distribution on the contact zone in meshing tooth surface has not been investigated because of their complexity in the contact state. The finite element method is adopted to analyze the contact pattern and tooth strength. The study has concretely calculated the contact pressure and zone of meshing in different loaded and transmission error. At the end examples are analyzed to demonstrate the effectiveness of the proposed method in quantifying effect of such deviations on the loaded distribution and tooth stress distribution.


2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985951 ◽  
Author(s):  
Lei Liu ◽  
Jinzhao Zhang

This article presents a sphere–face gear pair by substituting the convex spherical gear for the pinion of a conventional face gear pair. The sphere–face gear pair not only maintains the advantages of the face gear pair with a longitudinally modified pinion but also allows variable shaft angles or large axial misalignments. Meshing characteristics of the proposed gear pair are studied in this article. The mathematical models of the sphere–face gear pair are derived based on machining principles. The tooth contact analysis (TCA) and curvature interference check are conducted for the sphere–face gear pair with variable shaft angles. The loaded TCA is also implemented utilizing the finite element method. The results of numerical examples show that proposed gear pair has the following features. Geometrical transmission error of constant shaft angle or varying shaft angle is zero; contact points of the sphere–face gear set with variable shaft angle are located near the centre region of face gear tooth surface; there is no curvature interference in meshing; and transmission continuity of the gear pair can be guaranteed in meshing.


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