Computer Simulation Analysis of Bending Stress for Face Gear with a New Type Fillet Tooth Surface

2011 ◽  
Vol 86 ◽  
pp. 411-414
Author(s):  
Yun Bo Shen ◽  
Jie Gao ◽  
Wen Qiang Ding

Bending stress is a principal factor that defines the fatigue life of face gear. A new tooth surface structure with circular arc of fillet surface for the face gear has been developed. A method of processing or cutting of fillet surfaces of helical face gear by application of a shaper with tooth rounded top has also been represented. The bending stress of the tooth of face gear with new surface structure has been performed by computer simulation. Two versions of finite element model of tooth surfaces of face gear are generated by application of numerical technology. One version is based on the cutting shaper with tooth top shaper corner and another version is with addendum rounded top. Tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA) for the two versions of face gear drives with helical spur gear are also considered. The results of simulation show that the bending stress of tooth surface of the face gear with fillet surface generated by the rounded top of the shaper is 12% lower than the first version’s.

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.


1997 ◽  
Vol 119 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Y. Zhang ◽  
Z. Wu

This paper presents a detailed investigation on the manufacturing, tooth geometry and contact characteristics of face gear drives with offset axes. In the paper, the tooth geometry of offset face gears is analytically determined by simulating the conjugate motion between the gear and the cutting tool in the generation process. Design criteria are established for the optimal tooth element proportions of offset face gears that avoid tooth undercutting and pointing. The tooth surface geometry of the gear member of the drive is modified by using a shaper that resembles the pinion in profile but has a few more teeth than the pinion to localize the tooth contact. The contact characteristics of the offset face gears are analyzed by a tooth contact analysis (TCA) program that simulates the meshing process of the gear drive assembled under misalignment. An example of offset face gear design and contact analysis is included in the paper.


2011 ◽  
Vol 86 ◽  
pp. 327-332
Author(s):  
Jin Hua Wang ◽  
Yun Bo Shen ◽  
Ze Yong Yin ◽  
Jie Gao ◽  
Yan Ying Jiang

Load sharing is one of the main factors that determine gear strength. In this paper, Tooth Contact Analysis (TCA) and Loaded Tooth Contact Analysis (LTCA) have been performed to investigate the effect of tooth surface modification on the contact ratio, load sharing and strength of an orthogonal offset face gear drive with spur involute pinion. The results indicate that the contact ratio of 2.0 or higher could be achieved. The maximum load carried by single tooth and bending stress are significantly reduced when appropriate tooth surface modification is applied to the orthogonal offset face gear drive.


Author(s):  
J-L Li ◽  
S-T Chiou

An innovative modified spur gear with crowned teeth and its generating mechanism are proposed in this study. The main purpose of tooth surface modification is to change line contact to point contact at the middle of gear tooth surfaces in order to avoid edge contact resulting from possible unavoidable axial misalignment. Moreover, the surface of one gear tooth can be generated with just one cutting process, thereby facilitating easy manufacturing. Based on gearing theory, the model for surface design is developed. A tooth contact analysis (TCA) model for the modified gear pair is also built to investigate meshing characteristics, so that transmission errors (TEs) under assembly errors can also be studied. Examples are included to verify the correctness of the models developed and to demonstrate gear characteristics.


2010 ◽  
Vol 139-141 ◽  
pp. 1154-1157 ◽  
Author(s):  
Hui Guo ◽  
Ning Zhao ◽  
Hao Gao

This paper proposes a modification method for tooth surface of face gear drive with a grinding worm on a numerical grinding machine. The surface equation of grinding worm is derived, and the coordinate System of generating the worm is established. Tooth contact analysis (TCA) is performed to investigate the performance of face gear drive before and after modification, and the alignment error is considered. This method can obtain a more stable bearing contact in contrast to the method by increasing tooth number of shaper. The longitudinal bearing contact on the face-gear tooth surface has been obtained which will increase the contact ratio. By modification the edge contact at surface edges of the gears can be avoided and the modification magnitude can be controlled freely.


Author(s):  
Layue Zhao ◽  
Robert C Frazer ◽  
Brian Shaw

With increasing demand for high speed and high power density gear applications, the need to optimise gears for minimum stress, noise and vibration becomes increasingly important. ISO 6336 contact and bending stress analysis are used to determine the surface load capacity and tooth bending strength but dates back to 1956 and although it is constantly being updated, a review of its performance is sensible. Methods to optimise gear performance include the selection of helix angle and tooth depth to optimise overlap ratio and transverse contact ratio and thus the performance of ISO 6336 and tooth contact analysis methods requires confirmation. This paper reviews the contact and bending stress predicted with four involute gear geometries and proposes recommendations for stress calculations, including a modification to contact ratio factor Zɛ which is used to predict contact stress and revisions to form factor YF and helix angle factor Yβ which are cited to evaluate bending stress. The results suggest that there are some significant deviations in predicted bending and contact stress values between proposal methods and original ISO standard. However, before the ISO standard is changed, the paper recommends that allowable stress numbers published in ISO 6336-5 are reviewed because the mechanisms that initiate bending and contact fatigue have also changed and these require updating.


Lubricants ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 20 ◽  
Author(s):  
Gajarajan Sivayogan ◽  
Ramin Rahmani ◽  
Homer Rahnejat

Energy efficiency and functional reliability are the two key requirements in the design of high-performance transmissions. Therefore, a representative analysis replicating real operating conditions is essential. This paper presents the thermoelastohydrodynamic lubrication (TEHL) of meshing spur gear teeth of high-performance racing transmission systems, where high generated contact pressures and lubricant shear lead to non-Newtonian traction. The determination of the input contact geometry of meshing pairs as well as contact kinematics are essential steps for representative TEHL. These are incorporated in the current analysis through the use of Lubricated Loaded Tooth Contact Analysis (LLTCA), which is far more realistic than the traditional Tooth Contact Analysis (TCA). In addition, the effects of lubricant and flash surface temperature rise of contacting pairs, leading to the thermal thinning of lubricant, are taken into account using a thermal network model. Furthermore, high-speed contact kinematics lead to shear thinning of the lubricant and reduce the film thickness under non-Newtonian traction. This comprehensive approach based on established TEHL analysis, particularly including the effect of LLTCA on the TEHL of spur gears, has not hitherto been reported in literature.


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