scholarly journals Influence of asymmetric factor on spur gears to dynamic bending stress

2021 ◽  
Vol 1034 (1) ◽  
pp. 012010
Author(s):  
Agus Sigit Pramono ◽  
Mohamad Zainulloh Rizal
Keyword(s):  
Spur Gears ◽  
Bending Stress ◽  
Dynamic Bending ◽  
Asymmetric Factor

scholarly journals A Novel Method for Tooth Bending Stress Calculation of Gears With Asymmetric Teeth

2021 ◽  
Author(s):  
Oguz DOGAN ◽  
Celalettin YUCE ◽  
Fatih KARPAT
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Experimental Studies ◽  
Element Model ◽  
Bending Stress ◽  
Element Analysis ◽  
Stress Calculation ◽  
Bending Stresses ◽  
New Equation ◽  
Asymmetric Factor

Abstract Today, gear designs with asymmetric tooth profiles offer essential solutions in reducing tooth root stresses of gears. Although numerical, analytical, and experimental studies are carried out to calculate the bending stresses in gears with asymmetric tooth profiles a standard or a simplified equation or empirical statement has not been encountered in the literature. In this study, a novel bending stress calculation procedure for gears with asymmetric tooth profiles is developed using both the DIN3990 standard and the finite element method. The bending stresses of gears with symmetrical profile were determined by the developed finite element model and was verified by comparing the results with the DIN 3990 standard. Using the verified finite element model, by changing the drive side pressure angle between 20° and 30° and the number of teeth between 18 and 100, 66 different cases were examined and the bending stresses in gears with asymmetric profile were determined. As a result of the analysis, a new asymmetric factor was derived. By adding the obtained asymmetric factor to the DIN 3390 formula, a new equation has been derived to be used in tooth bending stresses of gears with asymmetric profile. Thanks to this equation, designers will be able to calculate tooth bending stresses with high precision in gears with asymmetric tooth profile without the need for finite element analysis.

Computer Aided Analysis of Bending Strength of Involute Spur Gears with Asymmetric Profile

2004 ◽  
Vol 127 (3) ◽  
pp. 477-484 ◽  
Author(s):  
Kadir Cavdar ◽  
Fatih Karpat ◽  
Fatih C. Babalik
Keyword(s):  
Computer Program ◽  
Bending Strength ◽  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Computer Aided Analysis ◽  
Tooth Form ◽  
Stress Concentration Factors ◽  
Stress Minimization

This paper presents a method for the determination of bending stress minimization of involute spur gears. A computer program has been developed to investigate the variation of bending stress and contact ratio depending on the pressure angle on the drive side. Since asymmetric tooth is not standard, the tooth model, which was introduced by DIN 3990/Method C and ISO/TC 60, has been adjusted for asymmetric tooth by the authors. The determination of the tooth form and stress concentration factors for asymmetric tooth has been accomplished for each different parameter (pressure angles, tool radius, rack shift, etc.). The sample results, which were obtained by using a developed computer program, are illustrated with numerical examples.

Spontaneous Degradation of Flexible Poly-Si TFTs Subject to Dynamic Bending Stress

2019 ◽  
Vol 66 (5) ◽  
pp. 2214-2218 ◽  
Author(s):  
Wei Jiang ◽  
Mingxiang Wang ◽  
Huaisheng Wang ◽  
Dongli Zhang
Keyword(s):  
Bending Stress ◽  
Dynamic Bending

The Changing Law of Tooth Bending Stress for Herringbone Gears with High Contact Ratio

2010 ◽  
Vol 139-141 ◽  
pp. 965-969 ◽  
Author(s):  
Le Hao Chang ◽  
Geng Liu
Keyword(s):  
Maximum Stress ◽  
Bending Strength ◽  
Maximum Load ◽  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Load Distributions ◽  
Generating Method ◽  
Definition Of ◽  
Herringbone Gear

From the principle of generating method, the precise model of an involute herringbone gear was built. The accurate load distributions of herringbone gear were obtained in different meshing positions in linear programming method. Then the changing course of root bending stress along with the variation of meshing position was gained. The calculation process realized the automatic definition of loads and boundary conditions, and found out the value and the position when the tooth root has maximum bending stress. The results showed that the maximum stress usually appears near the position when the tooth bears maximum load. Be different from spur gears, the maximum stress of herringbone gears will possibly appear in the section where more teeth couples are engaged. The analysis can effectively provide reference for checking tooth bending strength of herringbone gears.

A New Photoelastic Investigation of the Dynamic Bending Stress of Spur Gears

2003 ◽  
Vol 125 (2) ◽  
pp. 365-372 ◽  
Author(s):  
Ming-Jong Wang
Keyword(s):  
Critical Points ◽  
Gear Tooth ◽  
Spur Gear ◽  
Behavioral Characteristics ◽  
Spur Gears ◽  
Bending Stress ◽  
Dynamic Effects ◽  
Contact Points ◽  
Photoelastic Investigation ◽  
Bending Stresses

In this paper, the maximum tensile bending stress (MTBS) and the critical point in the root fillet of spur gear tooth during transmission are determined by a digital photoelastic system involving real time imaging. The behavioral characteristics of the bending stresses of the gear tooth are analyzed at different rotation speeds, transmitted torques, and contact points. Then, the dynamic effects, the various critical points and the maximum tensile bending stresses are compared experimentally and theoretically, and discussed. Finally, the best approaches for determining the maximum bending stress and its position in the root fillet of spur gear tooth are recommended.

Simplified Spur Gear Design

2016 ◽  
Author(s):  
Edward E. Osakue
Keyword(s):  
Contact Stress ◽  
Design Method ◽  
Spur Gear ◽  
Load Factor ◽  
Spur Gears ◽  
Bending Stress ◽  
Hertz Contact ◽  
Gear Design ◽  
Simplified Method ◽  
The Difference

A simplified design method (SDM) for spur gears is presented. The Hertz contact stress and Lewis root bending stress capacity models for spur gears have been reformulated and formatted into simplified forms. A scheme is suggested for estimating the AGMA J-factor in Lewis root bending stress for spur gears from a single curve for both pinion and gear instead of the conventional two curves. A service load factor is introduced in gear design that accounts for different conventional rated load modifier factors. It represents a magnification factor for the rated load in a gear design problem. Two design examples are considered for applications of the stress capacity models. In Example 1, the Hertz contact stress of the SDM deviates from AGMA value by 1.95%. The variance in Example 2 between the contact stress of the SDM and FEM is 1.184% while that between SDM and AGMA is 0.09%. The root bending stress of AGMA and SDM for the pinion in Example 1 differs by 1.44% and that for the gear by 6.59%. The difference between the root bending stress of AGMA and SDM for pinion and gear in Example 2 is 0.18%. These examples suggest that the new simplified method gives results that compare very favorably with both AGMA and FEM solutions. The simplified method developed is recommended mainly for preliminary design when quick but reliable solutions are sought.

scholarly journals Real contact ratio and tooth bending stress calculation for plastic/plastic and plastic/steel spur gears

2021 ◽  
Vol 22 ◽  
pp. 30
Author(s):  
Toni Jabbour ◽  
Ghazi Asmar ◽  
Mohamad Abdulwahab ◽  
Jose Nasr
Keyword(s):  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Stress Variation ◽  
Real Contact ◽  
Number Of Teeth ◽  
Effective Contact ◽  
Critical Configurations ◽  
Plastic Gears ◽  
Plastic Steel

This paper presents an iterative method for calculating the effective contact ratio and the bending tooth stress for a pair of plastic/plastic and plastic/steel spur gears with an involute profile. In this method, the pinion and the gear are modeled, at each moment of the mesh cycle, as equivalent springs in parallel undergoing the same displacement along the line of action. This leads to the calculation of the bending stress by taking into account the number of teeth initially in contact and those which enter in contact prematurely. We also investigate the influence of certain gear parameters, such as, the number of teeth, the pressure angle, and the module on the behavior of a pair of meshed gears. In addition, the variation of the bending stress at the tooth fillet is investigated for a pair of plastic/plastic and a pair of plastic/steel spur gears, in order to determine the critical configurations for which the bending stress is maximum. In general, the results obtained from the present method also show that the stress variation in plastic/plastic gears differs markedly from that in plastic/steel gears.

Compact Design of High-Contact-Ratio Spur Gears

2020 ◽  
Author(s):  
Tuan H. Nguyen
Keyword(s):  
Spur Gear ◽  
Operating Parameters ◽  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Dynamic Design ◽  
Compact Design ◽  
Profile Errors ◽  
Tooth Profile Errors ◽  
Root Stress

Abstract This study presents a computer simulation for the dynamic design of compact high-contact-ratio spur gear transmissions. High contact ratio gears have the potential to produce lower dynamic tooth loads and minimum root stress but they can be sensitive to tooth profile errors. The analysis presented in this work was performed by using the NASA gear dynamics code DANST (Dynamic Analysis of Spur Gear Transmissions). In the analysis, the addendum ratio (addendum/diametral pitch) was varied over the range 1.30 to 1.40 to obtain a contact ratio of 2.00 or higher. The constraints of bending stress limit and involute interference provide the main criteria for this investigation. Compact design of high-contact-ratio gears with different gear ratios and pressure angles was investigated. Comparison of compact design between low-contact-ratio and high-contact-ratio gears was conducted. With the same operating parameters, high-contact-ratio gears appear to have much more compact design than low-contact-ratio gears. For compact design of high-contact-ratio gears, a diametral pitch of 6.00 appears to be the best choice for an optimal gear set.

Search method applied for gear tooth bending stress prediction in normal contact ratio asymmetric spur gears

2018 ◽  
Vol 232 (24) ◽  
pp. 4647-4663 ◽  
Author(s):  
Benny Thomas ◽  
K Sankaranarayanasamy ◽  
S Ramachandra ◽  
SP Suresh Kumar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Gear Tooth ◽  
Search Method ◽  
International Organization ◽  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Element Analysis ◽  
Normal Contact

Various analytical methods have been developed by designers to predict gear tooth bending stress in asymmetric spur gears with an intention to improve the accuracy of predicted results and to reduce the need for time consuming finite element analysis at the early stages of gear design. Asymmetry in the drive and coast side of asymmetric spur gears poses difficulty in direct application of well-known procedures like American Gear Manufacturers Association and International Organization for Standardization in the prediction of gear tooth bending stress. In earlier works, ISO-6336-3 methodology was suitably modified and adapted to predict asymmetric spur gear tooth bending stress. This approach is based on certain assumptions on the location of critical section which could introduce error in the predicted maximum bending stress. The present work is to analytically predict gear tooth bending stress in normal contact ratio asymmetric spur gears based on a more rigorous analytical approach. This includes a fundamental study on the gear tooth orientation used to define the coordinate system, determination of maximum bending stress by search along the fillet profile and to obtain stress profile along the fillet. Gear tooth bending stress obtained from the present work using Search method is compared against the results obtained from earlier adapted International Organization for Standardization method and Finite Element Analysis. This study recommends a new coordinate system and method for analytical prediction of gear tooth bending stress in normal contact ratio asymmetric spur gears.

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