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.

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.

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.

scholarly journals ANALISA HASIL UJI KEKUATAN TARIK, TEKAN & STRUKTUR MAKRO SAMPAH PLASTIK JENIS PET, HDPE, DAN CAMPURAN (PET+HDPE)

JTAM ROTARY ◽  
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Holy Ramagisandy ◽  
Rudi Siswanto
Keyword(s):  
Tensile Strength ◽  
Bending Strength ◽  
Maximum Load ◽  
Bending Test ◽  
Stress And Strain ◽  
Bending Stress ◽  
Test Results ◽  
Recycled Pet ◽  
Tensile Strength Test ◽  
Used Oil

Plastik is a material which has difficult to decompose. Therefore, the utilization of waste into useful material is important to do. This study aims to identify the tensile strength, bending, and macro structure of recycled PET, HDPE, and PET + HDPE plastik waste mixtures and recommendations for plastik products that fit the characteristics of these plastik types. PET and HDPE plastik waste is melted with oil and reprinted into tensile and bending test samples in accordance with predetermined variations, and then the results of the fracture are analyzed in a macro structure. Based on tensile testing, the tensile strength test results have the highest stress and strain values obtained in the mixture of 40% + HDPE 60% (B2) used oil specimens of 10.58 MPa and strain values of 11.98%. The results of bending strength testing which has the highest bending stress value and maximum load value are obtained in plastik mixture specimens with 30% used oil mixture + 70% HDPE (B1) of 11.58 MPa and for maximum load values of 43.33 KN. Testing the tensile strength and bending strength of the type of plastik mixture Oil and HDPE + PET (50%: 50%), the results obtained can still not be recommended to be used as a paving block product because the value of stress, strain, bending stress, and the maximum load is still relatively low, namely for the tensile test the highest variation of stress value is 5.21 MPa, the highest variation of strain value is 5.23%, the maximum load value is 10 KN, and the highest variation of bending stress value is 40% + 60% by 4.01 MPa.

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.

Effect of Drive Side Contact Ratio on Direct Design Asymmetric High Contact Ratio Spur Gear Based on Load Sharing

2014 ◽  
Vol 592-594 ◽  
pp. 2292-2296 ◽  
Author(s):  
P. Marimuthu ◽  
G. Muthuveerappan
Keyword(s):  
Parametric Design ◽  
Load Sharing ◽  
Spur Gear ◽  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Normal Contact ◽  
Critical Loading ◽  
Direct Design ◽  
Single Tooth

The aim of this paper is to determine the effect on direct design asymmetric high contact ratio spur gear based on tooth load sharing. A unique Ansys parametric design language code is developed for this study. The load sharing based bending and contact stresses are determined for different drive side contact ratios. In addition to that the location of critical loading point is determined. Because the critical loading point for high contact ratio spur gear not lies on fixed point like normal contact ratio spur gears namely highest point of single tooth contact. In conclusion an increase in drive side contact ratio leads to increase in the load sharing based bending stress and decrease in the contact stress at the critical loading point.

The Synthesis of Tooth Profile Shapes and Spur Gears of High Load Capacity

1970 ◽  
Vol 92 (3) ◽  
pp. 543-551 ◽  
Author(s):  
A. O. Lebeck ◽  
E. I. Radzimovsky
Keyword(s):  
Bending Strength ◽  
Load Capacity ◽  
High Capacity ◽  
High Hardness ◽  
Spur Gear ◽  
Speed Ratio ◽  
Spur Gears ◽  
Gear Pair ◽  
Contact Ratio ◽  
High Load Capacity

In this work a method is presented for the synthesis of high capacity noninvolute spur gears and tooth profiles. Two gear capacity criteria are used in the synthesis: (1) the capacity based on maximum allowable Hertz stress and (2) the capacity based on the bending strength of the tooth. These capacity criteria are related to a generalized noninvolute gear geometry which includes the factors number of teeth and contact ratio. It was found that there are certain optimal relationships which exist among the noninvolute parameters which lead to a solution, for a maximum capacity noninvolute gear pair. For a speed ratio of one to five it was found that a significant capacity advantage exists for the synthesized noninvolute gear pair (compared to a 20-deg involute spur gear pair) for moderate as well as high hardness values. For a speed ratio of one to one a capacity advantage was found for moderate hardness but the advantage decreased significantly for high hardness.

Optimization of fillet stress to enhance the bending strength through non-standard high contact ratio spur gears

2015 ◽  
Vol 230 (7-8) ◽  
pp. 1139-1148 ◽  
Author(s):  
P Marimuthu ◽  
G Muthuveerappan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Parametric Study ◽  
Bending Strength ◽  
Spur Gear ◽  
Gear Ratio ◽  
Spur Gears ◽  
Contact Ratio ◽  
Element Analysis ◽  
Gear Drives

The present study aims to determine the improvement in the bending strength of the non-standard high contact ratio spur gears based on the balanced (optimum) fillet stress of the pinion and gear. The average number teeth in contact is more than two for high contact ratio gear drives. In the non-standard high contact ratio spur gears, the rack cutter tooth thickness factor is more than 0.5, whereas the standard rack cutter tooth thickness factor is 0.5. The maximum fillet stresses of the pinion and gear is not equal for non-standard high contact ratio spur gear drives when the gear ratio increases. In order to avoid the fatigue failure of the gear, the fillet stresses of the pinion and gear should be balanced. This balanced stress is predicted as the optimum fillet stress. Hence, the present study focuses to optimize the fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear through finite element analysis. Also, a parametric study is carried out to obtain the influence of some gear parameters, such as gear ratio, teeth number in the pinion, pressure angle, addendum height and corrected gear drives (S+, S− and So) on the optimum fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear.

scholarly journals Comparison of Analysis and Experiment for Dynamics of Low-Contact-Ratio Spur Gears

1991 ◽  
Author(s):  
Fred B. Oswald ◽  
Brian Rebbechi ◽  
James J. Zakrajsek ◽  
Dennis P. Townsend ◽  
Hsiang Hsi Lin
Keyword(s):  
Dynamic Load ◽  
High Speed ◽  
Design Tool ◽  
Operating Conditions ◽  
Average Error ◽  
Spur Gears ◽  
Tooth Root ◽  
Bending Stress ◽  
Contact Ratio ◽  
Gear Dynamics

Abstract Low-contact-ratio spur gears were tested in the NASA gear-noise rig to study gear dynamics including dynamic load, tooth bending stress, vibration, and noise. The experimental results were compared with a NASA gear dynamics code to validate the code as a design tool for predicting transmission vibration and noise. Analytical predictions and experimental data for gear-tooth dynamic loads and tooth-root bending stress were compared at 28 operating conditions. Strain gage data were used to compute the normal load between meshing teeth and the bending stress at the tooth root for direct comparison with the analysis. The computed and measured waveforms for dynamic load and stress were compared for several test conditions. These are very similar in shape, which means the analysis successfully simulates the physical behavior of the test gears. The predicted peak value of the dynamic load agrees with the measurement results within an average error of 4.9 percent except at low-torque, high-speed conditions. Predictions of peak dynamic root stress are generally within 10 to 15 percent of the measured values.

Effect of Adjacent Teeth Load on Bending Strength of High Contact Ratio Asymmetrical Spur Gear Drive

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
R. Thirumurugan ◽  
C.C.C. Deepak ◽  
K. Karthieeban
Keyword(s):  
Computer Aided Design ◽  
Bending Strength ◽  
Gear Tooth ◽  
Spur Gear ◽  
Design Tool ◽  
Bending Stress ◽  
Contact Ratio ◽  
Element Analysis ◽  
Gear Drive ◽  
Pressure Angle

This paper describes methodology for predicting the bending stress of the spur gear accurately by including the load on the adjacent teeth for high contact ratio asymmetric spur gear drive. Higher contact ratio is obtained by enlarging the addendum from the standard addendum value where as the asymmetric is achieved by keeping various pressure angles (170, 200 and 220) at non drive side while the drive side pressure angle was kept as 200. The bending stress developed for the given load according to the load sharing calculated by using stiffness based method along with the effect of adjacent teeth loads are explored in this work. Computer aided design tool is used for generating the gear tooth profile and ANSYS is used to carry out the finite element analysis. The result shows that the maximum bending stress level in a mesh cycle is increased when the load on adjacent teeth are taken into account. The higher pressure angle at the non-drive side yields lesser stress at the fillet region when compared to the lower pressure angle.

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