scholarly journals Investigation of the Effect of Geometry Characteristics on Bending Stress of Asymmetric Helical Gears by Using Finite Elements Analysis

Computation ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 19
Author(s):  
Andromachi-Efsevia Zouridaki ◽  
George Vasileiou
Keyword(s):  
Computer Aided Design ◽  
Gear Tooth ◽  
Design Procedure ◽  
The Other ◽  
Geometrical Shape ◽  
Bending Stress ◽  
Finite Elements Analysis ◽  
Element Analysis ◽  
Helical Gears ◽  
Bending Loads

Asymmetric helical gears have been under investigation for more than two decades due to their inherent ability to handle greater bending loads than their spur counterparts of comparable size (i.e., the number of teeth and module). For this type of gear, only one side of each gear tooth in a geared mechanism is usually loaded (driving/driven side), whereas the other remains mostly unloaded (coast side). Due to the asymmetry of the tooth, a nonlinear model is used. For that reason, a numerical design procedure is introduced involving the geometrical and structural modelling of conjugate helical gear sets. This is accomplished with the tool of Finite Element Analysis (FEA) which is presented to the scientific literature. The basic geometry is initially generated in 2D and thereafter converted to a 3D shape using Boolean operations. The rigid body which is necessary for FEA software is produced from Computer Aided Design (CAD) software (SolidWorks). This paper is focused on the effect analysis of different geometry characteristics on bending loads. The effects on bending stress play a significant role in gear design wherein its magnitude is controlled by the nominal bending stress and the stress concentration due to the geometrical shape of the teeth. The analysis of this effect of the different geometrical characteristics in the load is presented in detail. Moreover, a comparison of the stresses that are developed between pairs with asymmetrical helical teeth by keeping one geometric parameter constant and modifying the values of the other two parameters is presented.

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.

Computer-Aided Gear Product Realization

2018 ◽  
Author(s):  
Alireza Yazdanshenas ◽  
Emilli Morrison ◽  
Chung-Hyun Goh ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Computer Aided Design ◽  
Interaction Analysis ◽  
Gear Tooth ◽  
Integrated Design ◽  
System Level ◽  
Trial And Error ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Gear Design ◽  
Computer Aided

To save time and resources, many are making the transition to developing their ideas virtually. Computer-aided gear production realization is becoming more and more desired in the industry. To produce gears with custom qualities, such as material, weight and shape, the trial and error approach has yielded the best results. However, trial and error is costly and time consuming. The computer-aided integrated design and manufacturing approach is intended to resolve these drawbacks. A simple one stage reduction spur gearbox is used as an example in a case study. First, the gear geometry is developed using computer aided design (CAD) modeling. Next, using MATLAB/Simulink, the gear assembly is connected virtually to other subsystems for system expectations and interaction analysis. Finally, using finite element analysis (FEA) tools such as ABAQUS, a dynamic FEA of the gear integration is completed to analyze the stress concentrations and gear tooth failures. Through this method of virtual gear design, customized dimensions and specifications of gears for satisfying system-level requirements can be developed, thereby saving time and manufacturing costs for any custom gear design request.

A Computational Geometry for the Blades and Internal Flow Channels of Centrifugal Compressors

1983 ◽  
Vol 105 (2) ◽  
pp. 288-295 ◽  
Author(s):  
M. V. Casey
Keyword(s):  
Computational Geometry ◽  
Computer Aided Design ◽  
Design Procedure ◽  
Internal Flow ◽  
Geometrical Shape ◽  
Parametric Form ◽  
Centrifugal Compressors ◽  
Flow Channels ◽  
Computer Aided ◽  
Aided Design

A new computational geometry for the blades and flow passages of centrifugal compressors is described and examples of its use in the design of industrial compressors are given. The method makes use of Bernstein-Bezier polynomial patches to define the geometrical shape of the flow channels. This has the following main advantages: the surfaces are defined by analytic functions which allow systematic and controlled variation of the shape and give continuous derivatives up to any required order: and the parametric form of the equations allows the blade and channel coordinates to be very simply obtained at any number of points and in any suitable distribution for use in subsequent aerodynamic and stress calculations and for manufacture. The method is particularly suitable for incorporation into a computer-aided design procedure.

scholarly journals Effects of Rim Thickness on Spur Gear Bending Stress

1994 ◽  
Vol 116 (4) ◽  
pp. 1157-1162 ◽  
Author(s):  
G. D. Bibel ◽  
S. K. Reddy ◽  
M. Savage ◽  
R. F. Handschuh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Power ◽  
Design Parameter ◽  
Gear Tooth ◽  
Spur Gear ◽  
Bending Stress ◽  
Element Analysis ◽  
Bending Stresses

Thin rim gears find application in high-power, lightweight aircraft transmissions. Bending stresses in thin rim spur gear tooth fillets and root areas differ from the stresses in solid gears due to rim deformations. Rim thickness is a significant design parameter for these gears. To study this parameter, a finite element analysis was conducted on a segment of a thin rim gear. The rim thickness was varied and the location and magnitude of the maximum bending stresses reported. Design limits are discussed and compared with the results of other researchers.

A Computational Geometry for the Blades and Internal Flow Channels of Centrifugal Compressors

1982 ◽  
Author(s):  
M. V. Casey
Keyword(s):  
Computational Geometry ◽  
Computer Aided Design ◽  
Design Procedure ◽  
Internal Flow ◽  
Geometrical Shape ◽  
Parametric Form ◽  
Centrifugal Compressors ◽  
Flow Channels ◽  
Computer Aided ◽  
Aided Design

A new computational geometry for the blades and internal flow passages of centrifugal compressors is described and examples of its use in the design of industrial compressors are given. The method makes use of Bernstein-Bezier polynomial patches to define the geometrical shape of the flow channels. This has the following main advantages: the surfaces are defined by analytic functions which allow systematic and controlled variation of the shape and give continuous derivatives up to any required order; and the parametric form of the equations allows the blade and channel coordinates to be very simply obtained at any number of points and in any suitable distribution for use in subsequent aerodynamic and stress calculations and for manufacture. The method is particularly suitable for incorporation into a computer aided design procedure.

Design and Analysis of Internal Gears With Different Rim Thickness and Shapes

2015 ◽  
Author(s):  
F. Karpat ◽  
S. Ekwaro-Osire ◽  
T. G. Yilmaz ◽  
O. Dogan ◽  
C. Yuce
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Gear Tooth ◽  
Weight Ratio ◽  
Bending Stress ◽  
Element Analysis ◽  
Fillet Radius ◽  
Tooth Stiffness ◽  
Bending Stresses ◽  
Internal Gear

In recent years, thanks to their significant advantages such as compactness, large torque-to-weight ratio, large transmission ratios, reduced noise and vibrations, internal gears have been used in automotive and aerospace applications especially in planetary gear drives. Although internal gears have a number of advantages, they have not been studied sufficiently. Internal gears are manufactured by pinion type cutters which are nearly identical with pinion gear except the addendum factor which is 1.25 instead of 1. The tip geometry of a pinion type cutter which determines the fillet of internal gear tooth can be sharp or rounded. In this study, the design of internal gears were investigated by using a traditional approach. Mathematical equations of pinion type cutter were obtained by using differential geometry, then the equations of internal gear tooth were derived accurately by using coordinate transformations and relative motion between the pinion type cutter and internal gear blank. A computer program was generated to attain points of internal gear teeth and three dimensional design of complete gear. 20°-20° were used as pressure angle. To find optimum internal gear geometry, different rim thicknesses and shapes are tried out for finite element analyses. There were several parameters that were shown to effect the performance of the internal gears, with tooth stiffness being the most significant parameter. Tooth stiffness was also vitally influence the dynamic analysis. In order to compute gear tooth stiffness of the internal gear with various rim thicknesses and shapes, finite element analysis was used. A static analysis was performed to assess the gear bending stress and tooth displacement. Tetrahedral element type was selected for meshing. The internal gear outer ring was fixed and the force of 2500 N was applied on the tooth. According to the displacement values from the analysis internal gear tooth stiffness were calculated individually. Additionally, the effect of root bending stress with varying rim thickness, shapes, and root radius were investigated. The bending stresses were calculated according to ISO 6336 and using finite element analysis were shown to be in good agreement. It was shown that when the rim thickness and fillet radius were increased, the maximum bending stresses decreased considerably. As rim thickness was increased, the maximum bending stress decreased nearly 23%. It was also shown that as the fillet radius decreased, the maximum bending stress increased, whereas the rim stresses slightly changed. As the fillet radius was decreased, the maximum bending stress increased nearly 10%. It was also observed that when rim thickness was increased, the stress on the rim was decreased, whereas tooth stiffness was increased. However, fillet radius had no visible effect both on rim stress and tooth stiffness. Furthermore, it was shown that the rim shape had significant effect on rim stress.

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.

Finite Element Analysis on Bending Stress of Generating Spur Bevel Gear Based on ANSYS

2012 ◽  
Vol 490-495 ◽  
pp. 2546-2549
Author(s):  
De Li Cui ◽  
Yi Tong Li ◽  
Hong Zhuang Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Design Theory ◽  
Data Exchange ◽  
Gear Tooth ◽  
Bevel Gear ◽  
Bending Stress ◽  
Element Analysis ◽  
Element Method

The meshing generating spur bevel gear is presented by the method for precise modeling of gear in software Catia. Then by the excellent data exchange interface between Catia and ANSYS, the model can be transferred into ANSYS and bending stress of the gear tooth is calculated with finite element method ( FEM),which proposed design theory basis of generating spur bevel gear.

The Use of Bezier Polynomial Patches to Define the Geometrical Shape of the Flow Channels of Compressors

1988 ◽  
Author(s):  
Wang Qinghuan ◽  
Huang Xiaoyan
Keyword(s):  
Computer Aided Design ◽  
Design Procedure ◽  
Spanwise Direction ◽  
Geometrical Shape ◽  
Construction Process ◽  
Load Models ◽  
Flow Channels ◽  
Aided Design ◽  
Further Development ◽  
Surface Construction

Based on the method of Casey (1), the present paper makes further development in using Bezier polynomial patches to define the geometrical shape of the flow channels of compressors. There are two advantages in this new method. First, in the geometrical construction process the blade profile and the contour of impeller’s meridional channel can be given by the same number of patches of the same degree so as to avoid more complicated repeat computations. Second, for curved surface construction there are no restrictions of linearity in the spanwise direction in order to match the distribution of flow angles at the inlet better and to fit the needs of various load models. Some examples have shown that the shapes produced by Bezier polynomial patches are general enough to be used in the design of new compressors and in approximation of the geometry of existing ones. The method is particularly suitable for incorporation into a computer-aided design procedure.

Contact Stress Analysis of a Helical Gear

2015 ◽  
Vol 766-767 ◽  
pp. 1070-1075 ◽  
Author(s):  
R. Devaraj
Keyword(s):  
Stress Analysis ◽  
Contact Stress ◽  
Gear Tooth ◽  
Element Model ◽  
Helix Angle ◽  
Helical Gear ◽  
Bending Stress ◽  
Helical Gears ◽  
Modeling Software ◽  
Main Factors

The main factors that cause the failure of gears are the bending stress and contact stress of the gear tooth. Out of these, failure of gears due to contact stress is high compared to bending stress. Stress analysis has been a key area of research to minimize failure and optimize design. This paper gives a finite element model for introspection of the stresses in the tooth during the meshing of gears. Specifically, helix angle is important for helical gears. Using modeling software, 3-D models for different helix angles in helical gears were generated, and the simulation was performed using ANSYS 12.0 to estimate the contact stress. The Hertz equation and AGMA standard was used to calculate the contact stress. The results of the theoretical contact stress values, using Hertz and AGMA are compared with the stress values from the FEA for different helix angles and the results are tabulated and discussed.

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