Computational Tooth Root Stress Analysis of Crossed Beveloid Gears with Small Shaft Angle

2011 ◽  
Vol 86 ◽  
pp. 188-191 ◽  
Author(s):  
Chao Sheng Song ◽  
Cai Chao Zhu ◽  
Teik Chin Lim ◽  
Rong Fan
Keyword(s):  
Stress State ◽  
Design Parameter ◽  
Tooth Root ◽  
Tooth Contact Analysis ◽  
Gear Teeth ◽  
Beveloid Gears ◽  
Stress Prediction ◽  
Shaft Angle ◽  
Loaded Tooth Contact Analysis ◽  
Root Stress

It is known that tooth bending failures are directly caused by the stress state at the tooth root or fillet regions of the gear teeth. In this study, the geometric and manufacturing of the fillet and root of crossed beveloid are investigated and a computational tooth stress prediction model is setup applying exact geometry-based mesh theory. The dominate fillet and root design parameter and load were examined in the loaded tooth contact analysis to analyze root stresses.

Coupled Tooth Contact Analysis of Intersected Beveloid Gears for Marine Transmissions

2013 ◽  
Author(s):  
Caichao Zhu ◽  
Haixia Wang ◽  
Mingyong Liu ◽  
Xuesong Du ◽  
Chaosheng Song
Keyword(s):  
Gear Tooth ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Contact Patterns ◽  
Beveloid Gears ◽  
Shaft Angle ◽  
Loaded Tooth Contact Analysis ◽  
Mesh Condition

Beveloid gears are widely applied in fields like ships, automobiles and industrial precision transmissions. In this paper, the formulas of the beveloid gear tooth surface used in marine transmissions were derived and a mesh model for the intersected beveloid gear pair was setup. Then loaded tooth contact analysis was performed using the finite element method considering the coupling of the assembly errors and the elastic deformation of tooth surface. Through the analysis, the influences of assembly errors on contact patterns, mesh force and tooth surface deformations were investigated. In a further step, the tooth profile modifications were performed to alleviate the edge contact and a subsequent major improvement of the mesh condition was obtained. Finally, loaded tooth contact experiments for marine gearboxes with small shaft angle were conducted. The tested results showed good correlation with the computed results. This work may provide some value for the practical design aiming at improved contact characteristics of the beveloid gears with intersected axes.

A precise prediction of the tooth root stresses for involute external gears with any fillet geometry under consideration of the exact meshing condition

2019 ◽  
Vol 233 (21-22) ◽  
pp. 7318-7327 ◽  
Author(s):  
Tobias Paucker ◽  
Michael Otto ◽  
Karsten Stahl
Keyword(s):  
Element Model ◽  
Tooth Root ◽  
Tooth Contact Analysis ◽  
Load Carrying ◽  
Tension And Compression ◽  
Dimensional Boundary ◽  
Precise Prediction ◽  
Exact Relations ◽  
To Receive ◽  
Root Stress

An environmentally friendly design of gearboxes means to increase the utilization of material steadily. This leads to in many ways optimized constructions, which require an exact prediction of occurring stresses under given load-carrying capacity to guarantee sufficient endurance. This paper shows a very precise method to calculate the occurring tooth root stress for involute, external gearings with any form of fillets within a few seconds. A two-dimensional Boundary–Element–Model is used to receive the notch stresses of the fillets which are linked to a high quality analytical tooth contact analysis to consider the exact relations of the gear meshing. The introduced model also allows a calculation of the occurring tension and compression stresses along the whole fillet for different meshing positions. This paper shows the optimization potential by using the described method in comparison to a standard approach.

New Calculation Method for the Load Capacity of Bevel And Hypoid Gears Based on Loaded Tooth Contact Analysis

2011 ◽  
Vol 86 ◽  
pp. 237-242 ◽  
Author(s):  
Bernd Robert Höhn ◽  
Karsten Stahl ◽  
Christian Wirth
Keyword(s):  
Calculation Method ◽  
Load Capacity ◽  
Experimental Investigations ◽  
Tooth Root ◽  
Test Results ◽  
Tooth Contact Analysis ◽  
Hypoid Gears ◽  
Helical Gears ◽  
Bevel Gears ◽  
Loaded Tooth Contact Analysis

At the FZG (Gear Research Centre, Munich, Germany) a research project was carried out to analyze the influence of the hypoid offset on the load capacity of bevel gears by systematic theoretical and experimental investigations. For the experimental investigations two types of bevel gears were designed, one for the pitting tests and one for the tooth root tests. The results of the tooth root tests showed as expected an increasing load capacity with higher offsets. In contrast the pitting tests showed an increasing, but after reaching a maximum, a decreasing load capacity with higher offsets. Regarding the test results a new calculation method was developed that is based on a loaded tooth contact analysis (LTCA). The method is able to consider the local stresses on the flank and in the tooth root. The local strength values are derived out of the standard ISO 6336 for the calculation of helical gears. For bending the local geometry of the tooth root is considered to adopt the strength values of helical gears to bevel and hypoid gears. As a result the local safety factors might be calculated along the face width of pinion and wheel. For pitting the local sliding conditions are taken into account in order to appraise the local lubrication conditions as well as the risk of crack initiations due to shear stresses and higher contact temperatures. The recalculation of the test showed for both types of failure a good correlation between the test results and the calculated values.

scholarly journals Stress calculation on bevel gears with FEM influence vectors

2021 ◽  
Author(s):  
Frederik Mieth ◽  
Carsten Ulrich ◽  
Berthold Schlecht
Keyword(s):  
Load Capacity ◽  
Tooth Contact Analysis ◽  
Tooth Width ◽  
Tooth Stiffness ◽  
Careful Handling ◽  
Coupling Stiffness ◽  
Loaded Tooth Contact Analysis ◽  
Local Root ◽  
Local Stiffness ◽  
Root Stress

AbstractIn order to be able to carry out an optimal gear design with the aim of cost reduction and the careful handling of resources, load capacity is an important criterion for the evaluation of a gear. For the calculation of the flank and root load capacity, a precise loaded tooth contact analysis (LTCA) is necessary. With LTCA software like BECAL, influence numbers are used to calculate the deformation of the gear. These influence numbers are calculated with a BEM-module and considered for calculating the local root stress. This method simplifies the coupling stiffness in tooth width direction with a decay function and neglects the influence of local differences in tooth stiffness. In this publication, this simplification shall be questioned and evaluated.Therefore, a new method for calculating stress with FEM influence vectors is presented. This method enables the calculation of full stress tensors at any desired location in the gear with the efficiency of the influence number method. Additionally, the influence of local stiffness variations in the gear is taken into account. Various gear examples show the influence of material connections at the pinion root and the influence of the rim thickness of a wheel on the root stress. To validate the accuracy and the time efficiency of the new calculation method and to compare the results to current state-of-the-art simulations, a well-documented series of tests from the literature is recalculated and evaluated.

An analysis of the tooth stress distribution of forged bi-metallic gears

2016 ◽  
Vol 232 (1) ◽  
pp. 124-139 ◽  
Author(s):  
Denis J Politis ◽  
Nicholas J Politis ◽  
Jianguo Lin ◽  
Trevor A Dean ◽  
Daniel S Balint
Keyword(s):  
Stress Distribution ◽  
Tooth Root ◽  
Uniform Thickness ◽  
Element Analysis ◽  
British Standard ◽  
Model Simulations ◽  
Gear Teeth ◽  
Forging Process ◽  
Single Material ◽  
Root Stress

The work described in this paper is an evaluation of the contact characteristics of bi-metallic gears forged through a novel bi-metallic gear forging process. Finite element analysis of the contact characteristics of single material gears was first performed to validate the tooth contact and tooth root stresses with empirical American Gear Manufacturers Association and British Standard standards. Having verified the validity of the model, simulations were performed for gears comprising lightweight cores with teeth bounded by steel bands of uniform thicknesses, 1 mm, 2 mm, 4 mm, and 6 mm to evaluate the differences in stress distribution and compare to single material gear teeth. The forged profiles obtained experimentally by utilising 2 mm, 4 mm, and 6 mm thickness bands via the bi-metallic gear forging process are also discussed. The uniform thickness model is subsequently adapted to incorporate the experimental forged profiles in order to estimate the contact stress, root stress, and stress distribution within the teeth to identify performance differences between bi-metallic forged gears and traditional single material gears.

Meshing Stiffness and Tooth Root Stress for Internal Cylindrical Gears With Thin Rim

2003 ◽  
Author(s):  
Jean-Pierre de Vaujany ◽  
Miche`le Guingand ◽  
Didier Remond
Keyword(s):  
3D Model ◽  
Statistical Design ◽  
Tension Stress ◽  
Tooth Root ◽  
Meshing Stiffness ◽  
Cylindrical Gears ◽  
Maximal Tension ◽  
Experiment Method ◽  
Internal Gear ◽  
Root Stress

The main objective of this study is to quantify the influence of the deformation of the rim of an internal gear on the meshing stiffness and the stress distribution in tooth fillets. The 3D model used is based on a method derived from the Finite Prism Method. Tooth bending effects and contact deformations are processed simultaneously. Scientific use of the software has resulted in formulating an equation to calculate the maximal tension stress in the tooth root. This formula has been obtained by using the statistical design of experiment method.

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