scholarly journals A study on force-fitted spur gears in consideration of contact condition (On the internal pressure at the fitting surface and root stress of gear tooth)

1986 ◽  
Vol 52 (480) ◽  
pp. 2187-2193
Author(s):  
Norihisa ARAI ◽  
Eiichi AOYAMA ◽  
Susumu HARADA ◽  
Muneji OKAMOTO ◽  
Tetsuya TOYAO
Keyword(s):  
Internal Pressure ◽  
Gear Tooth ◽  
Contact Condition ◽  
Spur Gears ◽  
Root Stress

An XFEM-Based Approach to Fatigue Crack Growth in Press-Fit Spur Gears

2022 ◽  
pp. 095440892110727
Author(s):  
Fatih Güven
Keyword(s):  
Internal Pressure ◽  
Crack Growth ◽  
Tangential Stress ◽  
Power Transmission ◽  
Gear Tooth ◽  
Tangential Direction ◽  
Spur Gears ◽  
Extended Finite Element ◽  
Interference Fit ◽  
Press Fit

Gears mounted on a shaft via interference fit are the subject of an internal pressure which is essential for power transmission between gear and shaft. The pressure between shaft and gear is responsible for additional stresses occurring both in shaft and gear. This study examines the effect of stresses arising due to the interference on the crack growth that exists at the root of the gear tooth. The numerical analyses were conducted on models having different rim thicknesses by using the extended finite element method that allows mesh-independent crack modeling and does not need re-meshing. The results showed that internal pressure yields additional stresses in the tangential direction. The increment in tangential stress changed the location and intensity of the maximal 1st principal stress and accelerated crack growth. As the tightness of the fit increased, the crack turned towards the rim rather than towards the tooth. As the crack growth through the rim may cause a catastrophic failure of gear, the increment in tangential stress due to internal pressure is crucial for the fatigue life of the gear.

Stress and Mesh Stiffness Evaluation of Bimaterial Spur Gears

2019 ◽  
Author(s):  
Fatih Karpat ◽  
Tufan Gürkan Yılmaz ◽  
Oğuz Doğan ◽  
Onur Can Kalay
Keyword(s):  
Weight Reduction ◽  
Gear Tooth ◽  
High Stress ◽  
Design Parameters ◽  
Spur Gears ◽  
Mesh Stiffness ◽  
Root Region ◽  
Stress Region ◽  
Stress And Deformation ◽  
Root Stress

Abstract Lightweight spur gears have been a trending topic in aerospace and automotive applications recently. Traditionally, weight reduction could be ensured by using gear body with holes or thin rim design which result in to fluctuate mesh stiffness or it may increase stress and deformation levels. Indeed, high stresses occur in only contact and root region of gear tooth during the meshing process, so other regions are subjected to low stress. Based upon this point; various materials with low density and adequate strength could be used in low stress region while gear steel remains for high stress region. In this study, two different lightweight materials (Aluminum alloy and Carbon fiber reinforced polymer) were used for low stress region. The effect of these materials was investigated in view of stiffness and root stress for the same gear design parameters. Unidirectional CFRP laminas were used in a symmetric lay up to ensure quasi-isotropic laminate properties. Finite element analyses were conducted to obtain root stress and then total deformation of the tooth for stiffness calculation. Interface properties of ring and core regions were assumed as pure bonded. Meshing load was applied on the highest point single tooth contact (HPSTC) line. Weight reduction ratios were also compared. According to results, the steel/composite design is superior to steel/aluminum hybrid design in view of stress, stiffness and weight.

Into Mesh Lubrication of Spur Gears With Arbitrary Offset Oil Jet. Part 1: For Jet Velocity Less Than or Equal to Gear Velocity

1983 ◽  
Vol 105 (4) ◽  
pp. 713-718 ◽  
Author(s):  
L. S. Akin ◽  
D. P. Townsend
Keyword(s):  
Inclination Angle ◽  
Gear Tooth ◽  
Optimum Operating ◽  
Spur Gears ◽  
Optimum Operating Condition ◽  
Operating Condition ◽  
The Common ◽  
Jet Velocity ◽  
Oil Jet

An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth. The optimum operating condition for best lubrication and cooling is provided when the oil jet velocity is equal to the gear pitch line velocity with both sides of the gear tooth cooled. When the jet velocity is reduced from pitch line velocity the drive side of the pinion and the unloaded side of the gear is cooled. When the jet velocity is much lower than the pitch line velocity the impingement depth is very small and may completely miss the pinion.

scholarly journals A Method of Selecting Grid Size to Account for Hertz Deformation in Finite Element Analysis of Spur Gears

1982 ◽  
Vol 104 (4) ◽  
pp. 759-764 ◽  
Author(s):  
J. J. Coy ◽  
C. Hu-Chih Chao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Gear Tooth ◽  
Spur Gear ◽  
Grid Size ◽  
Spur Gears ◽  
Element Analysis ◽  
Element Size ◽  
Full Effect ◽  
The Finite Element Analysis

A method of selecting grid size for the finite element analysis of gear tooth deflection is presented. The method is based on a finite element study of two cylinders in line contact, where the criterion for establishing element size was that there be agreement with the classic Hertzian solution for deflection. Many previous finite element studies of gear tooth deflection have not included the full effect of the Hertzian deflection. The present results are applied to calculate deflection for the gear specimen used in the NASA spur gear test rig. Comparisons are made between the present results and the results of two other methods of calculation. The results have application in design of gear tooth profile modifications to reduce noise and dynamic loads.

The torsional stiffness of involute spur gears

2004 ◽  
Vol 218 (1) ◽  
pp. 131-142 ◽  
Author(s):  
J Wang ◽  
I Howard
Keyword(s):  
Finite Element ◽  
Gear Tooth ◽  
Torsional Stiffness ◽  
Spur Gears ◽  
Adaptive Meshing ◽  
Mesh Stiffness ◽  
Finite Element Program ◽  
Tooth Stiffness ◽  
Element Program ◽  
The Individual

This paper presents the results of a detailed analysis of torsional stiffness of a pair of involute spur gears in mesh using finite element methods. Adaptive meshing has been employed within a commercial finite element program to reveal the detailed behaviour in the change over region from single- to double-tooth contact zones and vice versa. Analysis of past gear tooth stiffness models is presented including single- and multitooth models of the individual and combined torsional mesh stiffness. The gear body stiffness has been shown to be a major component of the total mesh stiffness, and a revised method for predicting the combined torsional mesh stiffness is presented. It is further shown tha the mesh stiffness and load sharing ratios will be a function of applied load.

Geometry optimization of the rolling tool for gear roll-forming process

2020 ◽  
pp. 095440542095110
Author(s):  
Bo Peng ◽  
Yang Luo ◽  
Yuanxin Luo ◽  
Ziyong Ma
Keyword(s):  
Gear Tooth ◽  
Geometry Optimization ◽  
Roll Forming ◽  
Utilization Rate ◽  
Forming Process ◽  
Bending Performance ◽  
Maximum Root ◽  
Standard Profile ◽  
Roll Forming Process ◽  
Root Stress

Gear roll forming process is an innovative near-net-shape gear manufacturing technology for efficient manufacturing, high material utilization rate, high products strength, and outstanding surface quality. The profile of the Tooth of the Rolling Tool (TRT) has a direct impact on its strength/stiffness which further affects its life duration and the accuracy of the formed products. Research has been carried out to design the involute curve of TRT, however, the transaction curve of TRT which also has a significant impact on tooth strength and service durability remains to be designed and optimized in order to further improve the rolling performance. In this paper, an elliptical gear tooth root transaction curve is proposed to replace the traditional fillet curve for the enhancement of tooth bending performance. The maximum root stress and stiffness of the gear tooth with elliptical transaction curve are calculated and compared to the standard profile with different parameters (modulus, pressure angle, and coefficient of bottom clearance). The results show that proposed elliptical tooth reduces the maximum root stress and increase the strength and stiffness of TRT especially significant for rolling tools with small number of teeth and coefficient of bottom clearance.

Explicit Parametric Method for Optimal Spur Gear Tooth Profile Definition

2013 ◽  
Vol 633 ◽  
pp. 87-102 ◽  
Author(s):  
Ivana Atanasovska ◽  
Radivoje Mitrovic ◽  
Dejan Momcilovic
Keyword(s):  
Gear Tooth ◽  
Load Capacity ◽  
Parametric Method ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
Element Analysis ◽  
Engineering Research ◽  
Profile Optimization ◽  
Current Engineering

The gear tooth profile has an immense effect on the main operating parameters of gear pairs (load capacity, working life, efficiency, vibrations, etc). In current engineering research and practice, there is a strong need to develop methods for tooth profile optimization. In this paper a new method for selecting the optimal tooth profile parameters of spur gears is described. This method has been named the Explicit Parametric Method (EPM). The addendum modification coefficient, radius of root curvature, and pressure angle of the basic rack for cylindrical gears, have been identified as the main tooth profile parameters of spur gears. Therefore, the EPM selects the optimal values for these three tooth profile parameters. Special attention has been paid to develop a method of adjustment for the particular working conditions and explicit optimization requirements. The EPM for optimal tooth profile parameters of gears uses contact nonlinear Finite Element Analysis (FEA) for calculation of deformations and stresses of gear pairs, in addition to explicit comparative diagrams for optimal tooth profile parameter selection.

scholarly journals An experimental method to measure gear tooth stiffness throughout and beyond the path of contact

2001 ◽  
Vol 215 (7) ◽  
pp. 793-803 ◽  
Author(s):  
R. G. Munro1 ◽  
D Palmer ◽  
L Morrish
Keyword(s):  
Gear Tooth ◽  
Contact Region ◽  
Transmission Error ◽  
Spur Gears ◽  
Contact Ratio ◽  
Extended Contact ◽  
Tooth Stiffness ◽  
Simplifying Assumptions ◽  
Tooth Pair ◽  
Usual Problem

A method is presented that allows the accurate measurement of the tooth pair stiffness of a pair of spur gears. The method reveals the stiffness behaviour throughout the full length of the normal path of contact and also into the extended contact region when tooth corner contact occurs. The method makes use of the properties of transmission error plots for mean and alternating components over a range of tooth loads (Harris maps). It avoids the usual problem when measuring tooth deflections that deflections of other test rig components are difficult to eliminate. Also included are predicted Harris maps for a pair of high contact ratio spur gears, showing the effects of various simplifying assumptions, together with a measured map.

New Mathematical Model for the Form Factor of Involute Spur Gear’s Teeth

Tribology ◽  
2005 ◽  
Author(s):  
Aisman Quinones ◽  
Rafael Goytisolo ◽  
Jorge Moya ◽  
Roger Ocampo
Keyword(s):  
Form Factor ◽  
Factor Model ◽  
Gear Tooth ◽  
Radial Component ◽  
Physical Models ◽  
Theoretical Research ◽  
Correction Coefficient ◽  
Spur Gears ◽  
Fem Model ◽  
Lineal Regression

In this paper, a theoretical research is made on the influence of the friction force, the profile shift coefficient and the radial component of the normal force in the Form Factor applicable to the stress on spur gears’ teeth. A Gear’s FEM model was establish with the best approach to the real physical models, for the validation of the New Form Factor Model elaborated and then, the stress calculation in gear tooth root. Finally Using FEA and Multiple Lineal Regression, a new expression for the calculation of the stress concentration coefficient in the feet of the tooth, in function of the number of teeth and of the correction coefficient, was found.

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