Approximate Method for the Determination of the Bending Strength Geometry Factor for External Spur and Helical Gear Teeth

1999 ◽  
Vol 122 (3) ◽  
pp. 331-336 ◽  
Author(s):  
J. I. Pedrero ◽  
A. Fuentes ◽  
M. Estrems
Keyword(s):  
Bending Strength ◽  
Helical Gear ◽  
Critical Section ◽  
Approximate Determination ◽  
Tool Geometry ◽  
Geometry Factor ◽  
Gear Teeth ◽  
Iterative Procedures ◽  
Center Distance

The methods currently available for the determination of the AGMA J-factor require iterative procedures in order to compute the value of the critical section parameter, which is necessary to compute the tooth thickness at the critical section and the height of the Lewis parabola. This paper presents an approximate, non-iterative method for the determination of the AGMA J-factor for involute, external gear teeth, which is based on the approximate determination of the critical section. The method is valid for any tool geometry, including rack-type or pinion-type generation, and considers tool offsets, center distance modifications and backlash. [S1050-0472(00)00903-X]

A Reconsideration of the Geometry Factor for the Standard and Profile Shifted Teeth

1989 ◽  
Vol 111 (3) ◽  
pp. 402-413 ◽  
Author(s):  
J. H. Kuang ◽  
Y. T. Yang
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Stress Concentration Factor ◽  
Empirical Equation ◽  
Design Parameters ◽  
Spur Gears ◽  
Geometry Factor ◽  
Gear Teeth ◽  
Semi Empirical

A semi-empirical equation for the determination of the stress concentration factor for spur gears is introduced. The effects of some design parameters such as fillet radii of rack cutters, teeth number, and profile shifting factor, on the stress distribution at the fillets of gear teeth are investigated. Values of the modified geometry factors for the standard and profile shifted teeth are also derived. It is hoped that the present investigation may yield a more accurate prediction of the localized stresses at tooth fillets than the results thus far available.

The Determination of the Lewis Form Factor and the AGMA Geometry Factor J for External Spur Gear Teeth

1982 ◽  
Vol 104 (1) ◽  
pp. 148-158 ◽  
Author(s):  
R. G. Mitchiner ◽  
H. H. Mabie
Keyword(s):  
Form Factor ◽  
Spur Gear ◽  
Constant Stress ◽  
Direct Approach ◽  
Center Line ◽  
Geometry Factor ◽  
Gear Teeth ◽  
Definition Of ◽  
Line Intercept

This paper presents a simple and direct approach to the problem of the definition of the root profile for standard and nonstandard external spur gear teeth. Equations are developed for the location of the tooth center-line intercept at the constant-stress parabola. Also, the expression for the location of the point of tangency of the parabola with the root trochoid is given as well as the derivative of this expression. The AGMA Standards present charts of geometry factors, but the method by which these factors were determined is graphical and in some instances is not sufficiently accurate nor convenient to use. Although other investigators have considered this problem, their methods are either graphical or very complicated analytically. This treatment of the problem has been developed because it is not available in the open literature. Tables and charts are given for both Y and J factors for many profile variations.

Determination of the effective path of contact of undercut involute gear teeth

2004 ◽  
Vol 218 (7) ◽  
pp. 751-760 ◽  
Author(s):  
J I Pedrero ◽  
M Artés ◽  
C García-Masiá
Keyword(s):  
Accurate Determination ◽  
Approximate Equation ◽  
Helical Gear ◽  
Computer Applications ◽  
Contact Ratio ◽  
Gear Teeth ◽  
Involute Gear ◽  
Stress Levels ◽  
Effective Path

An approximate equation for accurate determination of the inner point of the involute profile of undercut spur and helical gear teeth is presented. This point may have influence on the effective path of contact and consequently on the contact ratio, the length of the path of contact and the stress levels, which should be taken into account for calculation and standardization purposes. Since the equation is valid for any tool proportions, it is very efficient for computer applications.

Application of the criterion for total wear of the surface layer of gear teeth in determining helical gear geometric parameters

2020 ◽  
pp. 20-27
Author(s):  
A.G. Popovich
Keyword(s):  
Surface Layer ◽  
Layer Thickness ◽  
Helical Gear ◽  
Operating Period ◽  
Wear Process ◽  
Wear Rates ◽  
Gear Teeth ◽  
Total Wear ◽  
Gear Wheels

Formulas for determination of worn-out layer thickness sum on the mating rapidly wearing areas of teeth active surfaces of driving and driven helical gear wheels are deduced on the basis of involute gearing theory considering the laws of wear process. An equation of the linkage between such values of basic rack shift coefficients for the helical gear wheels which minimize the greater sum of wear rates on these areas is derived. Solution of this equation by numerical method for the helical gear having standard distance between axes allows determining these values of shift coefficients with which operating period of this gear until achievement of the permissible worn-out layer thickness sum on the mentioned areas will be maximal. Keywords: involute helical gear, displacement coefficient, producing rail, specific slip, contact stress, wear thickness. [email protected]

scholarly journals Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3979
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Karolina Miedzińska ◽  
Krzysztof Strzelec
Keyword(s):  
Flame Retardants ◽  
Elevated Temperatures ◽  
Bending Strength ◽  
Reaction System ◽  
Fire Retardant ◽  
Polyurethane Foams ◽  
Polymerization Reaction ◽  
Three Point Bending ◽  
One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

Sign in / Sign up

Export Citation Format

Share Document