Analysis of Tooth Surface Distress Using AGMA 925 and Numerical Load Distribution Methods

2003 ◽  
Author(s):  
Andrea Piazza ◽  
Gabriele Bellino
Keyword(s):  
Experimental Data ◽  
Load Distribution ◽  
Present Knowledge ◽  
Tooth Surface ◽  
Spur Gears ◽  
Design Review ◽  
Helical Gears ◽  
Classical Test ◽  
Surface Distress ◽  
The One

The AGMA document 925 is an important step toward the standardisation of the present knowledge of the surface distress mechanisms; specifically it provides a careful look onto two important phenomena as scuffing and wear on gears employing a wide set of experimental data provided by literature and AGMA members; but since the load distribution is calculated using simplified methods the obtained results may be limited to gear designs whose load distribution is similar to the one(s) of the test gearset(s) where the above data was collected, i.e. spur gears, mostly accurately designed to scuff and to test lubricants. The work summarizes the different effects of applying the cited document methodology using simplified load distribution and most sophisticated one(s) on classical test gears for lubricants and on helical designs. It is shown that using more sophisticated load distribution methods the results on helical gears may be strongly different with respect of simplified methods and may suggest, in some cases, a design review.

Revisiting Generation and Meshing Properties of Beveloid Gears

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Alessio Artoni ◽  
Massimo Guiggiani
Keyword(s):  
Tooth Surface ◽  
Generation Process ◽  
Spur Gears ◽  
Helical Gears ◽  
Additional Degree ◽  
Beveloid Gears ◽  
Fixed Space ◽  
Fixed Axis ◽  
The One ◽  
Special Case

The teeth of ordinary spur and helical gears are generated by a (virtual) rack provided with planar generating surfaces. The resulting tooth surface shapes are a circle-involute cylinder in the case of spur gears, and a circle-involute helicoid for helical gears. Advantages associated with involute geometry are well known. Beveloid gears are often regarded as a generalization of involute cylindrical gears involving one additional degree-of-freedom, in that the midplane of their (virtual) generating rack is inclined with respect to the axis of the gear being generated. A peculiarity of their generation process is that the motion of the generating planar surface, seen from the fixed space, is a rectilinear translation (while the gear blank is rotated about a fixed axis); the component of such translation that is orthogonal to the generating plane is the one that ultimately dictates the shape of the generated, envelope surface. Starting from this basic fact, we set out to revisit this type of generation-by-envelope process and to profitably use it to explore peculiar design layouts, in particular for the case of motion transmission between skew axes (and intersecting axes as a special case). Analytical derivations demonstrate the possibility of involute helicoid profiles (beveloids) transmitting motion between skew axes through line contact and, perhaps more importantly, they lead to the derivation of designs featuring insensitivity of the transmission ratio to all misalignments within relatively large limits. The theoretical developments are confirmed by various numerical examples.

The Compliance of Solid, Wide-Faced Spur Gears

1990 ◽  
Vol 112 (4) ◽  
pp. 590-595 ◽  
Author(s):  
J. H. Steward
Keyword(s):  
Experimental Data ◽  
Contact Line ◽  
Load Distribution ◽  
3D Model ◽  
Spur Gear ◽  
Point Load ◽  
Spur Gears ◽  
Line Load ◽  
Gear Teeth ◽  
Theoretical Results

In this paper, the requirements for an accurate 3D model of the tooth contact-line load distribution in real spur gears are summarized. The theoretical results (obtained by F.E.M.) for the point load compliance of wide-faced spur gear teeth are set out. These values compare well with experimental data obtained from tests on a large spur gear (18 mm module, 18 teeth).

Revisiting Plane-Generated Gear Tooth Surfaces: A Novel Design Perspective

2015 ◽  
Author(s):  
Alessio Artoni ◽  
Massimo Guiggiani
Keyword(s):  
Gear Tooth ◽  
Transmission Function ◽  
Tooth Surface ◽  
Generation Process ◽  
Noise Emission ◽  
Helical Gears ◽  
Beveloid Gears ◽  
Tooth Surfaces ◽  
Involute Gears ◽  
The One

The teeth of ordinary spur and helical gears are generated by a (virtual) rack provided with planar generating surfaces. The resulting tooth surface shapes are a circle-involute cylinder in the case of spur gears, and a circle-involute helicoid for helical gears. Advantages associated with involute geometry are well known: in particular, the motion transmission function is insensitive to center distance variations, and contact lines (or points, when a corrective surface mismatch is applied) evolve along a fixed plane of action, thereby reducing vibrations and noise emission. As a result, involute gears are easier to manufacture and assemble than non-involute gears, and silent to operate. A peculiarity of their generation process is that the motion of the generating planar surface, seen from the fixed space, is a rectilinear translation (while the gear blank is rotated about a fixed axis): the component of such translation that is orthogonal to the generating plane is the one that ultimately dictates the shape of the generated, envelope surface. Starting from this basic fact, we set out to investigate this type of generation-by-envelope process and to profitably use it to explore new potential design layouts. In particular, with some similarity to the basic principles underlying conical involute (or Beveloid) gears, but within a broader scope, we propose a generalization of these concepts to the case of involute surfaces for motion transmission between skew axes (and intersecting axes as a special case). Analytical derivations demonstrate the theoretical possibility of involute profiles transmitting motion between skew axes through line contact and, perihaps more importantly, they lead to apparently novel geometric designs featuring insensitivity of transmission ratio to all misalignments within relatively large limits. The theoretical developments are confirmed by various numerical examples.

Profile Modifications for Minimum Static Transmission Error in Cylindrical Gears

1998 ◽  
Author(s):  
Isaias Regalado ◽  
Donald R. Houser
Keyword(s):  
Load Distribution ◽  
Strong Relationship ◽  
Transmission Error ◽  
Gear Ratio ◽  
Spur Gears ◽  
Helical Gears ◽  
Involute Gears ◽  
Theoretical Advantage ◽  
Static Transmission Error ◽  
The Common

Abstract The theoretical advantage of conjugate action in involute gears is lost due to the deflection of the teeth under load and due to manufacturing and assembling errors. These factors produce instantaneous variations in the gear ratio commonly referred to as transmission error. The transmission error has been proven to have a strong relationship with the noise emitted by the transmission. In order to reduce the transmission error, the contacting surfaces of the gears are modified to compensate for the deflections and errors. These modifications may be performed in the direction of the profile, the lead or in a more general sense it may be topographical (defined point by point). This paper describes a non-iterative procedure for the calculation of the modifications for minimum transmission error based on a predefined load distribution. The results presented agree with the common practice for spur gears of tip relief in the direction of the profile and crowning in the direction of the lead, but for helical gears the need for a more complicated modification is observed.

A Tooth Contact Analysis Model for Crossed Axis Helical Gears Under Load

1996 ◽  
Author(s):  
Y. Zhang ◽  
Z. Fang
Keyword(s):  
Load Distribution ◽  
Surface Deformation ◽  
Principal Direction ◽  
Tooth Surface ◽  
Analysis Model ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Helical Gears ◽  
Gear Mesh ◽  
Tooth Surfaces

Abstract This paper presents an approach for the analysis of tooth contact and load distribution of helical gears with crossed axis. The approach is based on a tooth contact model that accommodates the influence of tooth profile modifications, gear manufacturing errors and tooth surface deformation on gear mesh quality. In the approach, the tooth contact load is assumed to be distributed along the tooth surface line that coincides with the relative principal direction of the contacting tooth surfaces. The model in this paper provides a quantitative analysis on gear transmission errors, contact patterns and the load distribution of helical gears with crossed axes when the tooth surfaces are deformed under load. As a numerical example, the contact of a pair of helical gears with a small crossing angle is analyzed by the computer program that implements the approach.

Revision of Tooth Surface in Order to Compensate the Load Deviation of the Plastic Gears

2010 ◽  
Vol 139-141 ◽  
pp. 1084-1087
Author(s):  
Hu Ran Liu
Keyword(s):  
Load Distribution ◽  
Theoretical Basis ◽  
Order Differential Equation ◽  
Tooth Surface ◽  
Surface Load ◽  
Spur Gears ◽  
Circular Arc ◽  
Fundamental Equations ◽  
Plastic Gears ◽  
Torsion Deformation

Based on the torsion deformation the gear body and the contact deformation of tooth surface, the fundamental equations of load of the gear was presented, thus established the theoretical basis of the load derivation of the gearing. In this paper, the torsion deformation of the circular arc gears is analyzed first. Then the second order differential equation for the tooth surface load distribution of the involutes gears has been deduced. The equation for the load derivation of the spur gears is presented while the errors of original tooth surface are under consideration. Revision of tooth surface in order to compensate the load deviation of the plastic gears is presented in this paper.

Shaping Principle in Hobbing and Analysis on Errors of Involute Gear Tooth Surfaces

2011 ◽  
Vol 189-193 ◽  
pp. 4173-4176 ◽  
Author(s):  
Wen Long Li ◽  
Li Wei ◽  
Shao Jun He
Keyword(s):  
Gear Tooth ◽  
Tooth Surface ◽  
Spur Gears ◽  
Helical Surface ◽  
Helical Gears ◽  
Surface Errors ◽  
Error Characteristics ◽  
Involute Gear ◽  
Characteristic Lines ◽  
Tooth Surfaces

An involute helical surface is one of the surfaces widely used in engineering. There are four characteristics lines ( involute, helix, straight generatrix, pathofcontact) on it. On the basis of characteristic lines, the shaping principle in hobbing is studied, the error characteristics and their interrelations are analyzed. The analysis formula of involute gear tooth surface errors is given for spur gears and helical gears.

scholarly journals Unbinding of Hyaluronan Accelerates the Enzymatic Activity of Bee Hyaluronidase

2011 ◽  
Vol 286 (41) ◽  
pp. 35699-35707 ◽  
Author(s):  
Attila Iliás ◽  
Károly Liliom ◽  
Brigitte Greiderer-Kleinlercher ◽  
Stephan Reitinger ◽  
Günter Lepperdinger
Keyword(s):  
Experimental Data ◽  
Quartz Crystal ◽  
Surface Loop ◽  
X Ray ◽  
Site Model ◽  
Substrate Interaction ◽  
Close Proximity ◽  
Binding Groove ◽  
The One ◽  
Best Fit

Hyaluronan (HA), a polymeric glycosaminoglycan ubiquitously present in higher animals, is hydrolyzed by hyaluronidases (HAases). Here, we used bee HAase as a model enzyme to study the HA-HAase interaction. Located in close proximity to the active center, a bulky surface loop, which appears to obstruct one end of the substrate binding groove, was found to be functionally involved in HA turnover. To better understand kinetic changes in substrate interaction, binding of high molecular weight HA to catalytically inactive HAase was monitored by means of quartz crystal microbalance technology. Replacement of the delimiting loop by a tetrapeptide interconnection increased the affinity for HA up to 100-fold, with a KD below 1 nm being the highest affinity among HA-binding proteins surveyed so far. The experimental data of HA-HAase interaction were further validated showing best fit to the theoretically proposed sequential two-site model. Besides the one, which had been shown previously in course of x-ray structure determination, a previously unrecognized binding site works in conjunction with an unbinding loop that facilitates liberation of hydrolyzed HA.

A Spray-Droplet Model for Diesel Combustion

1969 ◽  
Vol 184 (10) ◽  
pp. 28-35 ◽  
Author(s):  
J. Shipinski ◽  
P. S. Myers ◽  
O. A. Uyehara
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Heat Release ◽  
Engine Speed ◽  
Chamber Pressure ◽  
Gas Temperature ◽  
Single Droplet ◽  
Burning Rates ◽  
Burning Model ◽  
The One

A spray-burning model (based on single-droplet theory) for heat release in a diesel engine is presented. Comparison of computations using this model and experimental data from an operating diesel engine indicate that heat release rates are not adequately represented by single-droplet burning rates. A new concept is proposed, i.e. a burning coefficient for a fuel spray. Comparisons between computations and experimental data indicate that the numerical value of this coefficient is nearly independent of engine speed and combustion-chamber pressure. However, the instantaneous value of the spray burning coefficient is approximately proportional to the instantaneous mass-averaged cylinder gas temperature to the one-third power.

Analytical Model of the Efficiency of Spur Gears: Study of the Influence of the Design Parameters

2011 ◽  
Author(s):  
Miguel Pleguezuelos ◽  
Jose´ I. Pedrero ◽  
Miryam B. Sa´nchez
Keyword(s):  
Load Distribution ◽  
Gear Ratio ◽  
Design Parameters ◽  
Spur Gears ◽  
Transmitted Power ◽  
Power Losses ◽  
Contact Ratio ◽  
Complete Study ◽  
Uniform Model ◽  
Analytical Expressions

An analytic model to compute the efficiency of spur gears has been developed. It is based on the application of a non-uniform model of load distribution obtained from the minimum elastic potential criterion and a simplified non-uniform model of the friction coefficient along the path of contact. Both conventional and high transverse contact ratio spur gears have been considered. Analytical expressions for the power losses due to friction, for the transmitted power and for the efficiency are presented. From this model, a complete study of the influence of some design parameters (as the number of teeth, the gear ratio, the pressure angle, the addendum modification coefficient, etc.) on the efficiency is presented.

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