FEM analysis of the load distribution over the face width of helical gear pairs considering deviations, misalignments and deformations

2019 ◽  
pp. 193-202
Author(s):  
A. Mihailidis ◽  
A. Psarros
Keyword(s):  
Load Distribution ◽  
Fem Analysis ◽  
Helical Gear ◽  
Face Width ◽  
The Face

Tooth Root Stresses of Helical Gear Pairs With Unequal and Offset Face Widths

2011 ◽  
Author(s):  
Carlos H. Wink
Keyword(s):  
Load Distribution ◽  
Element Model ◽  
Helical Gear ◽  
The Other ◽  
Gear Pair ◽  
Tooth Root ◽  
Pair Member ◽  
Face Width ◽  
The Face ◽  
Root Stress

In this study, tooth root stresses of helical gear pairs with different combinations of face width increase and offsets were analyzed. Contact face width was kept constant. The variables studied were face width and gear faces offset. The well-known LDP – Load Distribution Program was used to calculate tooth root stresses using a finite element model. The results presented show that the face width increase and offset have a significant influence on tooth root stresses. In some cases, increasing face width of one gear pair member resulted in significant increase of tooth root stress of the other member. For gear pairs with unequal and offset face widths, tooth root stresses were mostly affected when face widths were increased to the same direction of the contact line travel direction.

An Investigation of the Influence of Shaft Misalignments on Bending Stresses of Helical Gear With Lead Crown

2007 ◽  
Author(s):  
M. A. Hotait ◽  
D. Talbot ◽  
A. Kahraman
Keyword(s):  
Load Distribution ◽  
Helical Gear ◽  
Experimental Results ◽  
Distribution Model ◽  
Strain Gauges ◽  
Gear Teeth ◽  
Face Width ◽  
The Face ◽  
Bending Stresses ◽  
Different Levels

In this study, combined influence of shaft misalignments and gear lead crown on the load distribution and tooth bending stresses is investigated experimentally. A set of helical gear pairs having various amounts of lead crown was tested under loaded, low-speed conditions with varying amounts of tightly-controlled shaft misalignments. Gear teeth were instrumented through strips of strain gauges along the face width of gears at the tooth fillet region near the start of active profile. Variations of root strains along the face width were recorded for different levels of shaft misalignments and gear lead crown. At the end, the experimental results were correlated to the predictions of a gear load distribution model and recommendations were made on how much lead crown is optimal for a given misalignment condition.

Using variable modulus to modify a rack cutter and generate a gear pair

2022 ◽  
pp. 095440622110617
Author(s):  
Yang Hsueh-Cheng ◽  
Zhong-Wei Huang
Keyword(s):  
Helical Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Parabolic Profile ◽  
Face Width ◽  
Variable Modulus ◽  
The Face ◽  
Helical Gear Pair ◽  
Assembly Error

In this paper, two normal imaginary helical rack cutters were first established. One of these cutters is a skewed-rack cutter with an asymmetrical straight edge. The other is a rack cutter with an asymmetric parabolic profile. Second, the gear’s tooth surface of the asymmetric parabolic rack cutter is modified to be barrel-shaped based on a variable modulus. The tooth thickness of the gear is gradually reduced along the face width of the tooth from the middle of the tooth surface. Then the coordinate relationship between the gears’ blanks and the imaginary helical rack cutters was established. Through the differential geometry, crowned and uncrowned helical gear pairs were generated. Because of human factors, when the gear pair is installed, it is easy to cause the gear pair edge contact. It is necessary to add artificial assembly error settings through the tooth contact analysis to investigate the kinematic errors and contact conditions of the crowned and uncrowned helical gear pair. The mathematical models and analysis methods proposed for the crowned imaginary rack cutter using variable modulus should be useful for the design and production of double crowned helical gears with asymmetric parabolic teeth.

Experiments on Root Stresses of Helical Gears With Lead Crown and Misalignments

2008 ◽  
Vol 130 (7) ◽  
Author(s):  
M. Hotait ◽  
A. Kahraman
Keyword(s):  
Helical Gear ◽  
Strain Gages ◽  
Helical Gears ◽  
Gear Teeth ◽  
Face Width ◽  
The Face ◽  
Bending Stresses ◽  
Contact Models ◽  
Gear Contact ◽  
Different Levels

In this study, the results of an experimental parametric study of the combined influence of shaft misalignments and gear lead modifications on the load distribution and tooth bending stresses of helical gear pairs are presented. A set of helical gear pairs having various amounts of total lead crown was operated under loaded, low-speed conditions with varying amounts of tightly controlled shaft misalignments. Gear teeth were instrumented through strips of strain gages along the face width of gears at the tooth fillet region at a roll angle that is near the start of the active profile. Variations of root strains along the face width were quantified for different levels of shaft misalignments and gear lead crown. The results presented demonstrate the direct link between the lead crown and gear misalignments as well as the effectiveness of the lead crown in preventing edge loading conditions due to misalignment. The results presented here form a database that should be available for a validation of gear contact models in terms of their ability to simulate misalignments.

A Methodology to Experimentally Investigate the Impact of Wobble Errors on the Contact Pattern and Static Transmission Error of Helical Gear Pairs

2019 ◽  
Author(s):  
Michael Benatar ◽  
Michael Handschuh ◽  
Ahmet Kahraman ◽  
David Talbot
Keyword(s):  
Transmission Error ◽  
Helical Gear ◽  
Experimental Results ◽  
Gear Pair ◽  
Contact Pattern ◽  
Gear Mesh ◽  
Face Width ◽  
The Face ◽  
Static Transmission Error ◽  
The Impact

Abstract For a gear pair, both the contact pattern and the transmission error (TE) significantly impact durability and fatigue life. Design and manufacturing processes are often aimed at improving the contact pattern and reducing the overall TE. Other errors, such as runout and wobble, are often induced during the installation of power transmission systems, and they can alter the contact pattern and TE of an otherwise well-designed gear pair. This study provides a methodology to experimentally investigate the impact of wobble errors on the contact pattern and static transmission error (STE) of helical gears. It first provides a description of the modifications to an existing test machine. Next, it describes the gear specifications, preliminary testing matrix, data acquisition and processing procedure, as well as the experimental results obtained with regards to both the contact pattern and STE. The following are observed while describing the experimental results. For a test with no wobble and no runout, the contact pattern remains the same at every rotational position. However, by introducing even a small amount of wobble, the contact will shift from one side of the face width of the gear to the opposite side of the face width of the gear within one revolution. Introduction of wobble may increase the STE and sideband activity around gear mesh harmonics, especially as torque increases. Yet the modest increases in STE and sideband activity seen with the introduction of wobble are not enough to make definitive conclusions. The feasibility of the modified test setup has been demonstrated, and preliminary results have been presented. However, additional data collection should be completed in order to study the impact of runout and wobble on both spur and helical gear pairs with various microgeometry modifications and manufacturing errors.

scholarly journals Contact Stresses and Bending stresses for Worm & Helical Gear

2019 ◽  
Vol 8 (4) ◽  
pp. 11326-11328
Keyword(s):  
Contact Stress ◽  
Applied Load ◽  
Gear Tooth ◽  
Helical Gear ◽  
Contact Stresses ◽  
Bending Stress ◽  
Surface Strength ◽  
Face Width ◽  
The Face ◽  
Bending Stresses

Surface Strength of the gear tooth depends on the contact stress and the bending stress caused due to the applied load on the tip of its gear tooth. Analysis has become popular in decreasing the failures. Fatigue causes in the root bending stress and Surface indentation causes in the contact stress. Then modified Lewis beam strength is used for bending stress and the AGMA method is used for contact stresses by varying the face width. Analytical results are based on Lewis formula and the theoretical values were calculated by AGMA standard so the results were validated.

Three Dimensional Numerical Analyses of Bridge Piled-Raft Foundation under Riverbed Erosion

2012 ◽  
Vol 178-181 ◽  
pp. 2373-2377 ◽  
Author(s):  
Wen Tsung Liu ◽  
Yi Yi Li
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Bridge Piers ◽  
Piled Raft Foundation ◽  
River Erosion ◽  
Dimensional Finite Element ◽  
The Face ◽  
Three Dimensional Finite Element

From the 921 earthquake to the major typhoons, including the Morakot typhoon, they damaged original landscape of rivers in Taiwan. In recent years, it alleged that abutment bridge exposed to the most serious security problems. Because of bridge piers in addition to the face of long-term river erosion, the flood on the pier will produce localized erosion near the bridge. The pier will be due to inadequate bearing capacity, resulting in subsidence, displacement, bridge version accompanied by tilting and even caving. The river erosion of soil around the piers deposits and production of contraction will often reduce the bearing capacity. Therefore, how to accurately estimate the scour depth, calculate piers to withstand water impact and analyses its stability for preventing injuries in the first place is the current pressing issues. In this study, three-dimensional finite element method (FEM) analysis program Plaxis 3D foundation is used. Polaris second bridge is selected for analysis. Based on local scouring of the model and various numerical variable conditions, the parameter of bridge pier is studied.

scholarly journals Face morphology of brazilian and peruvian populations: analysis of proportion and linear measurement indexes

2017 ◽  
Vol 20 (3) ◽  
Author(s):  
Elaine Cristina Sousa Dos Santos ◽  
Diego Jesus Bradariz Pimentel ◽  
Laís Lopes Machado De Matos ◽  
Laís Valencise Magri ◽  
Ana Maria Bettoni Rodrigues Da Silva ◽  
...  
Keyword(s):  
Latin American ◽  
Linear Measurement ◽  
Linear Measurements ◽  
3D Images ◽  
Brazilian Sample ◽  
Face Width ◽  
The Face ◽  
Mouth Width ◽  
3D Stereophotogrammetry ◽  
Face Morphology

<p><strong>Objective: </strong>To compare the proportion and linear measurement indexes between Brazilian and Peruvian population through 3D stereophotogrammetry and to stablish the face profile of these two Latin American populations. <strong>Material and Methods: </strong>40 volunteers (Brazilian n=21– 10 males and 11 females; Peruvian n=19 – 8 males and 11 females) aged between 18 and 40 years (mean of 28.7±9.1) had landmarks marked on the face. Then, 3D images were obtained (VECTRA M3) and the indexes of proportion and linear measurement (face, nose, and lips) were calculated. The data were statistically analyzed by One-Way ANOVA (p&lt;0.05). <strong>Results: </strong>The proportion indexes did not reveal marked differences either between the studied populations or genders (p&gt;0.05). The following linear measurements showed intergroup statistically significant differences: face width and height, nose width and height, upper facial height, mouth width, protrusion of the nose tip (p&lt;0.05). The Brazilian females showed the smallest significant differences. <strong>Conclusions: </strong>Despite the different ethnic compositions, the Brazilian and Peruvian populations did not differ regarding the proportions of the face, nose, and lips. The differences observed in Brazilian females may be related to gender and/or to the Caucasian heritage of the Brazilian sample.</p><p><strong>Keywords</strong></p><p>Photogrammetry; Face; Tridimensional Image.<strong></strong></p>

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