The ways to enhance durability and bearing capacity of the open gear drum mills

2021 ◽  
Vol 15 (3) ◽  
pp. 87-94
Author(s):  
Borys Vynohradov ◽  
Veronika Karpenko ◽  
Olena Lahoshna ◽  
Kostiantyn Bas ◽  
Iryna Slovska
Keyword(s):  
Bearing Capacity ◽  
Load Distribution ◽  
Functional Relation ◽  
Operational Conditions ◽  
Gear Teeth ◽  
Factors Influencing ◽  
Working Surface ◽  
World Class ◽  
Gear Drives ◽  
Practical Implications

Purpose is substantiating ways to enhance durability and bearing capacity of open gears of ore-pulverizing drum mills as well as efficiency of engineering solutions concerning the increase in their unit power at the expense of drive improvement. Methods. Results of continual experiments and theoretical studies have been generalized as for the abrasion of working surfaces of open gear teeth of drum mills and factors influencing load distribution in terms of a tooth rim width. Findings. Comparative analysis between domestic mills and the best world-class products has been carried out. Ways of solving problems to design large-capacity mills with a gearbox drive have been demonstrated. Influence of hardness of working teeth surfaces on their durability has been evaluated quantitatively. The factors, governing load distribution in terms of tooth rim width, have been analyzed. Use of self-adjusting gear drives for open gears has been evaluated. Originality. Functional relation between stress-strain properties of working surface of teeth; the number of running-in modes, determined by operational conditions; and durability of open gear has been identified. The factors, influencing load distribution in terms of tooth rim width, have been considered. Practical implications. It has been shown that use of such open gears, where hardness of working surface of gear teeth is (500-600) H1B1 and that of a tooth rim one is (260-300) H2B2, makes it possible to provide almost wear-free operation. Moreover, it is the required condition for the performance of a tooth rim with two drive gears.

Load Distribution in Double Enveloping Worm Gears

1993 ◽  
Vol 115 (3) ◽  
pp. 496-501 ◽  
Author(s):  
V. Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Design Parameters ◽  
Distribution Factor ◽  
Axial Deformation ◽  
Gear Teeth ◽  
Worm Gears ◽  
New Type ◽  
Alignment Errors ◽  
Gear Drives

A method for the determination of load sharing among the instantaneously engaged worm threads and gear teeth of double enveloping worm gears and for the calculation of load distribution along their instantaneous contact lines is presented. The bending and shearing deflection of worm thread and gear tooth, the contact deformation, the axial deformation of worm body, and the manufacturing and alignment errors of worm and gear are included. The obtained system of integral equations is solved by using approximations and an iterative technique. The corresponding computer program is developed. By using this program, the load distribution in the classical and in a new type of double enveloping worm gear drives is calculated. The influence of design parameters on load distribution factor and on maximum tooth pressure is investigated and discussed.

scholarly journals Characteristics of Indoor Flood Fatalities: Evidence from Greece

2021 ◽  
Vol 13 (15) ◽  
pp. 8612
Author(s):  
Michalis Diakakis ◽  
Katerina Papagiannaki
Keyword(s):  
Building Material ◽  
Human Life ◽  
Older Individuals ◽  
Statistical Association ◽  
Flood Events ◽  
Building Collapse ◽  
Factors Influencing ◽  
Flooding Events ◽  
Practical Implications ◽  
Significant Statistical Association

Despite the important advances in flood forecasting and protection, floods remain one of the most lethal types of natural hazards. Previous works have explored several factors influencing the risks of flooding to human life and health. However, there is limited research and understanding on indoor flood fatalities and the circumstances under which they occur. This study explores victim-, building-, and situation-related characteristics in order to provide a better understanding of the conditions that lead to flood-related indoor deaths, exploiting a fatality database developed for Greece (1960–2020). The correlation analysis showed that indoor victims, compared with outdoor ones, tend to be older individuals, with high percentages of disabilities. A significant statistical association of the building material, roof type, and distance from the river with the building collapse was also found. The profile of the buildings in which flood fatality occurred was further compared with that of neighboring non-fatal buildings that were inhabited during the flood events. The statistical results indicated that the buildings with a fatality occurrence are mostly single-storey structures, made from masonry as the main building material. The findings have practical implications in risk communication and mitigation in terms of identifying the specific populations, circumstances, settings, and mechanisms that lead to dangerous indoor situations during flooding events.

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).

scholarly journals The Role of Gender and Situational Factors in Wine Consumption of Generation Y

2013 ◽  
Vol 8 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Jasmina Dlačić ◽  
Selma Kadić-Maglajlić
Keyword(s):  
Eastern Europe ◽  
Generation Y ◽  
Situational Factors ◽  
Wine Consumption ◽  
South Eastern ◽  
Factors Influencing ◽  
Research Findings ◽  
South Eastern Europe ◽  
Practical Implications

Abstract The purpose of this study is to analyze the factors influencing wine consumption of Generation Y consumers in the context of two countries from South-Eastern Europe (Bosnia -Herzegovina, and Croatia). Analysis reveals that self-expression, sociability, tradition and food are significant predictors of wine consumption. Multivariate regressions have been applied in order to explain the influences of the abovementioned factors on wine consumption. Research findings show that specific gender and situational differences exist in the wine consumption behaviour of Generation Y. This paper discusses theoretical, empirical and practical implications, and offers ideas for further research

scholarly journals Where Can Tourism-Led Growth and Economy-Driven Tourism Growth Occur?

2018 ◽  
Vol 58 (5) ◽  
pp. 760-773 ◽  
Author(s):  
Vera Shanshan Lin ◽  
Yang Yang ◽  
Gang Li
Keyword(s):  
Growth Patterns ◽  
International Tourism ◽  
Causal Relationships ◽  
Regional Economic ◽  
Empirical Results ◽  
Developed Economies ◽  
The Past ◽  
Factors Influencing ◽  
Probit Models ◽  
Practical Implications

In this study, we investigate the causal relationships between international tourism growth and regional economic expansion in China, and more importantly, disclose the factors determining the occurrence of these relationships. The empirical results reveal that 10 of 29 regions experienced tourism-led growth (TLG) during 1978 to 2013, whereas nine regions experienced economy-driven tourism growth (EDTG). Different from the past literature, this study uses Bayesian probit models to unveil the factors influencing these different growth patterns. Our results suggest that regions with less-developed economies, larger economic sizes, and covering larger geographic areas are more likely to experience TLG, and regions with less-developed economies are more likely to experience EDTG as well. Lastly, practical implications are provided.

scholarly journals Gear Tooth Stress Measurements of Two Helicopter Planetary Stages

1992 ◽  
Author(s):  
Timothy L. Krantz
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Nasa Lewis Research ◽  
Ring Gear ◽  
Gear Teeth ◽  
Load Variation ◽  
Planet Gear ◽  
Helicopter Main Rotor ◽  
Stress Variations ◽  
Root Location

Abstract Two versions of the planetary reduction stages from U.S. Army OH-58 helicopter main rotor transmissions were tested at the NASA Lewis Research Center. One sequential and one nonsequential planetary were tested. Sun gear and ring gear teeth strains were measured, and stresses were calculated from the strains. The alternating stress at the fillet of both the loaded and unloaded sides of the teeth and at the root of the sun gear teeth are reported. Typical stress variations as the gear tooth moves through the mesh are illustrated. At the tooth root location of the thin-rimmed sun gear, a significant stress was produced by a phenomenon other than the passing of a planet gear. The load variation among the planets was studied. Each planet produced its own distinctive load distribution on the ring and sun gears. The load variation was less for a three-planet, nonsequential design as compared to that of a four-planet, sequential design. The results reported enhance the data base for gear stress levels and provide data for the validation of analytical methods.

scholarly journals An Analysis of the Relationship between Victimization and Violent Behavior at School

2013 ◽  
Vol 16 ◽  
Author(s):  
Estefanía Estévez ◽  
Teresa I. Jiménez ◽  
David Moreno ◽  
Gonzalo Musitu
Keyword(s):  
School Violence ◽  
Structural Equation ◽  
Violent Behavior ◽  
School Context ◽  
Equation Modeling ◽  
Factors Influencing ◽  
Authority Figures ◽  
Modeling Techniques ◽  
The Relationship ◽  
Practical Implications

AbstractPrevious studies have identified two subgroups of school violence victims: submissive and aggressive. Submissive victims are characterized by their withdrawal in violent situations, while aggressive victims combine hostile behavior with victimization. This study focuses on the second subgroup and aims to analyze possible factors influencing the transition from passive victimization to involvement in aggressive behaviors within the school context. To test these relationships, 1319 adolescents between 12 and 16 years of age were recruited from seven secondary schools in various Spanish provinces. Structural equation modeling techniques were used to analyze the data. Results supported Emler’s theory, which posits that the victim’s helplessness in situations of intimidation, along with disappointment resulting from a lack of expected protection from adult authority figures, may result in adolescents searching and developing an antisocial and non-conformist reputation that helps them defend themselves against future attacks. Practical implications of these results are further discussed.

Evaluation of Influencing Factors on Great Britain‘S Export Values

2021 ◽  
Vol 18 (1) ◽  
pp. 59-69
Author(s):  
Milena Medineckiene ◽  
Viktorija Kirdaite
Keyword(s):  
Great Britain ◽  
Influencing Factors ◽  
Correlation Coefficients ◽  
Strong Relationship ◽  
Scientific Review ◽  
Factors Influencing ◽  
Labour Costs ◽  
Dependent Variables ◽  
Practical Implications ◽  
Regressive Analysis

Abstract Research purpose. The research aimed at identifying the main factors influencing export values in the region of Great Britain (GB) for the period of the last 30 years. Design / Methodology / Approach. In order to implement the investigation, the following tasks were intended: (1) To analyse scientific literature and mark out at least five non - dependent variables that impact export values of Great Britain. (2) Basing on findings, outlined in a scientific review, suggest or choose the methodology that is the most appropriate for this kind of tasks’ determination. (3) Collect the data for dependent and non-dependent variables (at least 30 samples). (4) Based on the presented methodology, determine the selected factors’ impact and make the statistical and economic analysis. The research was mainly done using quantitative analysis methods (descriptive, correlation, regressive analysis). Quantitative modelling and descriptive statistics methods are selected for investigation because they can suggest a different approach to analysing the factors influencing export values. Findings. Five non-dependent variables were marked out as factors influencing the export values in the selected region: gross domestic product (GDP); the number of employees in the region; amounts of cargo transportation; average salary in the region and labour costs. Calculation of the correlation coefficients showed that all independent variables were statistically significant. There is a very strong relationship between export values and GDP, employment, and labour costs. Originality / Value / Practical implications. The findings of this research can be applied in order to evaluate and determine the economic impact of the GB processes on the entire world, as Britain’s export values are among the top ten in the world. It is important to emphasise that the deeper analysis of the influencing factors of the volume of export in Great Britain showed an interrelation of these factors. So further investigation of this factor’s impact is essential.

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