scholarly journals Bidirectional modification of gears in the generalized theory of meshing

2019 ◽  
Vol 287 ◽  
pp. 01006
Author(s):  
Ognyan Alipiiev
Keyword(s):  
New Classification ◽  
Gear Drive ◽  
Involute Gear ◽  
Different Types ◽  
Involute Gears ◽  
Proposed Modification ◽  
Gear Drives ◽  
Tangential Directions

An important part of “Generalized theory”, developed by the author of this article, is the “bidirectional modification” of involute gears. The main point of the proposed modification is that together with the traditional “radial modification” of the basic rack, an additional “tangential modification” of the side profiles of the rack-cutters is introduced. As a result, the area of possible existence of involute gear drives in the generalized theory is considerably extended. Based on the bidirectional modification, a new classification of involute gears at their meshing with a rack cutter is proposed. The classification is characterized by a significant variety, which is composed of thirteen different types of gears: a zero gear; two radially modified gears; two tangentially modified gears and eight two-way modified gears. Based on the bidirectional modification in radial and tangential directions, a new classification of the involute gear drives is proposed. The classification is composed of sixteen different types of gear drives: a zero gear drive, three equally-modified gear drives; two balanced gear drives; five positive gear drives and five negative gear drives.

Gearing principle and geometric design of conical involute gear pairs with crossed axes

2004 ◽  
Vol 218 (12) ◽  
pp. 1517-1526 ◽  
Author(s):  
J He ◽  
X Wu ◽  
Y Cui
Keyword(s):  
Helix Angle ◽  
Design Methods ◽  
Reference Plane ◽  
Gear Drive ◽  
Involute Gear ◽  
Involute Gears ◽  
Crossed Axes ◽  
Gear Drives ◽  
Design And Manufacture ◽  
Reverse Methods

A group of formulae for the geometric parameters, such as the gear mounting distance, crossed-axes angle, centre distance and helix angle of the tooth projection on the reference plane of a reference rack, of a crossed-axes gear drive of different arrangements are derived based on the analysis of the spatial mesh relationship between conjugate gears and their reference rack. A set of geometrical design methods for conical involute gear pairs with crossed axes (non-intersecting and non-parallel axes) is presented. The formulae can be applied not only to all of the possible independent forms of crossed-axes gear drives but also to the case of gearing with parallel axes and intersecting axes. The design methods consist of two parts, the sequential and the reverse methods. The former is used to determine the mounting dimensions when the basic dimensions of a pair of conical involute gears are given, while the latter is used to determine basic dimensions of a pair of gears when the mounting dimensions are known. The formulae and the methods are verified through the design and manufacture of a set of testing gears.

Effect of tooth waist order parameters of double involute gears on lubrication performance of gear drive

2016 ◽  
Vol 68 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Zhimin Fan ◽  
Wanfeng Zhou ◽  
Ruixue Wang ◽  
Na Wang
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Reference Value ◽  
Tooth Profile ◽  
Order Parameters ◽  
Content Type ◽  
Oil Film ◽  
Gear Drive ◽  
Involute Gear ◽  
Lubrication Performance ◽  
Involute Gears

Purpose The purpose of this paper is to derive a new lubrication model of double involute gears drive and study the effect of the tooth waist order parameters of double involute gears on lubrication performance. Design/methodology/approach The new lubrication model of double involute gears drive was established according to the meshing characteristics of double involute gears drive and the finite length line contact elastohydrodynamic lubrication theory. Numerical calculation of the lubrication model of gear drive was conducted using the multigrid method. Findings The results show that the oil film necking phenomenon and the oil film pressure peak emerged at the tooth waist order area and the tooth profile ends, and when compared with involute gear, the lubrication performance at the tooth waist order area is better than that at the tooth profile ends. The effect of tooth waist order parameters on lubrication performance at the tooth waist order area was greater than that at other areas. Originality/value This research will promote the application of the double involute gear as soon as possible, and it has the reference value for other types of gears.

scholarly journals Problematics of forming the political space of Ukraine and the EU

2016 ◽  
pp. 32-43
Author(s):  
Bogdan Ferens
Keyword(s):  
European Union ◽  
Political Parties ◽  
Political System ◽  
The Political ◽  
Political Space ◽  
Policy Space ◽  
New Classification ◽  
Different Types ◽  
The Eu

The article is devoted to the issue of political space forming of contemporary Ukraine and European Union. The paper proposes a new classification of the political parties which are represented in Ukraine. It was determined by using different types of analysis the concept of “policy space” and its application in contemporary political science, main trends and relationships that directly affect the integration of Ukraine’s political system into the EU political space, importance of inter-party cooperation in the process of European integration.

scholarly journals Genesis and Nature of Moral and Legal Norms. Leon Petrażycki’s Naturalistic Solution

Studia Humana ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 39-52 ◽  
Author(s):  
Andrzej Dąbrowski
Keyword(s):  
Cognitive Processes ◽  
Fundamental Difference ◽  
Scientific Methodology ◽  
Moral Norms ◽  
Emotional Experiences ◽  
New Classification ◽  
Legal Norms ◽  
Different Types ◽  
Over Time

Abstract The aim of the paper is to examine the nature of moral and legal norms in a broader context: first, taking into account logical and methodological assumptions, second, in the perspective of psychology of emotions and legal policy. The basic subject of the research carried out by Leon Petrażycki was represented by law. Originally, it had a psychological character, not an objective, eternal, and unchanging one. To fully understand the genesis and nature of morality and law, Petrażycki addressed the study of mental phenomena, especially emotional experiences. First, however, he developed appropriate rules of logic and scientific methodology. Then he developed a new classification of mental phenomena, among which the fundamental role is played by bilateral (passive-active) emotions. At some stage, emotions begin to cooperate with cognitive processes, first of all with imaginations. Imaginations of acts, such as theft, betrayal, murder, can cause repulsive emotions, and type imaginations, such as truthfulness, charity, justice can evoke apulsive emotions. On the basis of such associations, judgments are created over time, the content of which becomes a basis for fundamental rules of conduct, that is, for norms. There are two fundamentally different types of norms: moral norms and legal norms. The norms of the first type are imperative and represent the nature of validity (they are obeyed), while the norms of the second type are imperative-attributive and they also always entitle someone to something, i.e. they give someone a right. This division determines a fundamental difference between morality and law.

Novel Torus-Involute Gear Transmission

2012 ◽  
Vol 155-156 ◽  
pp. 1050-1055
Author(s):  
Lei Liu ◽  
Zhu Qing Huang
Keyword(s):  
Design Method ◽  
Gear Transmission ◽  
Transmission Ratio ◽  
Gear Drive ◽  
Involute Gear ◽  
Involute Gears ◽  
Shaft Angle

A novel torus-involute gear transmission is presented in this paper. There are two types of tooth profiles for torus-involute gears: convex tooth and concave tooth. Torus-involute gears are non-sensitive to axial misalignments and allow variable shaft angle without meshing interference. Based on revealing of essence for tooth profiles, introducing the parameter t and discretizing this type of gear into tiny linear continuous corrected gears, a design method is proposed. To testify whether the transmission ratio of torus-involute gear transmission is constant, simulation is implemented in commercial codes ADAMS. The computed results show that this novel gear drive can achieve a constant transmission ratio with variable shaft angle.

scholarly journals Polysemy in Linguistic Terminological Systems Based on the Analysis of French Linguistic Terms

2016 ◽  
Vol 2 (2) ◽  
pp. 61-67
Author(s):  
Denis Zolotukhin
Keyword(s):  
Term Structure ◽  
Semantic Structure ◽  
Abstract Model ◽  
Linguistic Terms ◽  
New Classification ◽  
Linguistic Research ◽  
Different Types ◽  
Negative Characteristic ◽  
The Given

The article reports on the features of polysemy in French terminological systems of linguistics at inter-system and intra-system levels. The existing studies concerning terminological semantics allow pointing out two aspects of the term structure: a semantic structure representing a complex of meanings, and a structure of the terminological meaning representing a complex of semes. The first aspect supposes the analysis of terminological polysemy regarded as a negative characteristic of terms. According to the second aspect some particularities of denotative and significative levels and their correlation to scientific concepts can be analyzed. In the given study the component analysis of the definitions of French terms – such as ‘sémantème’, ‘mot’ and ‘signe’ – reveals different types of polysemy and terminological variation. The analysis of semantic structures of these terms shows that terminological deviations are caused by objective differences at significative and denotative levels of the meaning as well as by the subjective use of occasional contexts of terms in linguistic research. The suggested results allow constructing a new classification of meaning relations of linguistic terms. Each type of relations is correlated to different elements of the term structure. The hierarchy of these elements is embodied into an abstract model that can be applied for the analysis of any term of the modern linguistic terminology.

scholarly journals Worm Gear Drives with Improved Kinematic Accuracy

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7825
Author(s):  
Wojciech Kacalak ◽  
Maciej Majewski ◽  
Zbigniew Budniak ◽  
Jacek Ponomarenkow
Keyword(s):  
Load Capacity ◽  
Worm Gear ◽  
Central Section ◽  
Positioning Systems ◽  
Kinematic Accuracy ◽  
Gear Drive ◽  
Fold Reduction ◽  
Different Types ◽  
Gear Drives ◽  
High Degree

This paper presents the fundamentals of the design and applications of new worm gear drive solutions, which enable the minimisation of backlash and are characterised by higher kinematic accuracy. Different types of worm surfaces are briefly outlined. Technological problems concerning the principles of achieving a high degree of precision in machining are also described. Special attention is paid to the shaping of conical helical surfaces. Increasing the manufacturing precision of drive components allows one to achieve both lower backlash values and lower levels of its dispersion. However, this does not ensure that backlash can be eliminated, with its value being kept low during longer periods of operation. This is important in positioning systems and during recurrent operations. Various design solutions for drives in which it is possible to reduce backlash are presented. Results of experiments of a worm gear drive with a worm axially adaptive only locally, in its central section, are presented. In this solution, it is possible to reduce backlash by introducing adjustment settings without disassembling the drive. An important scientific problem concerned defining the principles of achieving a compromise between the effectiveness of reducing backlash and the required load capacity of the drive. In this paper it has been shown that in worm gear drives with a locally axially adaptive worm, as well as with a worm wheel with a deformable rim, it is possible to achieve significant reduction of backlash. In high precision drives—for example, those with an average backlash value of <15 micrometers—this can enable more than a two-fold reduction of the average backlash value and more than a three-fold decrease of the standard deviation of local backlash values.

Performance simulations of engine-gearbox combinations for lightweight passenger cars

2001 ◽  
Vol 215 (2) ◽  
pp. 259-271 ◽  
Author(s):  
P Soltic ◽  
L Guzzella
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Gear Ratio ◽  
Published Data ◽  
Passenger Cars ◽  
Gear Drive ◽  
Different Types ◽  
Variable Transmission ◽  
Low Efficiency ◽  
Gear Drives

This paper compares the fuel consumption of lightweight passenger cars with three different types of engine (one low speed and one high speed naturally aspirated spark ignited, one turbo-charged compression ignited) and two different types of transmission [continuously variable transmission (CVT) and automated gear drive]. All fuel consumption results are obtained using a quasi-static driving cycle simulator. The implemented models are described in detail. The engines are represented through their eficiency maps, which are obtained by scaling published data. Effciency of the transmission (CVT or gear drive) is modelled in dependence on speed, torque and gear ratio. The simulations show that low fuel consumption can be achieved with all those concepts. CVTs show similar results to automated gear drives. The CVT's theoretical advantage of operating the engine at its most fuel-efficient points is compensated by the relatively low efficiency.

The Classification of Early Iron-Smelting Furnaces

1972 ◽  
Vol 52 (1) ◽  
pp. 8-23 ◽  
Author(s):  
H. F. Cleere
Keyword(s):  
Iron Age ◽  
Molten Slag ◽  
Northern Europe ◽  
Early Iron Age ◽  
New Classification ◽  
Air Blast ◽  
Iron Smelting ◽  
Smelting Operation ◽  
Different Types

SummaryThe paper begins by surveying the different types of early iron-smelting furnace, based on a tentative classification proposed by Coghlan in 1956. The ambiguities in this classification are indicated, together with examples of furnaces that do not fall easily into one of its three categories.On the basis of data derived principally from furnaces of the Early Iron Age and Roman periods from northern Europe, the author proposes a new classification into two main groups, differentiated by their provisions or otherwise for the removal of molten slag during the iron-smelting operation. Each of these groups is further subdivided, according to the shape of the furnace superstructure and/or the method of supplying the air blast.

Instantaneous Efficiency and Coefficient of Friction of an Involute Gear Drive

1973 ◽  
Vol 95 (4) ◽  
pp. 1131-1138 ◽  
Author(s):  
E. I. Radzimovsky ◽  
A. Mirarefi ◽  
W. E. Broom
Keyword(s):  
Coefficient Of Friction ◽  
Testing Machine ◽  
Effective Coefficient ◽  
Contact Ratio ◽  
Variable Parameters ◽  
Operational Conditions ◽  
Gear Drive ◽  
Sliding Motion ◽  
Involute Gear ◽  
Gear Drives

In this work the authors, using a testing machine designed for this investigation, determined experimentally the variation in the friction losses in gearing during an individual tooth engagement period. Based upon the obtained data “instantaneous efficiency” of various gear drives and the variation of “apparent coefficient of friction” during the engagement period were evaluated. This “apparent” or “effective” coefficient of friction is a coefficient which represents the effect of the friction due to rolling or a combination of rolling and sliding motion between the engaged teeth in the gear drives. The instantaneous coefficients of friction in the gearing during the engagement cycle were obtained for a large number of different operational conditions. The following factors were used as variable parameters: the torque transmitted by the gears, the speed of gear rotation, the diametral pitch, and the contact ratio of the gearing.

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