A New Gears Profile Having Zero Relative Curvature at Many Contact Points (LogiX Tooth Profile)

1990 ◽  
Vol 112 (3) ◽  
pp. 430-436 ◽  
Author(s):  
T. Komori ◽  
Y. Ariga ◽  
S. Nagata
Keyword(s):  
Point Contact ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
New Era ◽  
Contact Points ◽  
History Of ◽  
Surface Durability ◽  
New Type ◽  
Zero Values

We have successfully developed a tooth profile which enables a spur gear having zero relative curvature at contact points under the engagement through the concave/convex pattern of contact and further enables a single flank of the tooth profile to have the infinite number of points where the relative curvature and specific sliding are zero values. We have given a name of “LogiX” to this tooth profile. A W-N (Wildhaber-Novikov) tooth profi¨le has been known as that having the concave/convex pattern of contact. The tooth profile, however, is applied only to a helical gear due to its feature of a point contact. While, on the LogiX tooth profile, an improvement has been made so that a pair of spur gears having the tooth profile may contact each other through the concave/convex pattern of a line-contact which cannot be achieved by the W-N tooth profile. Therefore, the LogiX tooth profile has realized a spur gear whose surface durability is as high as that of the W-N tooth profile. Since the results of durability tests show slightly higher than an involute one, it is expected that a new type heavy duty gear of this tooth profile puts into practical use. Furthermore, the tooth profile will have the possibility of creating the new era in the history of tooth profile theory.

Explicit Parametric Method for Optimal Spur Gear Tooth Profile Definition

2013 ◽  
Vol 633 ◽  
pp. 87-102 ◽  
Author(s):  
Ivana Atanasovska ◽  
Radivoje Mitrovic ◽  
Dejan Momcilovic
Keyword(s):  
Gear Tooth ◽  
Load Capacity ◽  
Parametric Method ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
Element Analysis ◽  
Engineering Research ◽  
Profile Optimization ◽  
Current Engineering

The gear tooth profile has an immense effect on the main operating parameters of gear pairs (load capacity, working life, efficiency, vibrations, etc). In current engineering research and practice, there is a strong need to develop methods for tooth profile optimization. In this paper a new method for selecting the optimal tooth profile parameters of spur gears is described. This method has been named the Explicit Parametric Method (EPM). The addendum modification coefficient, radius of root curvature, and pressure angle of the basic rack for cylindrical gears, have been identified as the main tooth profile parameters of spur gears. Therefore, the EPM selects the optimal values for these three tooth profile parameters. Special attention has been paid to develop a method of adjustment for the particular working conditions and explicit optimization requirements. The EPM for optimal tooth profile parameters of gears uses contact nonlinear Finite Element Analysis (FEA) for calculation of deformations and stresses of gear pairs, in addition to explicit comparative diagrams for optimal tooth profile parameter selection.

Further Evaluation of Spur Gear Tooth Profile Designs Used in Heavily Loaded Transmissions

2011 ◽  
Author(s):  
Nihat Yıldırım ◽  
Hakan I˙s¸c¸i ◽  
Abdullah Akpolat
Keyword(s):  
Gear Tooth ◽  
Transmission Error ◽  
Spur Gear ◽  
Tooth Profile ◽  
Design Parameters ◽  
Preference Order ◽  
Spur Gears ◽  
Tooth Root ◽  
Contact Ratio ◽  
Practical Applications

Aerospace applications require special procedures for component design and manufacturing. Spur gears of different designs, because of their simpler geometries, are used in vital units-transmissions of helicopters and alike aerospace vehicles. In this study, performances of various profile designs of previously researched low and high contact ratio spur gears with some realistic design parameters are studied. Effects of the realistic parameters of variable tooth pair stiffness, relief shape, and adjacent pitch error on Transmission Error (TE), tooth loads and root stresses are presented; composition of these parameters determines the efficiency of the gearbox assembly. Detail of minimization of tooth root stress through optimized/proper design of relief is described. More comprehensive comparison of the gear tooth profile design cases is done to be able to guide aerospace transmission designers for practical applications with realistic parameters for each of the design cases. A preference order is done among the design cases, depending on effect of some design parameters on the results such as tooth loads, tooth root stresses, TE curves and peak-to-peak TE values.

A New Photoelastic Investigation of the Dynamic Bending Stress of Spur Gears

2003 ◽  
Vol 125 (2) ◽  
pp. 365-372 ◽  
Author(s):  
Ming-Jong Wang
Keyword(s):  
Critical Points ◽  
Gear Tooth ◽  
Spur Gear ◽  
Behavioral Characteristics ◽  
Spur Gears ◽  
Bending Stress ◽  
Dynamic Effects ◽  
Contact Points ◽  
Photoelastic Investigation ◽  
Bending Stresses

In this paper, the maximum tensile bending stress (MTBS) and the critical point in the root fillet of spur gear tooth during transmission are determined by a digital photoelastic system involving real time imaging. The behavioral characteristics of the bending stresses of the gear tooth are analyzed at different rotation speeds, transmitted torques, and contact points. Then, the dynamic effects, the various critical points and the maximum tensile bending stresses are compared experimentally and theoretically, and discussed. Finally, the best approaches for determining the maximum bending stress and its position in the root fillet of spur gear tooth are recommended.

scholarly journals A Mathematical Model for Parametric Tooth Profile of Spur Gears

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Guodong Zhai ◽  
Zhihao Liang ◽  
Zihao Fu
Keyword(s):  
Mathematical Model ◽  
Spur Gear ◽  
Parametric Modeling ◽  
Tooth Profile ◽  
Modeling Method ◽  
Spur Gears ◽  
Profile Curve ◽  
Traditional Design ◽  
Mathematical Equations ◽  
Involute Curve

Spur gears are widely used transmission components. In the traditional design process, the noninvolute part of the tooth profile curve is difficult to describe with mathematical equations. This article puts forward a new parametric modeling method, which can describe the modified involute part of spur gears and parameterize and optimize the transition part of the involute curve of the spur gear. And this model of the spur gear can be created by parameters which is input in Scilab software and the spur gear graphic can be completed correspondingly. The experiments show that this modeling method can more quickly produce the standard spur or modified spur gear, and it also improves the efficiency and accuracy of spur gear modeling.

A New Continuous Contact Low-Noise Gear Pump

1983 ◽  
Vol 105 (4) ◽  
pp. 736-741 ◽  
Author(s):  
K. Mitome ◽  
K. Seki
Keyword(s):  
Point Contact ◽  
Practical Method ◽  
Spur Gear ◽  
Helical Gear ◽  
Low Noise ◽  
Tooth Profile ◽  
Gear Pump ◽  
Excellent Performance ◽  
Continuous Contact ◽  
Gear Pumps

Developed is a new low-noise gear pump which has no trapping and whose gears are in continuous one-point contact in the plane of rotation. First this paper studies a practical method to design the tooth profile of a spur gear for a given path of contact. A new tooth profile is obtained by giving a closed path of contact like a figure 8. Basic dimensions are determined and limites of them are obtained. Both theoretical and approximate displacements are expressed in terms of the basic dimensions. Secondly, a helical gear pump is studied. The helical gear can be discussed in the same way as the spur gear by new basic dimensions. Finally some test gear pumps are made and tested. Test prove that this gear pump has excellent performance and durability.

Reduction of Vibration in Spur Gears by an Asymmetric Tooth Profile With High Contact Ratio

2017 ◽  
Author(s):  
Ryo Fujikawa ◽  
Kiyotaka Ikejo ◽  
Soichi Ibaraki ◽  
Kazuteru Nagamura
Keyword(s):  
Thrust Force ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
Gear Pair ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Gear Drive ◽  
Gear Drives ◽  
Helical Gear Pair

Gear drive is a mechanism transmitting a power and a motion through the teeth contact. The number of teeth in contact changes during a mesh cycle. That raises a discontinuity of the mesh stiffness, and causes a gear vibration. The discontinuity implies a direct relationship with the contact ratio of the gear pair. In general, the high contact ratio more than two decreases the discontinuity of the mesh stiffness. Therefore, the increase of the contact ratio is able to reduce the vibration and the noise in the gear drives. An adoption of a helical gear pair is a method to obtain two or more contact ratio. However, that provides a thrust force and a difficulty to machine and assemble. For a spur gear pair, though it is possible to increase the contact ratio by stretching the tooth depth, the tooth thickness may reduce or be excessively sharp at the tooth tip on the addendum circle. In this study, we designed and made a high contact ratio spur gear pair with an asymmetric tooth profile. The gear pair has a large tooth depth to increase the contact ratio, and the asymmetric tooth profile to prevent the sharpness of tooth at the tip circle. In the running test, the vibration and the noise were measured. Consequently, we succeeded in a reduction of vibration and noise in spur gear drives with the asymmetric tooth profile.

Transmission Errors and Noise of Spur Gears Having Uneven Tooth Profile Errors

1979 ◽  
Vol 101 (2) ◽  
pp. 268-273 ◽  
Author(s):  
I. Yuruzume ◽  
H. Mizutani ◽  
T. Tsubuku
Keyword(s):  
Testing Machine ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
Profile Error ◽  
Gear Noise ◽  
Transmission Errors ◽  
Profile Errors ◽  
Tooth Profile Errors ◽  
Gear Rolling

The problems of involute spur gear noise and transmission errors are studied by meshing m3, 40z spur gears. Five kinds of tooth profile errors, such as convex, concave and wave-like, were formed on the test gear teeth by grinding. The value of each tooth profile error is divided into 3 grades, according to the Gear standards of JIS. Transmission errors of 15 test gears and a master gear were measured by a single flank gear rolling tester with a planetary gear system. Gear noise and strains near tooth fillets were measured by running these test gears on a gear noise testing machine with a power absorbing system, in an anechoic room. This paper presents experimental results and studies of the influence of tooth profile error forms on single flank rolling errors, situation of tooth contacts and gear noise while running.

The Influence of the Center-to-Center Distance on the Accuracy of the Serration with the New Gear Hob

2012 ◽  
Vol 217-219 ◽  
pp. 1908-1911
Author(s):  
Ling Li Jin ◽  
Feng He Ma ◽  
Fu Hua Peng
Keyword(s):  
Mathematical Model ◽  
Spur Gear ◽  
Tooth Profile ◽  
Gear Cutter ◽  
New Type ◽  
Set Up ◽  
Profile Errors ◽  
Tooth Profile Errors ◽  
Profile Accuracy ◽  
Center Distance

A gear meshing mathematical model was set up according to the tooth profile normal line method. The influence of the gear cutter-workpiece center distance on the tooth profile accuracy was discussed in spur gear cutting using a new type of gear cutter, with the center distance errors being ±0.005, ±0.01, ±0.02 and ±0.04 respectively. The results show that the machined tooth profile errors at the root circle is less than 1μm, while errors at other parts of the tooth profile are even smaller.

KAZAKH MUSIC CULTURE ON THE GLOBALIZATION CROSSROADS: ETHNIC TRADITIONS VERSUS COMPOSER SCHOOL IN INTERCULTURAL INTERACTION

2020 ◽  
Vol 384 (2) ◽  
pp. 185-193
Author(s):  
A. Raimkulova
Keyword(s):  
20Th Century ◽  
Cultural Policy ◽  
Information Technologies ◽  
Cultural Landscapes ◽  
Social Institutions ◽  
Music Culture ◽  
Oral Transmission ◽  
Intercultural Interaction ◽  
History Of ◽  
New Type

At the present stage, Kazakh musical culture is heterogeneous. It represents traditions coexisting at the same time and interacting with each other: Kazakh ethnic and newly established composer school (tradition). Examining changes in cultural landscapes of the 20th century I reveal the peculiarities of interaction and dialogue between two kinds of culture: ethnic and global (endogenous and exogenous). The procedures include the complex study of the history of Kazakh culture in the 20th century, stylistic analysis of traditional and composer’s music, semiotic approach to intercultural interaction, as far as a comparative analysis of oral and written music of 19th and 20th centuries. On one hand, dramatic changes in the structure of music culture were caused by external objective reasons: new industrial and postindustrial civilization phases (urbanization and information technologies); intensification of interaction with western (mainly Russian) cultures, etc. On the other hand, some changes were inspired by inner factors: diverse development of local song and kui (dombyra piece) traditions; Soviet cultural policy. As a result new type (or layer) of national culture – Kazakh composers’ music – appeared. It was connected with the formation of a national style based on transcriptions and borrowing. Traditional music was influenced by new social institutions (philharmonic halls, theatres, radio, conservatoire) that caused changes in the creative process (decrease of oral transmission, lack of traditional social context) as well as in the style (virtuoso performance, new genres of songs).

Conclusion

2017 ◽  
Author(s):  
Simon A. Waldman ◽  
Emre Caliskan
Keyword(s):  
Turkish Republic ◽  
Fragile State ◽  
New Era ◽  
The Public ◽  
Illiberal Democracy ◽  
History Of ◽  
Election Victory

After another election victory, but this time winning almost 52 per cent of the vote, Recep Tayyip Erdogan became the first popularly elected president in the history of the Turkish Republic. In his victory speech, Erdogan vowed to lead Turkey into a "new era of social reconciliation by leaving old disputes in the Old Turkey." He also called on the public to "mobilize our energy for New Turkey”. However, his polarizing rhetoric and steps towards an illiberal democracy may alienate many Turkish discontents, and unless wounds are healed Turkey risks being a weak and fragile state.

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