scholarly journals Cylindrical Gears with Contact Areas Distributed Along the Arc Teeth Length

2021 ◽  
Vol 24 (2) ◽  
pp. 33
Author(s):  
V N Syzrantsev
Keyword(s):  
Contact Areas ◽  
Cylindrical Gears

Проблема повышения надежности приводов высоконагруженных машин связана с обеспечением работоспособности цилиндрических передач при наличии углов перекоса зубьев в зацеплении, вызываемых ошибками изготовления и сборки передач, а также податливостью их элементов и корпусных деталей. Эффективным направлением решения проблемы является переход от цилиндрических передач с прямыми, косыми зубьями на передачи с арочными зубьями. По сравнению с прямыми или косыми зубьями изгибная прочность арочных зубьев на 20…30 % выше. Процессы формообразования поверхностей арочных зубьев позволяют в их зацеплении получать линейный, локально-линейный, точечный характер касания, обеспечивать оптимальный закон распределения нагрузки по площадке контакта. В работе рассмотрены особенности компенсации перекоса зубьев в зацеплении перемещением (самоустановкой) шестерни или колеса с арочными зубьями вдоль оси. Показано, что самоустановка колес происходит только для постоянного крутящего момента и неменяющегося угла перекоса. Для компенсации случайного угла перекоса в условиях изменяющегося крутящего момента предложена адаптивная цилиндрическая передача с арочными зубьями, в зацеплении которых имеются две разнесенные по длине зоны контакта. Колесо передачи состоит из двух полуколес, разделенных упругой прокладкой. Возникающие в зонах контакта осевые силы уравновешивают друг друга и обеспечивают самоустановку полуколес при изменении угла перекоса. Нарезание арочных зубьев на обоих полуколесах осуществляется одновременно, поэтому трудоемкость изготовления адаптивной передачи с арочными зубьями не изменяется. Для полуобкатного варианта формообразования поверхностей арочных зубьев адаптивной цилиндрической передачи представлены результаты расчета положения рабочих линий в зацеплении, размеры тормозных зон касания поверхностей арочных зубьев.

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

Capillary pressure, osmotic pressure and bubble contact areas in foams

Soft Matter ◽  
2021 ◽  
Author(s):  
Reinhard Höhler ◽  
Jordan Seknagi ◽  
Andrew Kraynik
Keyword(s):  
Osmotic Pressure ◽  
Capillary Pressure ◽  
Continuous Phase ◽  
Dispersed Phase ◽  
Average Pressure ◽  
Contact Areas ◽  
The Difference

The capillary pressure of foams and emulsions is the difference between the average pressure in the dispersed phase and the pressure in the continuous phase.

scholarly journals Study of Machining of Gears with Regular and Modified Outline Using CNC Machine Tools

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2913
Author(s):  
Rafał Gołębski ◽  
Piotr Boral
Keyword(s):  
Machine Tools ◽  
Coordinate Measuring Machine ◽  
Optical Microscope ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Cnc Milling ◽  
Cnc Machine ◽  
Cylindrical Gears ◽  
Measuring Machine ◽  
Five Axis

Classic methods of machining cylindrical gears, such as hobbing or circumferential chiseling, require the use of expensive special machine tools and dedicated tools, which makes production unprofitable, especially in small and medium series. Today, special attention is paid to the technology of making gears using universal CNC (computer numerical control) machine tools with standard cheap tools. On the basis of the presented mathematical model, a software was developed to generate a code that controls a machine tool for machining cylindrical gears with straight and modified tooth line using the multipass method. Made of steel 16MnCr5, gear wheels with a straight tooth line and with a longitudinally modified convex-convex tooth line were machined on a five-axis CNC milling machine DMG MORI CMX50U, using solid carbide milling cutters (cylindrical and ball end) for processing. The manufactured gears were inspected on a ZEISS coordinate measuring machine, using the software Gear Pro Involute. The conformity of the outline, the tooth line, and the gear pitch were assessed. The side surfaces of the teeth after machining according to the planned strategy were also assessed; the tests were carried out using the optical microscope Alicona Infinite Focus G5 and the contact profilographometer Taylor Hobson, Talysurf 120. The presented method is able to provide a very good quality of machined gears in relation to competing methods. The great advantage of this method is the use of a tool that is not geometrically related to the shape of the machined gear profile, which allows the production of cylindrical gears with a tooth and profile line other than the standard.

The Research on Tooth Profile Total Deviation Measuring Method Based on Coordination Measuring Machine

2012 ◽  
Vol 184-185 ◽  
pp. 789-792
Author(s):  
Bing Li ◽  
Yu Lan Wei ◽  
Meng Dan Jin ◽  
Ying Ying Fan
Keyword(s):  
Mathematical Model ◽  
Data Processing ◽  
High Precision ◽  
Gear Tooth ◽  
Measuring Method ◽  
Tooth Profile ◽  
Cylindrical Gears ◽  
Total Deviation ◽  
Measuring Machine

Put forward a method that use scatter points which got in different places to measure the involution cylindrical gears, give a mathematical model that use the discrete points to sure the total deviation of gear tooth profile. The experience results show that this way is of high precision in measurement points, measurement an error data processing less intervention, etc.

Fuji film and ultrasound measurement of total knee arthroplasty contact areas

2001 ◽  
Vol 16 (3) ◽  
pp. 367-375 ◽  
Author(s):  
R. Zdero ◽  
P.V. Fenton ◽  
J. Rudan ◽  
J.T. Bryant
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Ultrasound Measurement ◽  
Contact Areas ◽  
Total Knee ◽  
Fuji Film

Cylindrical Gears with Increased Contact Area – Proposal of Application in Watercrafts Power Transmission Systems

2015 ◽  
Vol 236 ◽  
pp. 26-30 ◽  
Author(s):  
Michał Batsch ◽  
Tadeusz Markowski ◽  
Wojciech Homik
Keyword(s):  
Power Transmission ◽  
Point Contact ◽  
Surface Strength ◽  
Hertz Theory ◽  
Cylindrical Gears ◽  
Position Errors ◽  
Power Transmission Systems ◽  
Involute Gears ◽  
Maximum Contact ◽  
Two Bodies

Paper presents the method for obtaining maximum contact pressure of Novikov gears. Described surface strength calculation method is based on Hertz theory of two bodies being in point contact. What’s more the influence of gear position errors on maximum contact stresses has been presented. Also the comparison of Hertz stresses for Novikov and involute gears has been made.

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