Temat: adhesion forces - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: A study on the adhesion at a micro- and nano-lubrication
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/245327.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: adhesion forces
micro- and nano-lubrication
micro-bearings
Opis:: In this paper describes the study on the adhesion forces at a nano-contact and micro- and at a nano-lubrication. Here are elaborated the dependences between oil dynamic viscosity in super thin boundary layer and adhesion forces as well influences of adhesion forces in micro- and nano-level on the friction forces in micro- and nano-scale arising between two cooperating surfaces in micro-bearings. Up to now the influence of adhesion on oil viscosity changes and on the oil flow in micro-bearing gap was not considered in analytical way. Present paper elaborates the preliminary assumptions of hydrodynamic theory of lubrication for micro-bearing in the case if during the lubrication the adhesion forces are taking into account. In this paper are derived theformulas of pressure distributions, friction forces and friction coefficients where the adhesion forces are considered. The changes of adhesion forces in micro-contact of two bodies dependon the load direction. Load carrying capacity increases implied by the oil dynamic viscosity increases caused by the adhesion and cohesion forces attain about from 20% to 30% in comparison to the viscosity and capacity values in classical form.
Źródło:: Journal of KONES; 2009, 16, 4; 499-506
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Adhesion influence on the oil velocity and friction forces in hyperbolic microbearing gap
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/247611.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: adhesion forces
hyperbolic micro-bearing
oil velocity
hydrodynamic pressure
Opis:: In this paper are presented the influences of the adhesion forces occurring in hyperbolic micro contact on the oil velocity and friction forces in hyperbolic micro bearing gap. Here are elaborated the dependences between adhesive forces and oil dynamic viscosity in super thin boundary layer and influences of adhesive forces on the oil velocities and friction forces in micro- and nano-scale arising between two cooperating hyperbolic surfaces in micro-bearings. Oil dynamic viscosity is a sum of classical viscosity and viscosity caused by adhesion and cohesion forces. In hyperbolic micro-bearing the influence of adhesive forces on friction forces is visible not only in friction forces caused by the hydrodynamic pressure but also in friction forces caused by the oil flow velocity. The pressure distributions and capacity values in machine hyperbolic slide micro-bearings are determined in the lubrication region which is defined on the micro-bearing surfaces. Numerical calculations are performed in Mathcad 14 Professional Program implemented by virtue of difference method. In this paper are derived the formulas for velocity components, pressure distributions, friction forces and friction coefficients in hyperbolic coordinates and at the same time the adhesion forces are considered. Up to now the influence of adhesion forces on oil velocity and friction force changes in hyperbolic micro-bearing gap were not considered in analytical way. Present paper elaborat es the preliminary assumptions of hydrodynamic theory of lubrication for hyperbolic micro-bearing in the case if during the lubrication the adhesion forces are taken into account.
Źródło:: Journal of KONES; 2010, 17, 3; 483-489
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Tribologia rzepu syntetycznego
Tribology of synthetic turnip burr
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/190276.pdf
Data publikacji:: 2010
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:: tribologia rzepu
tarcie adhezyjne
rzepy syntetyczne
siły adhezji
siły kohezji
turnip tribology
adhesion friction
synthetic turnips
adhesion forces
cohesion forces
Opis:: Niniejsza praca przedstawia tribologiczny opis mikrowęzłów tarciowych, o dużej wartość siły tarcia adhezyjnego pomiędzy stykającymi się powierzchniami dwóch elementów. Rzepy syntetyczne są przykładem technicznym węzłów tarcia w mikroskali, których charakterystyka jest zbliżona do charakterystyki rzepu naturalnego w postaci dużej ilości mikrohaczyków występujących w owocostanie łopianu. Rzep syntetyczny składa się z dwóch elementów, z tym że powierzchnia jednego jest pokryta dużą ilością mikrohaczyków, natomiast powierzchnia drugiego ma warstwę z licznymi mikropętelkami. Przy docisku obu takich elementów następuje ich zespolenie. Ponieważ mikrohaczyki i mikropętelki są mikroskopijnych wymiarów, stąd siły zaczepu pomiędzy nimi są porównywalne z siłami tarcia i adhezji. Opisany w pracy mechanizm węzłów tarcia ma zastosowanie przy produkcji rzepów syntetycznych odpornych na zużycie.
Present paper shows the tribological description of friction micro-nods where the largest adhesion friction forces between two cooperating surfaces ought to be produced. The presented development has applications during the production of fasteners with minimum wear. In 1948, the Swiss engineer George de Mestral was cleaning his dog of burrs picked up on a walk when he realised how the hooks of the burrs clung to the fur. George de Mestral named his invention "Velcro", which is a portmanteau of the two French words velours and crochet, or "hook". Velcro is a brand name of fabric hook-and-loop fasteners. It consists of two layers: a "hook" side, which is a piece of fabric covered with tiny hooks, and a "loop" side, which is covered with even smaller and "hairier" loops. When the two sides are pressed together, the hooks catch in the loops and hold the pieces together. When the layers are separated, the strips make a characteristic "ripping" sound. Velcro hook-and-loop fasteners can be made of many things. The first samples were made of cotton, which proved to be impractical. Nylon and polyester are the fibers most commonly used now. Velcro fasteners made of Teflon loops, polyester hooks, and glass backing are used on space shuttles. The term Velcro is a registered trademark in most countries. Generic terminology for these fasteners include "hook and loop", "burr" and "touch" fasteners.
Źródło:: Tribologia; 2010, 6; 219-227
0208-7774
Pojawia się w:: Tribologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: A new problem of hydrodynamic lubrication with temperature and viscosity variations in gap height direction
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/245652.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: liquid viscosity changes in thin gap height direction
temperature
adhesion or capillary forces variations in thin gap height direction new analytical solutions
Opis:: Numerous Authors of scientific papers occurring in hydrodynamic theory of slide bearing lubrication, up to now almost always had neglected the oil dynamic viscosity variations caused by temperature, adhesion forces, capillary forces, or hydrogen ion concentration across the film thickness by virtue of the statement of the constant temperature as well constant adhesion as capillary forces in the thin bearing gap height direction. In addition, simultaneously by virtue of boundary layer simplifications for energy equation and by virtue of new measurements performed in micro and nano- level follows that oil temperature gradients and its values differences and adhesion or capillary gradients of forces in bearing gap height directions are not negligible small. The contemporary hydrodynamic theory of lubrication for non-isothermal lubricant flow is unfortunately based on the assumption of constant viscosity values across the film thickness, despite abovementioned self-evident contradiction between the fact of constant viscosity and simultaneously temperature variations in gap height direction. Such problem was up to now not sufficient critical examined and explained in practical and theoretical sense. After Authors, knowledge by virtue of above problem the most scientific papers in the domain of non-isothermal and lamellar hydrodynamic slide bearing or biobearing lubrication were up to now not sufficient correctly solved. It denotes that the main hydrodynamic lubrication solutions presenting for example hydrodynamic pressure by the modified Reynolds equation and temperature by the energy conservation equation are not sufficiently correctly obtained and next not correctly solved. Therefore are assumed simultaneously the temperature T and oil dynamic viscosity variations in length, width and bearing gap- height directions. From this assumption follows, that the energy equation must be solved simultaneously with the equations of motion i.e. consequently with pressure equation where viscosity depends on temperature and temperature depends on the coordinate in gap height direction.
Źródło:: Journal of KONES; 2016, 23, 2; 423-430
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Adhesion and capilarity in micro-bearing lubrication
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/245795.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: adsorption
adhesion
capillary forces
micro-bearing lubrication
Opis:: Present paper shows the some main phenomena which have important influence on the micro-bearing operating parameters. To above mentioned phenomena belong: adhesion forces, adsorption forces, capillary forces, elastic and hyperelastic deformations of cooperating micro-bearing surfaces, Van-der Waals electrostatic forces on the micro-bearing surfaces. Because the height of super thin micro-bearing gap is very small often smaller than l micrometer, hence the adhesion forces and capillary forces arising in micro-bearing gap, provoke the oil dynamic viscosity changes. This fact leads to the hydrodynamic pressure and bearing carrying capacity changes. The performed research play off the main role of mechanical micro-deformations of cooperating micro-bearing surfaces on non-Newtonian oil dynamic viscosity and here are indicated the influence of capillary force on adhesion forces in micro-scale. The micro-deformations of the micro-bearing gap height are effecting the changes of oil flow velocity in the gap, this fact leads to the share rate changes and therefore we obtain changes of apparent viscosity of the non-Newtonian oil.
Źródło:: Journal of KONES; 2009, 16, 3; 489-495
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "adhesion forces" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język