Publication detail
Abnormal lubricant aggregation on roughness features in a rolling–sliding elastohydrodynamic contact
ŠPERKA, P. OMASTA, M. KŘUPKA, I. HARTL, M.
Czech title
Abnormální agregace maziva na povrchových nerovnostech v elastohydrodynamickém kontaktu za prokluzu
English title
Abnormal lubricant aggregation on roughness features in a rolling–sliding elastohydrodynamic contact
Type
journal article in Web of Science
Language
en
Original abstract
Any practical surface has some roughness which tends to decrease film thickness in concentrated contacts and increase the risk of surface failures. Surface roughness is deformed but roughness also influences the lubrication process. Therefore, it is important to understand these constrains, to predict a real performance of rough surfaces. It was already reported that roughness tends to flatten inside the contact under rolling–sliding conditions. However, this paper presents experiments showing an abnormal effect inside point contact when the additional lubricant is aggregated on the roughness feature (ridge). Enhanced roughness deformation has a protecting function against direct asperities contacts. The relationship to lubricant speed changes inside the contact, a role of thermal effect and possibility of phase transitions are discussed.
Czech abstract
Povrchy běžných součástí obsahují nerovnosti, které snižují tloušťku filmu v koncentrovaných bodových kontaktech a tím zvýšit riziko poškození povrchu. Nerovnosti se uvnitř kontaktu deformují, zároveň také ovlivňují mazací proces. Proto je důležité porozumět těmto vazbám, aby bylo možné přesněji predikovat skutečné chování povrchů s nerovnostmi. Je známo, že nerovnosti jsou deformovány prakticky do roviny uvnitř kontaktu za prokluzu. V tomto příspěvku jsou prezentovány experimenty, které ukazují abnormální chování nerovností uvnitř kontaktu, mazivo se agreguje na prvcích povrchu. Toto chování přispívá k oddělení třecích povrchů a brání přímému styku mezi vrcholky nerovností na površích. Diskutovány jsou vazby na změny rychlosti toku maziva uvnitř kontaktu, teplotní jevy a fázové změny maziva.
English abstract
Any practical surface has some roughness which tends to decrease film thickness in concentrated contacts and increase the risk of surface failures. Surface roughness is deformed but roughness also influences the lubrication process. Therefore, it is important to understand these constrains, to predict a real performance of rough surfaces. It was already reported that roughness tends to flatten inside the contact under rolling–sliding conditions. However, this paper presents experiments showing an abnormal effect inside point contact when the additional lubricant is aggregated on the roughness feature (ridge). Enhanced roughness deformation has a protecting function against direct asperities contacts. The relationship to lubricant speed changes inside the contact, a role of thermal effect and possibility of phase transitions are discussed.
Keywords in Czech
elastohydrodynamické mazání, drsnost povrchu, efekty povrchových nerovností, teorie amplitudového útlumu, tloušťka filmu, kolísání tlaku, reologie maziva, podmínky v kontaktu
Keywords in English
Elastohydrodynamic lubrication, surface roughness, roughness effects, amplitude attenuation theory, film thickness, pressure variations, lubricant rheology, in-contact conditions
Released
29.02.2016
Publisher
Elsevier
Location
Anglie
ISSN
0301-679X
Volume
94
Number
1
Pages from–to
346–351
Pages count
6
BIBTEX
@article{BUT134834,
author="Petr {Šperka} and Milan {Omasta} and Ivan {Křupka} and Martin {Hartl},
title="Abnormal lubricant aggregation on roughness features in a rolling–sliding elastohydrodynamic contact",
year="2016",
volume="94",
number="1",
month="February",
pages="346--351",
publisher="Elsevier",
address="Anglie",
issn="0301-679X"
}