Publication detail

Influence of Free Water Droplets on Film Formation Under Point Contact Grease Lubrication

HAN, Y. ŠPERKA, P. WANG, J. KŘUPKA, I. HARTL, M. LI, W. WANG, X. WEI-MIN, L.

English title

Influence of Free Water Droplets on Film Formation Under Point Contact Grease Lubrication

Type

journal article in Web of Science

Language

en

Original abstract

The influence of the grease-water two-phase emulsion on the bearing tracks on the film formation has been studied by carrying out optical interferometry experiments on a ball disk test rig to observe the dynamic film-forming behavior of lubricating grease under steady-state and micro-oscillation conditions. It is found that free water causes a brief rise in the grease film under steady-state conditions, specifically due to the grease-water phase connecting the oil reservoirs on both sides. The experiment determines that the state of the phase before entering the elastohydrodynamic lubrication (EHL) contact is water-in-oil. For the reciprocating motion and oscillation, the effects of the amount of free water and the length of the motion stroke are discussed in detail. It is found that for reciprocating movements with long stroke lengths, the effect of free water is summarized to enhance the fluidity of the fibrous mass of the grease thickener in the first few cycles of the movement. For shorter stroke lengths, the effect of free water is a scouring effect on the contact zone grease after 100 cycles. This paper provides new insights into the effects that cause water pollution to the point of contact lubrication during the transformation from reciprocating motion to fretting.

English abstract

The influence of the grease-water two-phase emulsion on the bearing tracks on the film formation has been studied by carrying out optical interferometry experiments on a ball disk test rig to observe the dynamic film-forming behavior of lubricating grease under steady-state and micro-oscillation conditions. It is found that free water causes a brief rise in the grease film under steady-state conditions, specifically due to the grease-water phase connecting the oil reservoirs on both sides. The experiment determines that the state of the phase before entering the elastohydrodynamic lubrication (EHL) contact is water-in-oil. For the reciprocating motion and oscillation, the effects of the amount of free water and the length of the motion stroke are discussed in detail. It is found that for reciprocating movements with long stroke lengths, the effect of free water is summarized to enhance the fluidity of the fibrous mass of the grease thickener in the first few cycles of the movement. For shorter stroke lengths, the effect of free water is a scouring effect on the contact zone grease after 100 cycles. This paper provides new insights into the effects that cause water pollution to the point of contact lubrication during the transformation from reciprocating motion to fretting.

Keywords in English

bearings;elastohydrodynamic lubrication;films;grease lubrication;lubricants;rolling

Released

01.07.2023

Publisher

ASME

Location

NEW YORK

ISSN

0742-4787

Volume

145

Number

7

Pages from–to

074101-1–074101-17

Pages count

17

BIBTEX


@article{BUT187554,
  author="Yiming {Han} and Matthias {Thiex} and Petr {Šperka} and Jing {Wang} and Ivan {Křupka} and Martin {Hartl} and Weimin {Li} and Xiaobo {Wang} and Liu {Wei-Min},
  title="Influence of Free Water Droplets on Film Formation Under Point Contact Grease Lubrication",
  year="2023",
  volume="145",
  number="7",
  month="July",
  pages="074101-1--074101-17",
  publisher="ASME",
  address="NEW YORK",
  issn="0742-4787"
}