Publication detail

Experimental study of lubricant film thickness behavior in the vicinity of real asperities passing through lubricated contact

HARTL, M., FUIS, V., LIŠKA, M.

Original Title

Experimental study of lubricant film thickness behavior in the vicinity of real asperities passing through lubricated contact

English Title

Experimental study of lubricant film thickness behavior in the vicinity of real asperities passing through lubricated contact

Type

journal article - other

Language

en

Original Abstract

This paper presents an experimental study of the influence of real surface micro-geometry on the film thickness in a circular elastohydrodynamic (EHD) contact formed between a real, random, rough surface of steel ball and smooth glass disc. The Phase Shifting Interferometry has been used to measure in situ initial undeformed rough surface profiles whereas Thin Film Colorimetric Interferometry has provided accurate information about micro EHD film thickness behavior over a wide range of rolling speed. Two real roughness features were studied in detail 56 nm high ridge and 90 nm deep groove, both transversely oriented to the direction of surface motion. It has been shown that ridge is heavily deformed in a loaded contact and its height increases with increasing rolling speed. The asperity tip film thickness behavior is quite similar to the contact average film thickness when the film thickness is higher than the undeformed ridge height. However below this limit the film is thicker than what the EHD theory predicts. For the groove, a local reduction in film thickness at the leading edge has been observed. When the groove is passing through the EHD conjunction, it maintains its undeformed shape. The behavior of both roughness features studied shows good agreement with previous experimental observations conducted using artificially-produced ridge and groove.

English abstract

This paper presents an experimental study of the influence of real surface micro-geometry on the film thickness in a circular elastohydrodynamic (EHD) contact formed between a real, random, rough surface of steel ball and smooth glass disc. The Phase Shifting Interferometry has been used to measure in situ initial undeformed rough surface profiles whereas Thin Film Colorimetric Interferometry has provided accurate information about micro EHD film thickness behavior over a wide range of rolling speed. Two real roughness features were studied in detail 56 nm high ridge and 90 nm deep groove, both transversely oriented to the direction of surface motion. It has been shown that ridge is heavily deformed in a loaded contact and its height increases with increasing rolling speed. The asperity tip film thickness behavior is quite similar to the contact average film thickness when the film thickness is higher than the undeformed ridge height. However below this limit the film is thicker than what the EHD theory predicts. For the groove, a local reduction in film thickness at the leading edge has been observed. When the groove is passing through the EHD conjunction, it maintains its undeformed shape. The behavior of both roughness features studied shows good agreement with previous experimental observations conducted using artificially-produced ridge and groove.

Keywords

film thickness; elastohydrodynamic

RIV year

2004

Released

01.09.2004

ISBN

0569-8197

Periodical

Tribology Transactions

Year of study

47

Number

3

State

US

Pages from

376

Pages to

385

Pages count

10

Documents

BibTex


@article{BUT42401,
  author="Martin {Hartl} and Ivan {Křupka} and Vladimír {Fuis} and Miroslav {Liška}",
  title="Experimental study of lubricant film thickness behavior in the vicinity of real asperities passing through lubricated contact",
  annote="This paper presents an experimental study of the influence of real surface micro-geometry on the film thickness in a circular elastohydrodynamic (EHD) contact formed between a real, random, rough surface of steel ball and smooth glass disc. The Phase Shifting Interferometry has been used to measure in situ initial undeformed rough surface profiles whereas Thin Film Colorimetric Interferometry has provided accurate information about micro EHD film thickness behavior over a wide range of rolling speed. Two real roughness features were studied in detail  56 nm high ridge and 90 nm deep groove, both transversely oriented to the direction of surface motion. It has been shown that ridge is heavily deformed in a loaded contact and its height increases with increasing rolling speed. The asperity tip film thickness behavior is quite similar to the contact average film thickness when the film thickness is higher than the undeformed ridge height. However below this limit the film is thicker than what the EHD theory predicts. For the groove, a local reduction in film thickness at the leading edge has been observed. When the groove is passing through the EHD conjunction, it maintains its undeformed shape. The behavior of both roughness features studied shows good agreement with previous experimental observations conducted using artificially-produced ridge and groove.",
  chapter="42401",
  journal="Tribology Transactions",
  number="3",
  volume="47",
  year="2004",
  month="september",
  pages="376",
  type="journal article - other"
}