Friction in low speed lubricated rolling and sliding contacts

Dissertation

Kenneth Holmberg

Research output: ThesisDissertationMonograph

Abstract

A four-disc machine was built for friction measurements at low speed lubricated rolling and sliding contacts.The most important parameters influencing friction in these conditions turned out to be the sliding speed, the lubricant and its additive content, the disc material combination, the lubricant viscosity and the topography of the surfaces.The load, rolling speed and surface roughness had only a slight influence on friction.Values for the coefficient of friction in the range of 0.03 - 0.11 were measured.The mechanisms of lubrication in low speed rolling and sliding conditions is governed by a combination of three effects: the chemical formation of the boundary lubrication film, the creation of a hydrostatic pressure in lubricant trapped by the surface topography and the squeeze effect of lubricant in grooves formed by the surface topography.In conditions of pure rolling at low speeds the lubricant and its additive content has a considerable influence on friction because of a deforming or mangling effect of the boundary lubricant film in the inlet region of the contact.The rolling speed had a significant influence on rolling friction and a slight influence of the disc material combination could be measured.No appreciable influence of load, lubricant viscosity or surface roughness on the coefficient of rolling friction was found.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Helsinki University of Technology
Place of PublicationEspoo
Publisher
Print ISBNs951-38-2014-9
Publication statusPublished - 1984
MoE publication typeG4 Doctoral dissertation (monograph)

Fingerprint

Lubricants
Friction
Surface topography
Lubrication
Surface roughness
Viscosity
Hydrostatic pressure
Topography

Keywords

  • lubrication
  • boundary lubrication
  • friction
  • tribology
  • rolling contacts

Cite this

Holmberg, K. (1984). Friction in low speed lubricated rolling and sliding contacts: Dissertation. Espoo: VTT Technical Research Centre of Finland.
Holmberg, Kenneth. / Friction in low speed lubricated rolling and sliding contacts : Dissertation. Espoo : VTT Technical Research Centre of Finland, 1984. 89 p.
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abstract = "A four-disc machine was built for friction measurements at low speed lubricated rolling and sliding contacts.The most important parameters influencing friction in these conditions turned out to be the sliding speed, the lubricant and its additive content, the disc material combination, the lubricant viscosity and the topography of the surfaces.The load, rolling speed and surface roughness had only a slight influence on friction.Values for the coefficient of friction in the range of 0.03 - 0.11 were measured.The mechanisms of lubrication in low speed rolling and sliding conditions is governed by a combination of three effects: the chemical formation of the boundary lubrication film, the creation of a hydrostatic pressure in lubricant trapped by the surface topography and the squeeze effect of lubricant in grooves formed by the surface topography.In conditions of pure rolling at low speeds the lubricant and its additive content has a considerable influence on friction because of a deforming or mangling effect of the boundary lubricant film in the inlet region of the contact.The rolling speed had a significant influence on rolling friction and a slight influence of the disc material combination could be measured.No appreciable influence of load, lubricant viscosity or surface roughness on the coefficient of rolling friction was found.",
keywords = "lubrication, boundary lubrication, friction, tribology, rolling contacts",
author = "Kenneth Holmberg",
year = "1984",
language = "English",
isbn = "951-38-2014-9",
series = "Publications / Technical Research Centre of Finland",
publisher = "VTT Technical Research Centre of Finland",
number = "16",
address = "Finland",
school = "Helsinki University of Technology",

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Holmberg, K 1984, 'Friction in low speed lubricated rolling and sliding contacts: Dissertation', Doctor Degree, Helsinki University of Technology, Espoo.

Friction in low speed lubricated rolling and sliding contacts : Dissertation. / Holmberg, Kenneth.

Espoo : VTT Technical Research Centre of Finland, 1984. 89 p.

Research output: ThesisDissertationMonograph

TY - THES

T1 - Friction in low speed lubricated rolling and sliding contacts

T2 - Dissertation

AU - Holmberg, Kenneth

PY - 1984

Y1 - 1984

N2 - A four-disc machine was built for friction measurements at low speed lubricated rolling and sliding contacts.The most important parameters influencing friction in these conditions turned out to be the sliding speed, the lubricant and its additive content, the disc material combination, the lubricant viscosity and the topography of the surfaces.The load, rolling speed and surface roughness had only a slight influence on friction.Values for the coefficient of friction in the range of 0.03 - 0.11 were measured.The mechanisms of lubrication in low speed rolling and sliding conditions is governed by a combination of three effects: the chemical formation of the boundary lubrication film, the creation of a hydrostatic pressure in lubricant trapped by the surface topography and the squeeze effect of lubricant in grooves formed by the surface topography.In conditions of pure rolling at low speeds the lubricant and its additive content has a considerable influence on friction because of a deforming or mangling effect of the boundary lubricant film in the inlet region of the contact.The rolling speed had a significant influence on rolling friction and a slight influence of the disc material combination could be measured.No appreciable influence of load, lubricant viscosity or surface roughness on the coefficient of rolling friction was found.

AB - A four-disc machine was built for friction measurements at low speed lubricated rolling and sliding contacts.The most important parameters influencing friction in these conditions turned out to be the sliding speed, the lubricant and its additive content, the disc material combination, the lubricant viscosity and the topography of the surfaces.The load, rolling speed and surface roughness had only a slight influence on friction.Values for the coefficient of friction in the range of 0.03 - 0.11 were measured.The mechanisms of lubrication in low speed rolling and sliding conditions is governed by a combination of three effects: the chemical formation of the boundary lubrication film, the creation of a hydrostatic pressure in lubricant trapped by the surface topography and the squeeze effect of lubricant in grooves formed by the surface topography.In conditions of pure rolling at low speeds the lubricant and its additive content has a considerable influence on friction because of a deforming or mangling effect of the boundary lubricant film in the inlet region of the contact.The rolling speed had a significant influence on rolling friction and a slight influence of the disc material combination could be measured.No appreciable influence of load, lubricant viscosity or surface roughness on the coefficient of rolling friction was found.

KW - lubrication

KW - boundary lubrication

KW - friction

KW - tribology

KW - rolling contacts

M3 - Dissertation

SN - 951-38-2014-9

T3 - Publications / Technical Research Centre of Finland

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Holmberg K. Friction in low speed lubricated rolling and sliding contacts: Dissertation. Espoo: VTT Technical Research Centre of Finland, 1984. 89 p.