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 language | English |
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Qualification | Doctor Degree |
Awarding Institution |
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Place of Publication | Espoo |
Publisher | |
Print ISBNs | 951-38-2014-9 |
Publication status | Published - 1984 |
MoE publication type | G4 Doctoral dissertation (monograph) |
Keywords
- lubrication
- boundary lubrication
- friction
- tribology
- rolling contacts