In this study, the infrared temperature mapping technique, originally developed by Sanborn and Winer (Trans ASME J Tribol
93:262–271, 1971) and extended by Spikes et al. (Tribol Lett 17(3):593–605, 2004), has been made more sensitive and used to
study the temperature rise of elastohydrodynamic contacts in pure rolling. Under such conditions lubricant shear heating within
the contact is considered negligible and this allows temperature changes due to lubricant compression to be investigated.
Pure rolling surface temperature distributions have been obtained for contacts lubricated with a range of lubricants, included
a group I, and group II mineral oil, a polyalphaolefin (group IV), the traction fluid Santotrac 50 and 5P4E, a five-ring polyphenyl-ether.
Resulting maps show the temperature rise in the contact increases in the inlet due to compression heating and then decreases
and in most cases becomes negative in the exit region due to the effect of decompression. Temperature changes increase with
entrainment speed but in the current tests are always very small, and less than 1 °C. Contact temperature rises from compression
were compared to those from sliding contacts (where a slide-roll ratio of 0.5 was applied). Here the contribution to the contact
temperature from compression is shown to decrease dramatically with entrainment speed. The lubricant 5P4E is found to behave
differently from other lubricants tested in that it showed a peak in temperature at the outlet. This effect becomes more pronounced
with increasing speed, and has tentatively been attributed to a phase change in the exit region. Using moving heat source
theory, the measured temperature distributions have been converted to maps showing rate of heat input into each surface and
the latter compared with theory. Qualitative agreement between theory and experiment is found, and a more accurate theoretical
comparison is the subject of ongoing study.
Keywords EHD - Compression - Infrared emission - Temperature - Lubricants - Elastohydrodynamic (EHL) - Thermal effects in EHL - Friction mechanisms - Rolling friction