The effect of temperature on traction in elastohydrodynamic lubrication

Abstract

An experimental study has been made of the effect of temperature on traction in elastohydrodynamic conditions with a range of nine fluids. The pressure coefficient of viscosity falls with increase of temperature and this, combined with the fall in the viscosity at atmospheric pressure, leads to very great changes in the effective viscosity within the elastohydrodynamic contact. Thus whereas at low rates of shear and low temperature the fluid in the high pressure zone may behave as an elastic solid, when the temperature is raised it reverts to its liquid form with a viscosity of the order of 10 ² Pa s or less. At high rates of shear, the fluid behaves as a non-Newtonian liquid of the Eyring type at all temperatures within the range of the experiments, i.e. from 30 to 110 °C.