Design and development of a ball impact apparatus for the direct measurement of lubricant friction under high pressures and shear rates

摘要

The development of a new ball impact apparatus for the measurement of the traction behaviour of solidified lubricants is described. The normal and tangential forces between an oily plate and an obliquely impacting ball were measured directly on two different forms of apparatus by means of piezoelectric transducers. From the measured forces the coefficient of friction during impact could be calculated. For one particular oil, Santotrac 50, a full set of results is given and these are shown to be in good agreement with values reported previously by others using different forms of experimental equipment.