Performances of automotive lubricants – tests on four ball machine

Abstract

In this paper an automotive full synthetically lubricant is tested on a four ball machine. A new data acquisition system is developed, based on tensometric strain gauges principle. In order to interpret the data statistically (signal to noise ratio, skewness and kurtosis etc.) and to directly display the values of the instantaneous friction coefficient, a LabVIEW interface is created. The effect of the sustaining rolling bearing on the mean friction torque and instantaneous friction coefficient between the rotating upper ball and the three stationary balls of the four ball machine’s testing device is also evaluated. For the synthetically motor oil the last non-seizure load (LNSL), initial seizure load (ISL), and the weld points (WP) were established. The new data acquisition system and interface allow the exact prediction of lubricant film seizure. The experimental values of the friction coefficient correspond as order of magnitude with those from literature.