Study on the deposition of carbon black particles onto the rubbing surface of sliding bearings

With respect to a phenomenon of particles deposition onto a rubbing surface of sliding bearing, in this paper we report the deposition of carbon black particles in turbine oil onto a bearing surface by fundamental bearing test, and also report a first measurement of streaming electrification generated at the interface between lubricating oil and the bearing surface. The main results are as follows. (1) The deposition of carbon black particles were occurred both on the stationary piece and on the rotational piece of the sliding bearing. (2) The bearing surfaces were positively electrified and its quantity of electricity tended to increase with increasing a sliding velocity and with decreasing a bearing clearance. As a conclusion, it is inferred that a mechanism of carbon black particles deposition onto bearing surfaces is closely related to the electrostatic attraction between particles electrified negatively and bearing surfaces electrified positively.