Tribocharging in a rotating shaft-oil-seal system and the effect of an external electric field

The results are shown of tests on the effect of an auxiliary external DC electric field on the braking torque of a rotating shaft. Experiments were carried out on a simplified model of an engine in whose interior a metal shaft rotated with given angular velocities. The shaft was lubricated with different oils producing an oil film between the shaft's surface and a lip seal. The influence of different oil temperatures on the braking torque was also examined. The results are presented here for fresh Polish oil LOTOS 15W40 and a lip seal diameter of 88 mm. An increase in the negative DC voltage applied between the shaft and stiffening ring of the lip seal caused a reduction in braking torque.