In an electrical machine having a roller bearing, whose inner ring is seated on the rotor shaft of the electrical machine, whose outer ring is seated in a housing and which is located in a closed area, the roller bearing is intended to be protected against electrical breakdowns. For this purpose, the area contains a liquid on an aqueous basis, whose level overhangs the external contour of the inner ring at its lowest point. The inner ring and the outer ring are therefore conductively connected and the voltage can be equalized between the rotor and the housing of the electrical machine, without any impediment and without breakdowns. In an application as a geared motor, the lubricant for the gearbox is also a liquid on an aqueous basis.