The cover 13 can be connected to the bearing bush 4 by such means as bonding, using an interference fit or by welding.A tapered capillary seal 21, which can be molded into the shaft 2 and/or alternatively into the bearing bush 4, is provided at the end of the shaft that protrudes from the bearing bush 4.An annular rotor component 9 is fixed approximately in the middle of the outside circumference