A double tapered roller bearing in TDO-configuration transfers the rotor loads from the hub into the machine housing. Bearing and gearbox are arranged in such a way that the dynamic rotor-loads can not have a harmful impact on the tooth engagements. The planetary gear is driven by the hollow wheel and the planetary shafts are fixed in a stationary cage. Hereby the shafts running on friction bearings as well as the gear meshings can be lubricated ideally.