A wind power installation comprising one or more rotor blades, a rotor hub to which the rotor blade or blades are mounted, and a generator for generating electrical power, wherein the generator has a generator stator and a generator rotor which is non-rotatably connected to the rotor hub and which is rotatable about an axis, wherein the rotor hub and the generator rotor have a common main bearing system or means which is subdivided into two bearing portions which are spaced from each other in the direction of the axis, wherein in that the first bearing portion has a first radial plain bearing and a first axial plain bearing and the second bearing portion has a second radial plain bearing and a second axial plain bearing.