A rotor bearing for a wind turbine with a machine housing rotatably received on a tower. The housing has a generator, a wind-driven rotor with a rotor hub carrying rotor blades and a large rolling bearing carrying the rotor. The large rolling bearing has a first bearing ring, which is non-rotatably fastened on the housing and arranged coaxially to the rotor hub, and a second hearing ring, which is rotatably held on the first bearing ring and fastened to the rotor hub, and rolling elements rolling between the bearing rings. The large rolling bearing is connected to a planetary gear which is connected to the generator and has a ring gear with a peripheral internal gear, planet gears received on planet carriers and a central sun gear. The radially inner bearing ring is also the ring gear connected to the generator, its interior being configured with the peripheral internal gear.