Patent ID: 8215912

Claim:
A wind turbine generator, comprising: a tower standing on a foundation, a nacelle installed at an upper end of the tower, an electric generator installed in the nacelle, a wind turbine blade, a rotor head coupled to the wind turbine blade via a blade rotating ring bearing, and rotatably supported by the nacelle to be rotated by wind power to drive the electric generator to generate electricity, a pitch control mechanism configured to adjust a pitch angle of the wind turbine blade via the blade rotating ring bearing provided between the wind turbine blade and the rotor head, a grease supply and discharge assembly disposed in the rotor head, the grease supply and discharge assembly including a grease supply device having a supplied grease tank and a pump for supplying lubricant oil from the supplied grease tank to the blade rotating ring bearing, and a grease discharge device for forcibly sucking and recovering discharged grease from the blade rotating ring bearing, wherein the grease discharge device includes a vacuum pump for sucking and recovering the discharged grease from the blade rotating ring bearing, a reservoir tank for storing the recovered discharged grease with a gas portion, and a discharged grease channel connecting the blade rotating ring bearing via the vacuum pump to the reservoir tank, the reservoir tank is placed near a rotation axis of the rotor head, and the vacuum pump is located in the gas portion of the reservoir tank.