Pitch driving unit for wind-turbine rotor blade and wind power generator equipped with the same

摘要

A pitch driving unit according to the present invention is equipped with hydraulic actuators that change the pitch angles of wind turbine blades; a hydraulic pump that supplies oil to the hydraulic actuators; a high-pressure oil line that guides the oil discharged from the hydraulic pump to the hydraulic actuators; a low-pressure oil line that returns the oil discharged from the hydraulic actuators to the hydraulic pump; and a pressure control unit that stores a surplus amount of the oil and that refills the low-pressure oil line with the oil so as not to generate negative pressure at an oil intake portion of the hydraulic pump, wherein the hydraulic actuators 15, the hydraulic pump, the high-pressure oil line, the low-pressure oil line, and the pressure control unit constitute a closed hydraulic circuit that does not open to the atmosphere, the closed hydraulic circuit being filled with the oil.