| 摘要 |
<p>In order to contribute to cost and environmental preservation by preventing a hydraulic pump from taking in air and being contaminated by oil and by reducing the use amount of the oil, a pitch drive device according to the present invention comprises: hydraulic actuators (15) for changing the pitch angles of wind turbine blades (5); a hydraulic pump (22) for supplying oil to the hydraulic actuator (15); a high-pressure oil line (24) for guiding the oil discharged from the hydraulic pump (22) to the hydraulic actuators (15); a low-pressure oil line (25) for returning the oil discharged from the hydraulic actuator (15) to the hydraulic pump (22); and a pressure control device (26) for retaining a surplus amount of the oil and refilling the low-pressure oil line (25) with the oil so as not to generate negative pressure in an oil intake portion of the hydraulic pump (22). The hydraulic actuator (15), the hydraulic pump (22), the high-pressure oil line (24), the low-pressure oil line (25), and the pressure control device (26) constitute a closed hydraulic pump (32) that does not open to the atmosphere and is filled with the oil.</p> |
