| 摘要 |
Disclosed is a yaw driving device for a wind turbine, wherein when the pressure of a gas within a case is increased, the pressure of the gas within the case is automatically reduced without a manual operation, so that the breakage of a seal element is prevented, the leakage of a lubricant oil within the case and the entry of a foreign substance into the case are suppressed, and the increase of the size of a mechanism is suppressed. A relief valve (13) which is projected upwardly is provided on the upper end of a case (12) to which an electric motor (100) is attached. The relief valve (13) is comprised of a communication path (34) and a valve body (32) which opens an opening (34b) facing toward the outside of the communication path (34) in accordance with the increase of the pressure of the gas within the case (12) and closes the same in accordance with the decrease of the pressure. A shoulder portion (23) which is disposed above an oil level (25) of the lubricant oil and which is inwardly stepped, and a wall portion (22) which extends in upward and downward directions are formed on the upper end of the case (12). The opening (34a) of the communication path (34), which faces toward the inside of the case (12), is open at the inside of the shoulder portion (23) and at the outside of the wall portion (22) in the case (12). |
