| The main objective of this invention is to increase the efficiency of a degassing process unit and reduce the overall device size in a rotating electric machine with a shaft seal device. To achieve this, the rotating electric machine, with a shaft seal device, has inlet and outlet portions, mounted on a rotating shaft, for the seal oil. Also included is a main oil tank in which is stored the seal oil to be supplied to the shaft seal device of the rotating electric machine. In addition, there is also a seal oil clarification tank, which has an inlet portion connected to the outlet portion of the main oil tank and an oil-level adjustment valve. Other components are a degassing pump, with an inlet portion connected to the outlet portion of the seal oil clarification tank; a pressure control valve disposed between the outlet portion of the seal oil clarification tank and an outlet portion of the degassing pump; and a differential pressure control valve disposed between the outlet portion of the degassing pump and the inlet portion of the shaft seal device. |