| 摘要 |
PURPOSE:To eliminate management for control of a pressure and maintenance of pump performance by a method wherein a pressure control unit having a pressure controller, a pressure sensor, and a control valve is incorporated in a vacuum pump body. CONSTITUTION:A pressure control unit 1 is mounted to the upper part of a pump body 3 of an oil-sealed rotary vacuum pump. The pressure of an intake air port 4 is measured by a pressure sensor 6, and is compared with a value preset by a pressure controller 7. When a difference is produced therebetween, an inactive gas flow rate control valve 8 is regulated, and through regulation of a flow rate of gas through an N2 feed port 9 to the suction side, the pressure of the intake air port 4 is specified. This constitution eliminates management for control of a pressure by means of a processing device body and maintenance of pump performance. |
