ROTARY MECHANISM OF GAS EXHAUST PUMP, METHOD FOR PRODUCING SAME, GAS EXHAUST PUMP PROVIDED WITH SAID ROTARY MECHANISM, AND METHOD FOR PRODUCING SAME

摘要

In a gas exhaust pump, there is provided a rotation mechanism that can ensure safe rotation and can greatly reduce the usage of a seal gas. A rotation mechanism of the present invention is formed of a rotating shaft and a seal housing. Between the rotating shaft and the seal housing, there is provided a predetermined gap. On at least one of an outer surface of the rotating shaft and an inner surface of the seal housing, there is provided a PFA film. As to a PFA film on a surface of at least one of the rotating shaft and the seal housing, after coating with PFA the wall surface of the rotation mechanism member defining at least the gap, followed by melting and remelting processes, the PFA film is formed to have a high smoothness on its free surface.