ROTATION MECHANISM OF GAS EXHAUSTING PUMP AND MANUFACTURING METHOD THEREOF, AND GAS EXHAUSTING PUMP HAVING THE ROTATION MECHANISM AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a smooth film on the rotation axis of a screw pump and the free surface of a housing.SOLUTION: The method includes the successive steps of: preparing a component having a surface including a film of perfluoro alkoxy alkane (PFA) represented by a structural formula 1, exposing the component to an atmosphere at a temperature higher than the melting temperature of PFA, for melting of the free surface region of the film; exposing the component to a temperature lower than the melting temperature of PFA, for solidification of the free surface region, exposing the component to the melting temperature of PFA or a temperature a little higher than the melting temperature of PFA, for re-melting of the free surface region; and lowering the temperature to a temperature sufficiently lower than the melting temperature of PFA.