摘要 |
<p>There is provided a stator that can ensure safe rotation even if a width of a gap between a screw rotor and a stator is particularly smaller than that of a conventional one and can greatly increase a pumping performance of a pump. A stator of the present invention is formed of a metal and a PFA film is provided on an inner wall surface of a top end surface of a screw rotor. After coating the inner wall surface with PFA, followed by melting and remelting processes, the PFA film is formed to have a high smoothness. The stator is placed with a gap between the inner wall surface and the top end surface. If the PFA film of the present invention is provided in a predetermined manner, the width of the gap can be made significantly smaller than that of a conventional one.</p> |