Scroll-type fluid machine having a wear-resistant plate

A scroll-type fluid machine comprising:

• a fixed scroll having an end plate, a spiral wrap on said end plate, side surfaces on said spiral wrap a peripheral wall surrounding said spiral wrap and an axial end surface on said peripheral wall;
• an orbiting scroll having an end plate, a spiral wrap on said end plate of said orbiting scroll and having side surfaces engaging with said side surfaces on said spiral wrap on said fixed scroll, one of said scrolls being axially pressed against the other of said scrolls, and an axial end surface on said end plate of said orbiting scroll and having a peripheral portion;
• a surface treatment on said orbiting scroll comprising a coating on at least said side surfaces of said spiral wrap on said orbiting scroll and said axial end surface of said end plate on said orbiting scroll, said coating being selected from the group consisting of an anodic oxidation coating with the pores thereof impregnated with "TEFLON", and alumite treatment;
• a separate hard, wear-resistant plate mounted at least on said peripheral portion of said axial end surface of said end plate on said orbiting scroll, said axial end surface of said end plate on said orbiting scroll being at least partly in sliding contact with said axial end surface on said peripheral wall;
• an axial end surface on said wear-resistant plate facing said axial end surface on said peripheral wall;
• and
• a surface treatment comprising a coating on said peripheral portion of said axial end surface on said end plate of said orbiting scroll where said wear-resistant plate is mounted, so that there is a difference in level within 0.+-.10 .mu.m between said axial end surface of said wear-resistant plate and said axial end surface of said end plate of said orbiting scroll.