Scroll fluid machine having fixed scroll including flange containing groove opposite the orbiting scroll that absorbs deformation due to expansion of the end plate

A scroll fluid machine, comprising:

• a casing supporting a drive shaft;
• a fixed scroll having an end plate, a spiral wrap part provided on the end plate of the fixed scroll, and a flange provided outside the wrap part and fitted to the casing, the flange being a deformation absorbing part including a recessed groove and a projecting part and having radially inner and outer parts that are respectively adjacent to the projecting part;
• and
• an orbiting scroll having an end plate and a spiral wrap part provided on the end plate of the orbiting scroll with a plurality of compression chambers formed in a space up to the wrap part of the fixed scroll, the orbiting scroll provided to perform an orbiting motion,
• wherein the recessed groove is provided in a face of the flange and has an adjacent, opposing relationship to the end plate of the orbiting scroll and the projecting part is provided on a surface of the flange opposite to the face of the flange that faces the orbiting scroll, the radially inner part has a surface that faces away from the orbiting scroll and the radially outer part also has a surface that faces away from the orbiting scroll, the projecting part defines a surface that is disposed in between the radially inner part and the radially outer part and the projecting part projects axially beyond the radially inner part and the radially outer part, and the recessed groove is recessed axially relative to the radially inner part and the radially outer part.