Patent ID: 7789640

Claim:
A fluid machine of the scroll type, comprising: an orbiting scroll having a spiral orbiting wrap and a slide groove having a back side wall surface; a non-orbiting scroll provided with a spiral non-orbiting wrap; a rotating shaft, the rotating shaft having an eccentric portion which is eccentric relative to the axis of rotation of the rotating shaft, wherein the orbiting scroll engages the eccentric portion moving orbitally around the axis of rotation of the rotating shaft; a housing member in which a bearing for supporting the rotating shaft is mounted and which constitutes a non-orbiting member together with a non-orbiting scroll; a columnar shaped pin shaft portion mounted to either one or both of the non-orbiting scroll and the housing member and having a sliding contact surface, formed in a circular arc shape, for sliding contact with the wall surface of the slide groove, the distance from the central axis of the pin shaft portion to the central axis of the rotating shaft being longer than the radius of orbital movement of the orbiting scroll, wherein a portion of the pin shaft nearer to the rotating shaft than the sliding contact surface which slidingly contacts the wall surface of the slide groove is cut away forming a flat side surface, and the flat side surface remains substantially perpendicular to a straight line that passes through the central axis of the pin shaft portion and the central axis of the rotating shaft; wherein rotation of the orbiting scroll is restricted by sliding contact of a wall surface of the slide groove and the sliding contact surface of the pin shaft portion during orbital movement of the orbiting scroll; and wherein the back side wall surface of the slide groove never crossed an inner side surface of the spiral non-orbiting wrap.