Scroll Fluid Machine

A scroll fluid machine comprising:

• a scroll unit which is composed of a fixed scroll and a movable scroll each having spiral wraps formed on base surfaces of base plates thereof, the spiral wraps opposing each other, and in which a working chamber of a working fluid is formed between the wraps of the fixed scroll and the movable scroll by an orbital motion of the movable scroll about an axis of the fixed scroll;
• a frame having a pedestal which orbitably supports the movable scroll at an outer peripheral portion of a rear surface on the opposite side from the base surface of the movable scroll;
• and
• a support mechanism which orbitably supports the movable scroll at a central portion of the rear surface of the movable scroll,
• wherein the support mechanism includes:
• a boss provided on the rear surface of the movable scroll;
• an eccentric bush slidably and rotatably fitted in the boss;
• a slide bush placed in a receiving hole formed in the eccentric bush such that the slide bush is movable in a direction of eccentricity of the eccentric bush;
• a fixed shaft which is provided protruding from a bottom surface of the frame and which is slidably and rotatably inserted in an insertion hole formed in the slide bush;
• and
• a spring which is interposed between the slide bush in the receiving hole and the eccentric bush and which biases the slide bush in a direction in which the slide bush moves,
• a spring holding section and engagement projection which protrudes outward are formed on the slide bush, and
• the engagement projection engages with the eccentric bush in a state in which the slide bush has been placed in the receiving hole and then moved by a biasing force of the spring, thereby preventing the slide bush from falling off the receiving hole, and the spring holding section prevents the spring from falling off the receiving hole.