Abstract: A scroll type fluid machine has a swivel scroll (14) driven by a drive bush (101) engaged with a drive shaft bearing portion of the swivel scroll (14) and an eccentric drive pin (25) provided eccentrically on a drive shaft (7). Concentrated surface fatigue caused on the surface of the drive bush (101) is avoided and an elongation of the life of the drive bush (101) is attained by a rotatable cylindrical ring (102) being provided on the outer circumference of the drive bush (101).

Abstract: A scroll fluid machine has a stationary scroll having a first end plate and a first spiral wrap projecting from one side of the first end plate. The first spiral wrap has a tip end. A swivel scroll has a second end plate and a second spiral wrap that projects from the one side of the second end plate. The second spiral wrap has a second end tip, and the first and second spiral wraps are engaged with each other. A first thin steel plate is provided on one side of the end plate between the first end plate and the second tip end. A first thin steel plate has a surface side that faces the second tip end. Further, a second thin steel plate is on one side of the second end plate between the second end plate and the first tip end. The second thin steel plate has a surface side that faces the first tip end. Both of the first and second thin steel plates are provided with conformable layers on the surfaces facing the tip ends.

Abstract: In a low speed rotation, side surfaces of a spiral wrap of a swivel scroll are brought into pressing contact with side surfaces of a spiral wrap of a stationary scroll to thereby keep an air tight condition therebetween. When the orbiting swivelling speed of the swivel scroll exceeds the predetermined level, a predetermined gap is kept between the side surfaces of the spiral wrap of the swivel scroll and the side surfaces of the spiral wrap of the stationary scroll to thereby prevent the abnormal wear of the spiral wraps and to thereby suppress an increase of the consumption power. A counterweight is provided on a drive bush for generating a centrifugal force Fc which is greater than a centrifugal force Fs applied to the swivel scroll during the orbiting swivelling motion of the swivel scroll and which is directed in an opposite direction to that of the centrifugal force Fs. A spring member is provided for biasing the drive bush in a direction .theta. in which the orbiting swivelling radius is increased.

Abstract: An object of the present invention is to decrease the diameter of end plate of a fixed scroll and the diameter of orbiting locus circle of an orbiting scroll, by which the inside diameter of a housing is reduced, thereby the apparatus being made compact. The constitution is such that the center P of the end plate 211 of the fixed scroll 21 lies on the straight line D starting at the wrap end point T of the outermost end of the spiral wrap 212 and passing through the involute unrolled angle position C of the base circle A and at the position shifting one-half the orbiting radius a in the direction reverse to the outermost wrap end of the spiral wrap 212.