Scroll compressor with rotation preventing apparatus

Claim 1

A scroll compressor comprising: a housing assembly defining an inlet port for a medium to be compressed and an outlet for removal of said medium; an axially extending drive shaft rotatably supported in the housing assembly; a stationary scroll member arranged fixedly in the housing assembly and concentrically to the shaft; a movable scroll member arranged to be freely rotatable about an axis spaced from the axis of the drive shaft; the movable scroll member arranged so as to realize an orbital movement with rotation about its own axis; a plurality of chambers formed between the scroll members during the orbital movement of the movable scroll member, the volume of which is varied in accordance with the orbital movement of the movable scroll member, the inlet port communicating with the chambers for introduction of the medium thereto and the outlet port communicating with the chambers for removal of the medium therefrom; a base plate fixedly connected to the housing and arranged on one side of the movable scroll member; first means for defining a plurality of angularly spaced and outwardly opening first pockets which are integral with the base plate, each of the pockets defining a circular peripheral surface extending parallel to the axis of the shaft and a plate surface extending transverse to the axis of the shaft; second means for defining a plurality of angularly spaced and outwardly opening second pockets which are integral with the movable scroll member, each of the second pockets defining a circular inner surface extending in parallel to the axis of the shaft for support and a plane surface extending transverse to the axis of the shaft, the first and second means being arranged so as to form a plurality of pairs of the first and the second pockets located adjacent to each other; a plurality of connecting means, arranged in each pair of the first and second pockets, for allowing the movable scroll member to realize an orbital movement while being prevented from rotating about its own axis; each of said connecting means comprising a first and a second shoe arranged in the adjacent pair of the first and second pockets, respectively, and a ball arranged between the the first and second shoes having outer peripheral surfaces in contact with the inner peripheral surfaces of the first and second pockets, respectively, for receiving a radial force generated during the orbital movement; and the first and second shoes having, on a first axial end thereof, a first generally plane surface in contact with the plane surfaces of the first and second pockets, respectively, and having, on a second axial end thereof, a second recessed surface with which said ball is in contact for receiving a thrust force.