A co-rotating scroll machine operable as compressor or expander, comprising:
- a housing (6);
- bearings (5) supported in opposite parts of the housing that are laterally offset from one another,
- first and second parallel spindles (3,4) rotationally supported by the bearings, the first and second spindles extending inwardly of the housing to respective inner ends that are axially spaced-apart from one another and are located adjacent to but laterally offset to one another;
- facing superimposed first and second scroll plates (7,8) mounted transversally on the respective inner ends of the first and second spindles at locations in the vicinity of but spaced from respective centers of the scroll plates;
- and
- a transmission and guidance mechanism (9,10,11) for the first and second scroll plates;
- wherein the transmission and guidance mechanism comprises three transmission and guidance units (9,10) uniformly distributed around the scroll plates towards the periphery thereof,
- each transmission and guidance unit comprising a male element (9) mounted on one of the scroll plates and a facing female element (10) mounted on the facing scroll plate, wherein the radial distances from the center of each scroll plate (7,8) to a center of each transmission and guidance unit (9,10) are equidistant;
- the male element (9) of each transmission and guidance unit (9,10) being received in an opening of the corresponding female element (10) with a play, allowing relative rotational movement of the two scroll plates (7,8) at eccentricity values from 0 to a maximum eccentricity σmax,
- wherein each transmission and guidance unit (9,10) comprises an angularly-displaceable internal ring (17) mounted for angular displacement in the opening of the female element (10), the angularly-displaceable internal ring comprising therein an opening (18) being a slot, and wherein the male element (9) of the transmissions (18) of the angularly-displaceable internal ring (17),
- characterized in that the three male elements (9) of the three transmission and guidance units (9,10) are supported and guided by three respective support elements (13) that are located spaced apart on a common rotatable guide ring (11) that is mounted externally of the scroll plates (7,8) for rotation with the scroll plates about an axis which is parallel to the first and second spindles (3,4) and which is radially offset at the maximum scroll eccentricity, whereby each male element (9) of the three transmission and guidance units (9,10) is supported and guided by its support element (13) on the guide ring (11) during limited movement of the male element (9) in the opening (18) of the angularly-displaceable internal ring (17).