Abstract: An Oldham coupling for connecting two parallel structural parts such as shafts is disclosed wherein an intermediate ring is freely movable between the hubs of the two structural parts intended for connection. The ring carries on its flat sides two lands located at 90.degree. relative to each other and the lands engage corresponding grooves in the hubs. The lands are convex at their friction surfaces and the load bearing walls of the grooves are correspondingly concave to receive the lands. An Oldham coupling of this type is particularly suitable as both a guiding and a rotation inhibiting mechanism for the revolving displacement body of a rotating piston machine of the displacer type.

Abstract: A wobble drive mechanism for a translationally moving structural part includes a wobble rod which is moved by way of a crank drive mechanism. The wobble rod includes a spherical section at one end thereof that is seated in a bearing bush of a crank. At its opposite end, the wobble rod includes a second spherical section that is seated in a stationary structural part. A third spherical section is positioned between the two ends of the wobble rod and is seated in the translationally moving structural part. The spherical sections are supported in hemispherical articulation sockets located in the manner of a mirror image in the two structural parts. A spring device can be provided to ensure full contact of the spherical sections in their respective articulation sockets.

Abstract: In a positive displacement machine for incompressible media, with a working chamber (4) located in a stationary housing (1, 2) and having the configuration of a circular slot, a circular displacer body (8) located in said working chamber, is being held on a disk shaped rotor (3) driven eccentrically relative to the housing. The displacer body contacts the inner and outer circumferential walls of the working chamber at least one sealing line continuously progressing in operation, whereby the medium is conveyed from an inlet (6) to an outlet (7). The inlet is separated from the outlet by a land (5) extending radially in the working chamber (4). For the guidance of the displacer body relative to the housing an Oldham (cross keyed) coupling (9, 10) is provided, and for the circular drive of the displacer body a wobble rod (12, 12') is connected with a driving crank drive (13). In the area of the land (5) the inner and outer work spaces (27, 28) communicate with each other at the inlet ( 6) and the outlet (7).

Abstract: The machine comprises two plate-like supports (9, 12) each provided with a crown of displacement blades (10), respectively displacement chambers (11), engaged into each other, and displaceable into a relative circular translation motion. The drive is implemented by a gear (7-9) at the center of the supports (9, 12), which exerts a force (F.sub.N) on one of the supports (9) at a radially displaceable position, said force presenting a radial component (F.sub.R) and a tangential component (F.sub.T). The direction of the force and the arrangement of the chambers (11) are so selected as to provide for a predetermined static position of the blades (10) in the chambers (11) independently of the wear. Optimum operation conditions are thus obtained with simple design and fabrication. For producing said pump, the plate-like supports are lapped pair-wise when they are in the state of blanks in conditions similar to the operation conditions and are then mounted in the machine.