Rotary seal and/or bearing

A rotary interaction apparatus, comprising:

• a first set of components including a stator and a rotor adapted for rotation about an axis, the first rotor and stator components having facing surfaces which together define a first interface between them, the interface being of a first tapered configuration;
• a first entry chamber for receiving a supply of barrier-liquid;
• one of the facing surfaces defining the first interface provided with a first spiral groove, having an entry-mouth in liquid-flow communication with the first entry-chamber, and having an exit-mouth in liquid-flow communication with a first exit chamber;
• the first-spiral groove disposed as to define plain lands of substantial width between adjacent turns of the first-spiral-groove, the lands creating and supporting a hydrodynamic film of barrier-liquid between the facing surfaces of the first set of components;
• a second set of components including a stator and a rotor adapted for rotation about said axis, the second rotor and stator components having facing surfaces which together define a second interface between them, the second interface being of a second tapered configuration;
• a second entry chamber for receiving a supply of barrier-liquid;
• a second exit-chamber, and a channel for conveying barrier-liquid present in the second exit-chamber out of the second exit-chamber;
• one of the facing surfaces defining the second interface provided with a second spiral groove, having an entry-mouth in liquid-flow communication with the second entry chamber, and having an exit-mouth in liquid-flow communication with the second exit-chamber;
• the second-spiral-groove disposed as to define plain lands of substantial width between adjacent turns of the second-spiral-groove, the lands creating and supporting a hydrodynamic film of barrier-liquid between the facing surfaces of the second set of components;
• the first and second sets of components are arranged in the apparatus with the first and second tapered interfaces thereof in a co-axial, spaced apart position along said axis, the first-exit chamber is in liquid-flow communication with the second-entry chamber, to form a combined intermediate chamber;
• and
• by their rotational sense, the two spiral grooves create a serial pumping action for conveying barrier-liquid in the first-entry chamber towards and into the intermediate chamber, and from the intermediate chamber towards and into the second-exit chamber.