Patent attributes
A casing has a circular cylindrical internal surface delimiting an operating chamber. An orbiting piston is mounted so as to orbit about a chamber axis which is the axis of the internal surface. The orbiting piston has a circular cylindrical external surface, a generatrix of the external surface being adjacent to the said internal surface, and a diametrically opposite generatrix spaced form the internal surface. A vane member has a tip face which faces the external surface of the orbiting piston and which has a length substantially equal to that of the orbiting piston. A linkage connects the vane member to the orbiting piston to keep the tip face adjacent the external surface. At least one of the external and internal surfaces has individual compliant strips distributed around the one surface, which run parallel to one another, and project above the one surface.