Abstract: A bearing interface of an apparatus, the apparatus having a first element and a second element configured to move relative to each other during operation of the apparatus, the first element comprising a first bearing surface configured to engage at least a portion of a second bearing surface of the second element thereby defining a contact zone between the first bearing surface and the second bearing surface, the first bearing surface having at least one recess indented into the first bearing surface, wherein the dimension of the recess in the direction of movement of the second element relative to the first element is less than the dimension of the contact zone in the direction of movement of the second element.

Abstract: A bearing interface of an apparatus, the apparatus having a first element and a second element configured to move relative to each other during operation of the apparatus, the first element comprising a first bearing surface configured to engage at least a portion of a second bearing surface of the second element thereby defining a contact zone between the first bearing surface and the second bearing surface, the first bearing surface having at least one recess indented into the first bearing surface, wherein the dimension of the recess in the direction of movement of the second element relative to the first element is less than the dimension of the contact zone in the direction of movement of the second element.

Abstract: A rotary pump for pumping compressible fluid comprising an eccentrically mounted rotor 20 and a stator 10. The stator 10 comprises a stator inner liner 80 that is free to rotate, driven directly or in response to rotation of the rotor 20 such that the relative velocity between the outer surface of the rotor 20 and the inner surface of the stator 10 is reduced. The vanes 40 are held at each end by sockets 90, 95 in the rotor 20 and stator 10. The vane 40 and socket 90, 95 coupling provides fluid sealing without liquid lubricant. Opposing solid lubricant and hard surfaces are used on contact surfaces between the elements.