Rotary pump

A rotary pump comprising:

• a fluid inlet and a fluid outlet;
• a stator comprising a main body and an inner liner rotatably mounted within the main body;
• a rotor comprising a main body eccentrically mounted within the stator;
• vanes extending from the rotor towards an inner surface of the stator inner liner, the stator inner liner, vanes and outer rotor surface defining pump cavities;
• wherein
• the stator inner liner is operable to rotate when the rotor rotates, such that the relative velocity between the vanes and the inner surface of the stator is reduced;
• the vanes are each mounted such that they are received by and extend between a rotor fixing and a stator inner liner fixing, the rotor fixings and stator inner liner fixings being mounted within the rotor and stator inner liner respectively such that the angle of the vanes to the rotor can vary with rotation of the rotor;
• the rotor fixings and the stator inner liner fixings provide fluid sealing between said pump cavities for normal operation without liquid lubricant;
• and
• wherein each of said vanes and at least one of said corresponding rotors and said corresponding stator inner liners having respective contact surfaces, a first of said contact surfaces being a solid lubricant surface and a second of said contact surface being a hard surface so as to provide reduced friction fluid sealing contact without liquid lubricant.