Abstract: The invention relates to a rotor for a positive displacement rotary pump. The rotor comprises a hub with an aperture and a center axis through aperture and at least 2 lobes radially extending from hub and in a direction essentially perpendicular to the axis of hub. The rotor comprises a core of a first polymer material and a cover of a second polymer material, which second polymer material has a hardness which is lower than the first polymer material. The first and the second polymer materials are connected to each other. The hub or the major part of the hub is preferably provided by the core, whereas at least a part of the lobes is provided by the cover. The invention also relates to a method of providing the rotor and a pump comprising the rotor.

Abstract: The invention relates to a rotor for a positive displacement rotary pump. The rotor comprises a hub with an aperture and a centre axis through said aperture and at least 2 lobes radially extending from said hub and in a direction essentially perpendicular to the axis of said hub. The rotor comprises a core of a first polymer material and a cover of a second polymer material, which second polymer material has a hardness which is lower than the first polymer material. The first and the second polymer materials are connected to each other. The hub or the major part of the hub is preferably provided by the core, whereas at least a part of the lobes is provided by the cover. The invention also relates to a method of providing the rotor and a pump comprising the rotor. The rotor has a high durability and provides an excellent sealing towards inner surface sections of the pumping house as well as towards an engaged rotor.