Screw pump, screw rotor, method of manufacturing a screw rotor, and use of a screw pump or a screw rotor

A screw pump (100) comprising a housing defining a chamber (62) and two screw rotors (10). Wherein each screw rotor (10) comprises a rotor shaft (11) and at least two displacement elements (12, 14) connected with the rotor shaft (11). Each displacement element (12, 14) having at least one helical protrusion (36, 50). One of the displacement elements (12, 14) is a suction-side dis-placement element (12) arranged in a suction-side section (64) of the chamber (62). Another one of the displacement elements (12, 14) is a pressure-side displacement element (14) arranged in a pressure-side section (68) of the chamber (62). The suction-side displacement element (12) is designed tapering in the conveying direction (22). The clearance between the pressure-side dis-placement element (14) and the pressure-side section (68) of the chamber at least partly decreases in the conveying direction (22). Furthermore, a screw rotor (10), a method of manufacturing a screw rotor (10) and a use of a screw pump (100) or a screw rotor