Metering pump made of plastic

A metering pump (1), made of plastic, comprising two rotors (10), which are coupled to one another via gearwheels (11) and are drivable in opposite directions and which are mounted in a pump housing (5) provided with a suction port (6) and an outlet port (7), wherein each of the rotors (10) has a rotor shaft (12), rotor shaft ends (15) of which are seated in walls (8, 4) of the pump housing (5), and a rotor shaft axis (A), characterized in that each of the rotors (10) has two rotor blade walls (13), which are disposed diametrically on the rotor shaft (12) and onto peripheral ends of which are respectively molded partially cylindrical rotor blade shoes (14), wherein the rotor blade shoes (14) bear slidingly and sealingly against cylindrical inner wall regions of the pump housing (5), on the one hand, and against the rotor blade shafts (13) of the adjacent rotor (10), on the other hand, wherein the pump has an end wall (8) fixedly connected to the pump housing (5) and a detachable end wall (9), wherein the end wall (8) fixedly connected to the pump housing (5) defines both an open bearing sleeve (30) and an outwardly closed bearing sleeve (29), wherein at least one rotor shaft end (15) has a drive coupling part (16), which passes through the pump housing (5) and passes through the end wall fixedly connected to the pump housing (5), wherein both of the rotors (10) are identical and both thus have one of the drive coupling parts (16), and wherein one of the drive coupling parts (16) is seated in the open bearing sleeve (30) and the other drive coupling part (16) is seated in the outwardly closed bearing sleeve (29).