PUMP ROTORS

摘要

Pump rotors with improved seizure resistance. Pump rotors (20, 30) for an internal gear pump (10) for sending fluid by sucking and discharging it by variation in the volume of a cell C formed between teeth of both rotors (20, 30) when the rotors (20, 30) rotate while meshing with each other. The internal gear pump (10) has the inner side pump rotor (20) having external teeth (21) formed on it, the outer side pump rotor (30) having formed on it internal teeth (31) meshing with the external teeth (21), and a casing (50) having formed in it a suction port (51) for sucking fluid and a discharge port (52) for discharging the fluid. The pump rotors are formed from an Fe-Cu-C-based sintered material and have a density of not less than 6.6 g/cm³ and not more than 7.1 g/cm³.^{Atleast an outer side pump rotor outer peripheral surface (30b) and both end surfaces orthogonal to the rotating axes of the rotors (20, 30) are non-ground surfaces, and ten-point average roughness Rz of the surfaces is not less than 4 µm and not more than 10 µm.}