Rotatory pump having a knobbed impeller wheel, and a knobbed impeller wheel therefor

A rotatory pump has a housing (20) and an impeller wheel (40) which is mounted on a driving shaft (30) to rotate integrally therewith. The driving shaft is rotatably supported in the housing. The driving shaft also has a disk (44) disposed to be concentric with the driving shaft. Radially extending blades (46) are directed along the axial direction of the driving shaft (30) being provided on the disk, and the blades, together with the inner wall portions (22a) of the housing (20) which face the blades (46), form flow channels for the fluid to be pumped. At least one raised portion (48) is on each of the radially extending edges (46a) of preferably three blades (46), to bear against the inner wall portions (22a) of the housing (20) which face the blades (46) of the impeller wheel housing.