Regenerative fuel pump having force-balanced impeller

摘要

A pump (10) has a housing containing an internal pumping chamber (30). A fluid inlet (32) and a fluid outlet (34) are spaced arcuately apart about an axis (12), and an impeller (20) within the housing rotates about the axis to pump fluid from the inlet to the outlet. The impeller has mutually parallel opposite faces (40, 42) circumferentially bounded by a vaned periphery (38). The impeller has a pattern of through-holes (46) extending between its faces and the one face that confronts a wall surface of the housing to which the inlet is proximate has, in association with each through-hole, a groove (44) that adjoins and tails circumferentially away from the respective through-hole in a sense opposite the sense in which the impeller rotates to pump fluid from the inlet to the outlet. The groove inclines and provides a reaction surface against which fluid exerts a lifting force to aid in force-balancing the impeller.