Abstract: Difficulties in adapting centrifugal pumps for use as fuel pumps for turbine powered aircraft are avoided in a system including a centrifugal volute pump (22) on a common shaft (18) with a regenerative pump (24). A pressure responsive throttling valve (46) is connected to the inlet (50) of the regenerative pump (24) so as to cause the regenerative pump (24) to provide fuel at a desired, substantially constant pressure while a check valve (80) is connected to the outlet (72) of the centrifugal volute pump (22) to allow flow from the volute (72) but not the reverse. The outlet side of the check valve (80) can also be selectively connected to the outlet (84) of the regenerative pump (24) so that when the pumps are rotating relatively slowly, the regenerative pump (24) will pump fuel at the desired, substantially constant pressure and, as rotational speed increases, the check valve (80) will open when the centrifugal volute pump (22) is pumping fuel at or about the desired substantially constant pressure.

Abstract: The weight and volume of a centrifugal fuel pump ideally suited for use in a fuel system for a turbine engine (12) may be reduced in a construction including a single shaft (10) mounting an inducing impeller (18), an impeller (22) for a regenerative pump, and an impeller (24) for a centrifugal volute pump. Hydrostatic bearings (26), (28) journal the shaft (10) within a pump housing (14) and are provided with fuel under pressure via a conduit (30) connected to the outlets of the regenerative pump and the centrifugal volute pump defined by the impellers (22) and (24), respectively.