Abstract: A radially pressure balanced vane pump includes a housing that defines an inlet port and a discharge port. A cam block disposed within the housing defines a continuous inner surface. A plurality of vanes are supported within rotor slots and rotated above a shaft. Each vane includes a vane tip having a radius with a centerline offset from the centerline of the vane. A pressure biasing the vane into contact with the cam block is distributed over the vane tip radius. Further, the vanes are biased into contact with the inner surface of the cam block by communication of discharge pressure under the vane. The vane tip radius along with the pressure balance between under vane and under vane discharge pressure provide for the use of low cost and easily fabricated ductile steels.

Abstract: A fuel pressurization and pumping system for use in a turbine powered aircraft or the like makes use of the advantages of centrifugal pumps, even in a high pressure mode and includes a centrifugal volute pump (24) having a fuel inlet (28) and fuel outlet (32) along with a regenerative pump (34) having a fuel inlet (36) and a fuel outlet (38). The fuel outlet (32) of the centrifugal volute pump (24) is connected to the fuel inlet (36) of the regenerative pump (34) and a valve (50) is provided for blocking flow from the centrifugal volute pump (24) to the regenerative pump (34). A first pressure regulator (56) is connected to regenerative pump outlet (38) for maintaining pressure thereat at a relatively low elevated level and a second pressure regulator (130) is connected to the regenerative pump outlet (38) for maintaining pressure thereat at a relatively high elevated level. A valve system (66), (90) is provided for selectively disabling the first pressure regulator (56).

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.