US 6,692,318 B2 · Mixed flow pump

Abstract

The present invention relates to propulsion and hydraulic systems having a co-axial design wherein the inlet section, impeller section, and outlet section of a mixed flow pump system all have a common centerline axis or axis of rotation. The mixed flow pump system includes an outer casing and a central body disposed co-axially within the outer casing. A pump impeller is rotatably connected to the central body for imparting hydraulic energy to the fluid flowing through the mixed flow pump system. The mixed flow pump system may also include inlet flow conditioning vanes for conditioning an inlet flow of fluid to the mixed flow impeller for improving the cavitation performance and/or acoustic performance of the pump module. Stator vanes are provided for connecting the central body to the outer casing and to remove any swirl velocity from the fluid flow exiting the mixed flow pump impeller. The mixed flow pump system exhibits improved resistance to cavitation due to the use of one or more of inlet flow conditioning vanes and low RPM motors for rotating the mixed flow pump impeller. The invention has applications in a variety of applications, including propulsion and hydraulic applications. For example, the invention may be used for the propulsion of marine vehicles, such as submerged crafts, weapons and unmanned underwater vehicles (UUVs) of various sizes and speed requirements. The mixed flow pump may also be applied to non-marine applications such as hydraulic applications, chemical distribution systems, and medical devices.

Claims30

Dependent claims

A co-axial mixed flow pump comprising:

an outer casing having a longitudinal centerline axis;
a central body aligned co-axially within said outer casing along said longitudinal centerline axis;
an axial forward looking inlet formed along said longitudinal centerline axis for receiving a flow of fluid;
a mixed flow pump having a rotating impeller mounted to a forward end of said central body, said mixed flow pump impeller comprising:
a hub;
a plurality of blades extending outward from said hub;
and
a plurality of flow passages formed between adjacent blades,
wherein said mixed flow pump impeller rotates about said longitudinal centerline axis to draw a flow of fluid into said mixed flow pump impeller through said inlet and imparts energy to said fluid flow;
an annular passageway formed between said outer casing and said central body on a downstream side of said mixed flow impeller for receiving said fluid flow exiting said mixed flow impeller, said annular passageway being aligned axially;
a plurality of stator vanes disposed between and connecting said outer casing and said central body to condition said flow exiting said mixed flow pump impeller to flow generally in the axial direction;
an axial rearward looking outlet formed along said longitudinal centerline axis for discharging said flow of fluid from said mixed flow pump.

9 more elements

A mixed flow pump for inputting hydraulic energy to a fluid flowing therethrough comprising:

an outer casing aligned axially from a forward end to a rearward end, said outer casing comprising an inlet section, an impeller section, and an outlet section;
said inlet section comprising:
an axially aligned inlet opening at said forward end;
an axially aligned inlet duct having a generally increasing cross-sectional area from a first end of said inlet duct proximal said inlet opening to a second end of said inlet duct;
said impeller section connected to a downstream end of said inlet section, said impeller section comprising:
an axially aligned impeller inlet connected to said second end of said inlet section;
an impeller sweep area having a generally increasing circular cross-sectional area from said impeller inlet to an impeller outlet;
said outlet section connected to a downstream end of said impeller section, said outlet section comprising:
an axially aligned inlet at a forward end of said outlet section connected to said impeller outlet;
an axially aligned outlet duct having a generally decreasing cross-sectional area from said outlet section inlet to a discharge;
a central body disposed within and co-axial with said outer casing, comprising:
a stationary hub disposed within said outlet section;
a mixed flow pump impeller rotatably mounted to a forward end of said hub and in said impeller section for drawing a flow of fluid through said inlet duct and into said mixed flow pump impeller;
an annular passageway formed between said central body and said outer casing and in said outlet section;
a stator blade assembly disposed between and connecting said central body and said outer casing to provide structural support for said central body, to remove any swirl velocity from said fluid flow exiting said mixed flow pump impeller, and to convert kinetic energy contained within the swirl velocity to pressure;
and
a drive motor for rotating said mixed flow pump impeller.

14 more elements

A co-axial propulsion system comprising:

an outer casing comprising ducting having a longitudinal centerline, said ducting for containing and guiding a fluid flow within said co-axial propulsion system;
a forward looking, axial inlet opening of said outer casing centered about said longitudinal centerline for receiving an axial flow of fluid from one of an internal fluid system and an exterior fluid operating environment into an interior of said co-axial propulsion system;
a rearward looking, axial outlet opening of said outer casing centered about said longitudinal centerline for discharging an axial flow of fluid from said interior of said co-axial propulsion system to one of said internal fluid system and said exterior fluid operating environment;
wherein said ducting extends axially and connects said inlet opening and said outlet opening;
a central body disposed co-axially within said outer casing;
a mixed flow pump impeller rotatably mounted to said central body and disposed co-axially about said longitudinal centerline, wherein an axis of rotation of said mixed flow pump impeller is co-axial with said longitudinal centerline;
an annular passageway defined between said outer casing and said central body, said annular passageway being oriented co-axially about said longitudinal centerline;
a plurality of stator vanes disposed co-axially about said longitudinal centerline and extending radially between said outer casing and said central body and extending through said annular passageway, said stator vanes supporting said central body within said outer casing;
and
wherein said stator vanes are configured to remove swirl velocity from said fluid flow exiting said mixed flow impeller and straightening said fluid flow to flow in an axial direction toward said outlet opening.

7 more elements

Dependencies are inferred from the claim text.

Mixed flow pump

Life of this patent

Mixed flow pump

Life of this patent

Abstract

Claims30