초록 ▼

A two-stage pump having an internal fluid pathway or cycle for providing cooling to various parts in the pump, such as, an electric motor in the pump, and also for lubricating at least one or a plurality of bearings in the pump. The pump utilized hydrodynamic bearings that are adapted or configured

A two-stage pump having an internal fluid pathway or cycle for providing cooling to various parts in the pump, such as, an electric motor in the pump, and also for lubricating at least one or a plurality of bearings in the pump. The pump utilized hydrodynamic bearings that are adapted or configured to provide various passageways, channels and the like for using the fluid that is being pumped by the pump as lubrication for at least one or a plurality of bearings in the pump.

대표청구항 ▼

What is claimed is: 1. A multistage sealed direct drive pump for pumping a fluid, said pump comprising: an electric motor having a motor shaft; a plurality of impellers mounted on said motor shaft; a housing enclosing said electric motor and said plurality of impellers; a fluid path providing fluid

What is claimed is: 1. A multistage sealed direct drive pump for pumping a fluid, said pump comprising: an electric motor having a motor shaft; a plurality of impellers mounted on said motor shaft; a housing enclosing said electric motor and said plurality of impellers; a fluid path providing fluid communication from a first area associated with a first of said plurality of impellers to a second area associated with a second of said plurality of impellers, said second area being adapted to define a second stage of said multistage sealed direct drive pump; and at least one hydrodynamic bearing for supporting said motor shaft, wherein said at least one hydrodynamic bearing comprising at least one surface and a generally opposing surface, said at least one surface comprising at least one fluid conduit for permitting said fluid to flow from said second area to said first area to lubricate said at least one hydrodynamic bearing and said electric motor, thereby removing heat generated by said electric motor and lubricating said at least one hydrodynamic bearing, wherein said fluid is a liquid refrigerant; said at least one fluid conduit extending across said at least one surface so that when said at least one fluid conduit receives said fluid, said fluid flows through said at least one fluid conduit and between said at least one surface and said generally opposing surface to lubricate said at least one hydrodynamic bearing when said at least one surface rotates relative to said generally opposing surface, and as fluid flows from said second area to said first area, said at least one hydrodynamic bearing being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of said motor shaft. 2. The multistage sealed direct drive pump of claim 1 wherein said electric motor is immersed in said fluid, said pump further comprising a plurality of hydrodynamic bearings, each having at least one fluid conduit for permitting at least some of said fluid to cool said electric motor and to lubricate said plurality of hydrodynamic bearings. 3. The multistage sealed direct drive pump of claim 1 wherein said fluid is conveyed in the fluid path between said plurality of impellers by one or more channels within the housing, said at least one fluid conduit in said at least one hydrodynamic bearing being in fluid communication with said one or more channels. 4. The multistage sealed direct drive pump of claim 1 wherein said fluid is conveyed in the fluid path between said plurality of impellers by one or more channels external to the housing, said at least one fluid conduit in said at least one hydrodynamic bearing being in fluid communication with at least one fluid path interior to said pump. 5. The multistage sealed direct drive pump of claim 1 wherein said at least one hydrodynamic bearing comprises a sleeve portion and a generally planar portion that lies in a plane that is generally radial to an axis of said sleeve portion; said generally planar portion comprising a face having at least one groove extending across said face and said sleeve portion having a sleeve groove extending along said axis, said at least one groove and said sleeve groove being in fluid communication such that fluid may flow through said at least one hydrodynamic bearing. 6. The multistage sealed direct drive pump of claim 1 wherein said at least one hydrodynamic bearing comprises a sleeve portion and a generally planar portion that lies in a plane that is generally radial to an axis of said sleeve portion; said generally planar portion comprising a face having a plurality of face grooves extending across said face and said sleeve portion having a plurality of sleeve grooves extending along said axis, said plurality of face grooves being in fluid communication with said plurality of sleeve grooves, respectively, so that fluid may flow across said face and through said sleeve portion. 7. The multistage sealed direct drive pump of claim 6 wherein said face comprises a plurality of fluid collection areas in fluid communication with said plurality of face grooves, respectively. 8. A multistage pump for pumping a fluid, said multistage pump comprising: a housing; an electric motor mounted in said housing, said electric motor comprising a stator and a rotor mounted on a motor shaft and situated in operative relationship to said stator; a first impeller associated with a first stage area for pressurizing said fluid to a first predetermined level; a second impeller associated with a second stage area that is in fluid communication with said first stage area, said second impeller pressurizing fluid received from said first stage area to a second predetermined level; and a first hydrodynamic bearing assembly associated with said first impeller and a second hydrodynamic bearing assembly associated with said second impeller; said first and second hydrodynamic bearing assemblies being adapted to permit said fluid to flow from said second stage area to said first stage area to lubricate at least one of said first and second hydrodynamic bearing assemblies and said electric motor and to lubricate each of said first and second hydrodynamic bearing assemblies, wherein said fluid is a liquid refrigerant; said first and second hydrodynamic bearing assemblies each comprising a surface and a generally opposing surface, said at least one fluid conduit extending across said surface so that when said at least one fluid conduit receives said fluid, said fluid flows through said at least one fluid conduit and causes each of said first and second hydrodynamic bearing assemblies to be lubricated as fluid flows from said second stage area to said first stage area, each of said first and second hydrodynamic bearing assemblies being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of said motor shaft and as said surface rotates relative to said generally opposing surface. 9. The multistage pump for pumping fluid as recited in claim 8 wherein each of said first and second hydrodynamic bearing assemblies comprises a stationary bearing having a face comprising a pressure-generating geometry for cooperating with a thrust bearing to facilitate providing a supporting film on said face. 10. The multistage pump for pumping fluid as recited in claim 8 wherein each of said first and second hydrodynamic bearing assemblies comprises a stationary bearing having a sleeve for receiving a sleeve journal bearing mounted on said motor shaft, said sleeve comprising a surface having a second pressure-generating geometry for facilitating providing a supporting film of fluid between said sleeve and said sleeve journal bearing. 11. The multistage pump for pumping fluid as recited in claim 9 wherein each of said first and second hydrodynamic bearing assemblies comprises said stationary bearing having a sleeve for receiving a sleeve journal bearing mounted on said motor shaft, said sleeve comprising a surface having a second pressure-generating geometry for facilitating providing a supporting film of fluid between said sleeve and said sleeve journal bearing. 12. The multistage pump for pumping fluid as recited in claim 8 wherein each of said first and second hydrodynamic bearing assemblies comprises a thrust bearing for facilitating rotation of said first and second impellers, respectively, and also a radial sleeve for providing a bearing for facilitating rotation of said motor shaft, each of said first and second hydrodynamic bearings having fluid passageways for delivering fluid to said thrust bearing and a sleeve. 13. The multistage pump of claim 8 wherein said fluid is conveyed in a fluid conduit from said first impeller to said second impeller, each of said first and second hydrodynamic bearing assemblies comprising at least one fluid conduit in fluid communication with one or more channels to permit fluid to flow from said second stage area to said first stage area, thereby lubricating said first and second hydrodynamic bearing assemblies and cooling said electric motor, where said fluid conduit permits flow from said first stage area to said second stage area. 14. The multistage pump of claim 8 wherein said first and second impellers comprise a different diameter to facilitate eliminating or reducing a net axial thrust associated with said motor shaft. 15. The multistage pump as recited in claim 8 wherein said first predetermined level is less than said second predetermined level. 16. The multistage pump as recited in claim 8 wherein each of said first and second hydrodynamic bearing assemblies comprises: a bearing body comprising a sleeve portion and a generally planar portion extending generally radially from said bearing body; a thrust bearing that cooperates with said generally planar portion; a sleeve member for situating on said motor shaft; at least one of said bearing body, said thrust bearing or said sleeve member comprising fluid conduits adapted to cause a hydrodynamic film for lubricating said first and second hydrodynamic bearing assemblies. 17. The multistage pump as recited in claim 16 wherein said at least one of said bearing body comprises a first end and a second end and further comprising a first plurality of channels, each of said first plurality of channels having a first channel area extending generally radially from a first edge associated with said first end and a second channel area extending generally axially to a second edge associated with said second end. 18. The multistage pump as recited in claim 17 wherein said first channel area defines an opening through said first edge associated with said first end and said second channel area defines an opening through said second edge associated with said second end to facilitate providing fluid communication between said first edge and said second edge, respectively. 19. The multistage pump as recited in claim 18 wherein said at least one of said bearing body further comprises a second plurality of channels, each of said second plurality of channels having a third channel area extending generally radially from said first edge associated with said first end and a fourth channel area extending generally axially to said second edge associated with said second end, at least one of said third channel area or said fourth channel area extending through said first edge or said second edge, respectively, while the other of said third channel area or said fourth channel area do not extend through said first edge or said second edge, respectively. 20. The multistage pump as recited in claim 16 wherein said bearing body comprises at least one channel adapted to provide fluid to said sleeve portion and said generally planar portion. 21. The multistage pump as recited in claim 16 wherein said bearing body comprises at least one channel adapted to provide fluid to said sleeve portion and said generally planar portion. 22. The multistage pump as recited in claim 16 wherein said fluid conduits are located in said thrust bearing. 23. The multistage pump as recited in claim 16 wherein said fluid conduits are located in both said thrust bearing and said bearing body. 24. The multistage pump as recited in claim 16 wherein said bearing body and said sleeve member are an integral, one-piece construction. 25. A hermetic pump for pumping a fluid; a housing; an electric motor situated in said housing, said electric motor comprising a motor shaft; at least one impeller mounted on said motor shaft, said at least one impeller comprising a first impeller situated at a first stage area and a second impeller situated at a second stage area, said first and second stage areas being cooled by a fluid passageway through which fluid flows from said first stage area to said second stage area; and at least one hydrodynamic bearing assembly for rotatably supporting said motor shaft, said at least one hydrodynamic bearing assembly comprising a first bearing surface and a second bearing surface; said at least one hydrodynamic bearing assembly being adapted to permit fluid being pumped to flow from said second impeller at said second stage area to said first impeller at said first stage area to cool said electric motor and substantially simultaneously to lubricate said at least one hydrodynamic bearing assembly while said fluid is pumped from said first stage area to said second stage area, wherein said fluid is a liquid refrigerant; said at least one hydrodynamic bearing assembly comprising said at least one fluid conduit that extends across at least one of said first bearing surface or said second bearing surface so that when said at least one fluid conduit receives said fluid, said fluid flows through said at least one fluid conduit and causes said first or second bearing surfaces to be lubricated as fluid flows from said second stage area to said first stage area, said at least one hydrodynamic bearing assembly being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of said motor shaft. 26. The hermetic pump as recited in claim 25 wherein said hermetic pump comprises: a plurality of impellers mounted on said motor shaft; and a plurality of hydrodynamic bearing assemblies adapted to permit the fluid being pumped to cool said electric motor and substantially simultaneously to lubricate said at least one hydrodynamic bearing assembly. 27. The hermetic pump as recited in claim 26 wherein said housing comprises a first area and a second area and said plurality of impellers comprises a first impeller associated with a first area and a second impeller associated with a second area, respectively, said plurality of hydrodynamic bearing assemblies comprising a first bearing assembly for rotatably supporting said motor shaft and providing a first thrust bearing for said first impeller and a second bearing assembly for rotatably supporting said motor shaft and also for providing a second thrust bearing for said second impeller. 28. The hermetic pump as recited in claim 25 wherein said at least one hydrodynamic bearing assembly comprises a body comprising at least one channel for channeling fluid in order to lubricate said at least one hydrodynamic bearing assembly. 29. The hermetic pump as recited in claim 25 wherein said at least one hydrodynamic bearing assembly comprises a body comprising a plurality of grooves for channeling fluid in order to lubricate said at least one hydrodynamic bearing assembly. 30. The hermetic pump as recited in claim 25 wherein said at least one hydrodynamic bearing assembly comprises: a first body member; a first bearing member for situating between said first body member and said motor shaft; a second bearing member for situating between said first body member and said at least one impeller; and at least one of said first body member, said first bearing member or said second bearing member comprising at least one conduit for permitting the fluid to lubricate interfaces between said first body member, said first bearing member and said second bearing member. 31. The hermetic pump as recited in claim 30 wherein said first body member comprises a first end and a second end and further comprising a first plurality of channels, each having a first channel area extending generally radially from a first edge associated with said first end and a second channel area extending generally axially to a second edge associated with said second end. 32. The hermetic pump as recited in claim 31 wherein said first channel area defines an opening through said first edge associated with said first end and said second channel area defines an opening through said second edge associated with said second end to facilitate providing fluid communication between said first edge and said second edge, respectively. 33. The hermetic pump as recited in claim 31 wherein said first body member further comprises a second plurality of channels, each of said second plurality of channels having a third channel area extending generally radially from said first edge associated with said first end and a fourth channel area extending generally axially to said second edge associated with said second end, at least one of said third channel area or said fourth channel area extending through said first edge or said second edge, respectively, while the other of said third channel area or said fourth channel area not extending through said first edge or said second edge, respectively. 34. The hermetic pump as recited in claim 30 wherein said first body member comprises at least one channel adapted to provide fluid to said first bearing member. 35. The hermetic pump as recited in claim 30 wherein said first body member comprises at least one channel adapted to provide fluid to said second bearing member. 36. A multistage pump for pumping a fluid comprising: a housing; an electric motor hermetically sealed within the housing, said electric motor comprising a motor shaft; a first impeller mounted on said motor shaft and associated with a first area in said housing; a second impeller mounted on said motor shaft and associated with a second area in said housing, said second area adapted to define a second stage and said first area adapted to define a first stage of said multistage pump; at least one passageway for permitting fluid communication from said first area to said second area; at least one bearing having at least one lubricating passageway, separate from said at least one passageway, adapted to permit fluid to flow from said second area to said first area such that when said fluid that is being pumped by said multistage pump said fluid lubricates said at least one bearing, where said fluid is a liquid refrigerant; said at least one bearing comprising a bearing surface and an opposing bearing surface, said bearing surface having said at least one lubricating passageway across said bearing surface thereof so that when said at least one lubricating passageway receives said fluid, said fluid flows through said at least one lubricating passageway and lubricates said at least one bearing as fluid flows from said second area to said first area as said bearing surface or said opposed bearing surface is rotated, said at least one bearing being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of said motor shaft. 37. The multistage pump as recited in claim 36 wherein said at least one bearing is a hydrodynamic bearing. 38. The multistage pump as recited in claim 36 wherein said at least one bearing comprises a first bearing assembly associated with said first impeller and a second bearing assembly associated with said second impeller. 39. The multistage pump as recited in claim 38 wherein said first and second bearing assemblies each comprise a thrust bearing member, a stationary member and a sleeve bearing member, at least one of said thrust bearing member, said stationary member and said sleeve bearing member comprises at least one lubricating passageway. 40. The multistage pump as recited in claim 38 wherein said first and second bearing assemblies each comprise a thrust bearing member, an intermediate member and a radial bearing member, a plurality of said thrust bearing member, said intermediate member and said radial bearing member comprises said at least one lubricating passageway. 41. The multistage pump as recited in claim 39 wherein said stationary member comprises at least one lubricating passageway. 42. The multistage pump as recited in claim 39 wherein said thrust bearing member comprises said at lest one lubricating passageway. 43. The multistage pump as recited in claim 40 wherein said at least one lubricating passageway comprises a radial portion that is in fluid connection with an axial portion. 44. A multistage pump comprising: a housing comprising an electric motor having a motor shaft; a first impeller associated with a first area inside said housing; a second impeller associated with a second area inside said housing, said second area being adapted to define a second stage of said multistage pump; a first bearing member mounted in said housing; and first rotating member situated between said first impeller and said first bearing member; said first bearing member and said first rotating member being adapted to define a first hydrodynamic bearing that permits a fluid to flow from said second area to said first area, thereby lubricating said first hydrodynamic bearing, wherein said fluid is a liquid refrigerant; said first bearing member comprising said at least one fluid conduit over a surface of said first bearing member so that when said at least one fluid conduit receives said fluid, said first bearing member becomes lubricated as fluid flows from said second area to said first area and said first bearing member rotates, said first bearing member being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of said motor shaft. 45. The multistage pump as recited in claim 44 wherein said multistage pump further comprises a second bearing member associated with said second impeller; and a second rotating member situated between said second impeller and said second bearing member, said second rotating member being situated between said second impeller and said second bearing member; said second bearing member and said second rotating member being adapted to define a second hydrodynamic bearing. 46. The multistage pump as recited in claim 45 wherein said multistage pump further comprises a third bearing member mounted on said motor shaft; said first bearing member comprising a sleeve portion defining a sleeve area for rotatably receiving said third bearing member, said first bearing member comprising at least one fluid conduit for lubricating an interface between said first bearing member and each of said first rotating member and said third bearing member. 47. The multistage pump as recited in claim 46 wherein multistage pump further comprises a fourth bearing member mounted on said motor shaft; said second bearing member comprising a second sleeve portion defining a second sleeve area for rotatably receiving said fourth bearing member, said second bearing member comprising at least one fluid conduit for lubricating an interface between said second bearing member and each of said second rotating member and said fourth bearing member. 48. The multistage pump as recited in claim 46 wherein said multistage pump further comprises a fourth bearing member mounted on said motor shaft; said second bearing member comprising a second sleeve portion defining a second sleeve area for rotatably receiving said fourth bearing member, said second bearing member comprising at least one fluid conduit for lubricating an interface between said second bearing member and each of a second rotating member and said fourth bearing member. 49. A method for removing heat in a pump having a first stage area and a second stage area that is downstream of said first stage area; creating a pressure differential between said first stage area and said second stage area, with said second stage area being at a higher pressure than said first stage area; providing an internal flow path from said second stage area to said first stage area such that at least a portion of a fluid which flows from said first stage area to said second stage area and is coupled to flow back from said second stage area to said first stage area and as said fluid is being pumped by the pump so that said fluid that flows back from said second stage area to said first stage area lubricates at least one bearing and an electric motor in the pump and to remove heat generated by said electric motor thereby cooling the pump, wherein said fluid is a liquid refrigerant; said at least one bearing comprising said at least one fluid conduit over a surface of said at least one bearing so that when said at least one fluid conduit receives said fluid, said at least one bearing becomes lubricated as fluid flows from said second stage area to said first stage area and by rotation of said at least a portion of said at least one bearing, said at least one bearing being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of a motor shaft. 50. The method as recited in claim 49 wherein the method further comprises the step of: causing fluid flowing along said internal flow path to be sub-cooled between said first and said second stage areas. 51. The method as recited in claim 49 wherein the method further comprises the step of: providing a plurality of hydrodynamic bearings adapted to define at least a portion of said internal flow path. 52. The method as recited in claim 51 wherein said at least one of said plurality of hydrodynamic bearings is a stationary bearing having at least one passageway for directing said fluid along said internal flow path. 53. The method as recited in claim 51 wherein said at least one of said plurality of hydrodynamic bearings is a thrust bearing having at least one passageway for directing said fluid along said internal flow path. 54. A fluid pump having an inlet an outlet comprising: a housing having an electric motor having a motor shaft; a first impeller mounted on said shaft associated with a first stage area; a second impeller mounted on said shaft associated with a second stage area, said second stage area being at a higher pressure than said first stage area; a passageway for permitting a fluid to be pumped from said first stage area to said second stage area; a first bearing assembly for rotatably supporting said first impeller; a second bearing assembly for rotatably supporting said second impeller; at least one flow path for permitting a fluid being pumped by said fluid pump to flow in said housing from said second stage area to said first stage area such that it provides lubrication for said first and second bearing assemblies substantially simultaneously as said fluid is pumped from said first stage area to said second stage area; wherein said fluid is a liquid refrigerant; said first and second bearing assemblies each comprising a first bearing surface and a second bearing surface generally opposed to said first bearing surface, said at least one fluid conduit traversing at least one of said first bearing surface or said second bearing surface so that when said at least one fluid conduit receives said fluid, said first and second bearing assemblies become lubricated as fluid flows from said second stage area to said first stage area and at least one of said first bearing surface or said second bearing surface is rotated, said first and second bearing assemblies being primarily supported with a force resulting from dynamic pressure of said fluid produced by rotation of said motor shaft. 55. The fluid pump as recited in claim 54 wherein at least one flow path comprises a first flow path that permits fluid to flow from said first stage area to said second stage area and out said outlet and a second flow path for permitting at least a portion of said fluid to flow from said second stage area to said first stage area, wherein said second flow path is adapted or arranged to flow across said electric motor to cool said electric motor. 56. The fluid pump as recited in claim 55 wherein said second flow path is adapted or arranged to also provide cooling for said electric motor. 57. The fluid pump as recited in claim 55 wherein each of said first bearing assembly and said second bearing assembly comprises a plurality of hydrodynamic bearings, at least one of said plurality of hydrodynamic bearings comprising at least one passageway for defining at least a portion of said second flow path. 58. The fluid pump as recited in claim 55 wherein fluid flowing along said second flow path remains sub-cooled the entire time it flows along said second flow path.