Thrust bearings for centrifugal pumps

Patent metadata

Field	Value
Publication number	US-9874216-B2
Application number	US-201314136175-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 20, 2013
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A bearing assembly for a centrifugal pump is configured to accommodate both forward and reverse axial thrust, and to be lubricated by process fluid. A pump incorporating a dual acting bearing assembly that is lubricated by process fluid and that is located between the final two impeller stages of the pump. A desalination system comprises a pump with an inlet for receiving seawater at a first end, an outlet for discharging high pressure seawater at a second end, one or more impellers coupled to a rotatable shaft between the first end and the second end for increasing a pressure of the seawater, and a bearing assembly lubricated by the seawater for absorbing axial thrust in both directions along the shaft.

First claim

The invention claimed is:

1. A bearing assembly for a pump having a casing with an inlet port at a first end of the casing for receiving a fluid and a discharge port at a second end of the casing for discharging the fluid at a higher pressure, a rotatable shaft moveable in an axial direction with respect to the casing, and a plurality of impellers coupled to rotate with the shaft, the bearing assembly comprising:
a thrust collar coupled to rotate with the shaft;
a bearing housing between adjacent impellers of the pump, the bearing housing having a first side towards the first end of the casing and a second side toward the second end of the casing and defining a central cavity for receiving the thrust collar, the bearing housing comprising:
a plurality of flow ports arranged around a radial periphery of the central cavity, each of the flow ports providing communication of the fluid between the first side of the bearing housing and the second side of the bearing housing; and,
a plurality of first side lubrication ports and second side lubrication ports each having an associated flow port, each first side lubrication port extending from the associated flow port toward the central cavity from the first side and each second side lubrication port extending from the associated flow port toward the central cavity from the second side;
a plurality of first side thrust pads coupled to the first side of the bearing housing and having a bearing surface facing toward the central cavity;
a plurality of second side thrust pads coupled to the second side of the bearing housing and having a bearing surface facing toward the central cavity;
a plurality of first side lubrication nozzles, each coupled to the bearing housing where one of the first side lubrication ports meets the central cavity, and configured to direct some of the fluid between one or more of the first side thrust pads and the thrust collar; and
a plurality of second side lubrication nozzles each coupled to the bearing housing where one of the second side lubrication ports meets the central cavity, and configured to direct some of the fluid between one or more of the second side thrust pads and the thrust collar.

2. The bearing assembly of claim 1 wherein the bearing assembly is symmetric about a plane of symmetry perpendicular to an axis of rotation of the thrust collar.

3. The bearing assembly of claim 1 wherein the bearing housing is between a last impeller closest to the discharge port and a next to last impeller.

4. The bearing assembly of claim 1 wherein the bearing housing is constructed in two separate portions with a first portion comprising the first side and a second portion comprising the second side.

5. The bearing assembly of claim 1 wherein one of the lubrication ports and an associated lubrication nozzle is located between each pair of adjacent thrust pads.

6. The bearing assembly of claim 1 wherein each of the flow ports has one of the first side lubrication ports extending from a first end thereof to the central cavity and one of the second side lubrication ports extending from a second end thereof to the central cavity.

7. The bearing assembly of claim 1 wherein the bearing housing has an annular cavity positioned around the radial periphery of the central cavity, the annular cavity providing fluid communication between the plurality of flow ports and the central cavity.

8. A pump comprising:
a casing having an inlet port for receiving a fluid at a first end and a discharge port for discharging the fluid at a higher pressure at a second end;
a shaft within the casing rotatable about an axis and moveable along an axial direction with respect to the casing;
a plurality of impeller stages, each impeller stage comprising an impeller coupled to rotate with the shaft and a diffuser held stationary within the casing;
a bearing assembly comprising:
a thrust collar coupled to rotate with the shaft;
a bearing housing between adjacent impellers of the pump, the bearing housing having a first side towards the first end of the casing and a second side toward the second end of the casing and defining a central cavity for receiving the thrust collar, the bearing housing comprising:
a plurality of flow ports arranged around a radial periphery of the central cavity, each of the flow ports providing communication of the fluid between the first side of the bearing housing and the second side of the bearing housing; and,
a plurality of first side lubrication ports and second side lubrication ports each having an associated flow port, each first side lubrication port extending from the associated flow port toward the central cavity from the first side and each second side lubrication port extending from the associated flow port toward the central cavity from the second side;
a plurality of first side thrust pads coupled to the first side of the bearing housing and having a bearing surface facing toward the central cavity;
a plurality of second side thrust pads coupled to the second side of the bearing housing and having a bearing surface facing toward the central cavity;
a plurality of first side lubrication nozzles, each coupled to the bearing housing where one of the first side lubrication ports meets the central cavity, and configured to direct some of the fluid between one or more of the first side thrust pads and the thrust collar; and
a plurality of second side lubrication nozzles each coupled to the bearing housing where one of the second side lubrication ports meets the central cavity, and configured to direct some of the fluid between one or more of the second side thrust pads and the thrust collar.

9. The pump of claim 8 wherein the bearing assembly is symmetric about a plane of symmetry perpendicular to an axis of rotation of the thrust collar.

10. The pump of claim 8 wherein the bearing assembly is positioned between a last impeller stage closest to the outlet and a next to last impeller stage.

11. The pump of claim 8 wherein the first side and the second side of the bearing housing are constructed in two separate portions.

12. The pump of claim 8 wherein one of the lubrication ports and an associated lubrication nozzle is located between each pair of adjacent thrust pads.

13. The pump of claim 8 wherein each of the flow ports has one of the first side lubrication ports extending from a first end thereof to the central cavity and one of the second side lubrication ports extending from a second end thereof to the central cavity.

14. The pump of claim 8 wherein the bearing housing has an annular cavity positioned around the radial periphery of the central cavity, the annular cavity providing fluid communication between the plurality of flow ports and the central cavity.

Assignees

• Gen Electric

Inventors

• Gulati Manmohan Singh

Classifications

• F04D29/0413

  hydrostatic; hydrodynamic thrust bearings · CPC title

• F04D29/041

  Axial thrust balancing · CPC title

• F04D1/06 Primary

  Multi-stage pumps (F04D1/02, F04D13/10 take precedence) · CPC title

• F04D29/061

  especially adapted for liquid pumps · CPC title

• F04D29/056 Primary

  Bearings · CPC title