# US 2015/0176591 A1 · Thrust bearings for centrifugal pumps > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0176591 A1 - Document ID: US20150176591A1 - Status: Published application - Kind: A1 - Application number: 14/136,175 - Filed: 2013-12-20 - Published: 2015-06-25 - Earliest claimed: 2013-12-20 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Manmohan Singh GULATI - Web page: https://patentgrep.com/patent/US20150176591A1 ## CPC - F04D 29/056: Bearings - F04D 1/06: Multi-stage pumps (F04D1/02, F04D13/10 take precedence) - F04D 29/0413: {hydrostatic; hydrodynamic thrust bearings} - F04D 29/061: {especially adapted for liquid pumps} - Y02A 20/131: Reverse-osmosis - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## 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. ## Claims ### Claim 1 A bearing assembly for a pump having a casing with an inlet port at a first end of the casing for receiving low pressure process fluid and a discharge port at a second end of the casing for discharging high pressure process fluid, 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 pump 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 fluid communication 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 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 bearing housing where one of the first side lubrication ports meets the central cavity, and configured to direct process 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 bearing housing where one of the second side lubrication ports meets the central cavity, and configured to direct process fluid between one or more of the second side thrust pads and the thrust collar. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 1) 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. ### Claim 6 (depends on 1) The bearing assembly of claim 1 wherein each flow port has a first side lubrication port extending from a first end thereof to the central cavity and a second side lubrication port extending from a second end thereof to the central cavity. ### Claim 7 (depends on 1) 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. ### Claim 8 A pump comprising: a casing having an inlet for receiving process fluid at first end and an outlet for discharging process fluid at a second end; a shaft within the casing rotatable about and axis and moveable along an axial direction; 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 within the casing, the bearing assembly comprising: one or more annular elements coupled to rotate with the shaft, one or more bearing housings coupled to the casing: a plurality of first thrust pads coupled to one of the bearing housings and facing toward the first end of the casing positioned to bear against at least one of the one or more annular elements when the shaft moves along the axial direction from the first end toward the second end; a plurality of second thrust pads coupled to one of the bearing housings and facing toward the second end of the casing positioned to bear against at least one of the one or more annular elements when the shaft moves along the axial direction from the second end toward the first end; and, a plurality of ports through the one or more bearing housings providing flow paths for process fluid to pass through the one or more bearing housings and lubrication paths directing process fluid toward interfaces between the first and second thrust pads and the annular elements. ### Claim 9 (depends on 8) The pump of claim 8 wherein: the one or more annular elements comprise a thrust collar coupled to rotate with the shaft; the one or more bearing housings comprise are located between adjacent impeller stages of the pump, and comprise a first side towards the first end of the casing and a second side toward the second end of the pump casing, and define a central cavity for receiving the thrust collar; and, the plurality of ports comprise a plurality of flow ports arranged around a radial periphery of the central cavity, each of the flow ports providing fluid communication 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 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. ### Claim 10 (depends on 9) The pump of claim 9 wherein the bearing assembly is symmetric about a plane of symmetry perpendicular to an axis of rotation of the thrust collar. ### Claim 11 (depends on 8) 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. ### Claim 12 (depends on 9) The pump of claim 9 wherein the first side and the second side of the bearing housing are constructed in two separate portions. ### Claim 13 (depends on 9) The pump of claim 9 wherein one of the lubrication ports and an associated lubrication nozzle is located between each pair of adjacent thrust pads. ### Claim 14 (depends on 9) The pump of claim 9 wherein each flow port has a first side lubrication port extending from a first end thereof to the central cavity and a second side lubrication port extending from a second end thereof to the central cavity. ### Claim 15 (depends on 9) The pump of claim 9 wherein the one or more bearing housings define 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. ### Claim 16 A desalination system comprising: a pump having 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 along the shaft in a first direction from the first end to the second end and a second direction from the second end to the first end; and a reverse osmosis unit connected to receive the high pressure seawater from the outlet of the pump and output desalinated water and condensate. ### Claim 17 (depends on 16) A desalination system according to claim 16 wherein the pump comprises a plurality of impeller stages arranged sequentially from the first end to the second end, and wherein the bearing assembly is located between a last impeller stage closest to the outlet and a next to last impeller stage. ### Claim 18 (depends on 16) A desalination system according to claim 16 wherein the bearing assembly is symmetric about a plane of symmetry perpendicular to an axis of rotation of the rotatable shaft.