US20080080988A1 - Pump with electric motor, immersed in the fluid to be pumped - Google Patents

Pump with electric motor, immersed in the fluid to be pumped Download PDF

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Publication number
US20080080988A1
US20080080988A1 US11/580,160 US58016006A US2008080988A1 US 20080080988 A1 US20080080988 A1 US 20080080988A1 US 58016006 A US58016006 A US 58016006A US 2008080988 A1 US2008080988 A1 US 2008080988A1
Authority
US
United States
Prior art keywords
centrifugal wheel
motor
fluid
rolling bearing
casing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/580,160
Other languages
English (en)
Inventor
Fabien Wahl
Francois Danguy
Patrice Fayolle
Jean-Yann Luend
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Safran Aircraft Engines SAS
Original Assignee
SNECMA SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SNECMA SAS filed Critical SNECMA SAS
Assigned to SNECMA reassignment SNECMA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DANGUY, FRANCOIS, FAYOLLE, PATRICE, LUEND, JEAN-YANN, WAHL, FABIEN
Publication of US20080080988A1 publication Critical patent/US20080080988A1/en
Abandoned legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/04—Shafts or bearings, or assemblies thereof
    • F04D29/041—Axial thrust balancing
    • F04D29/0416—Axial thrust balancing balancing pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0653—Units comprising pumps and their driving means the pump being electrically driven the motor being flooded
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/58—Cooling; Heating; Diminishing heat transfer
    • F04D29/586—Cooling; Heating; Diminishing heat transfer specially adapted for liquid pumps
    • F04D29/588—Cooling; Heating; Diminishing heat transfer specially adapted for liquid pumps cooling or heating the machine

Definitions

  • the invention relates to a pump with electric motor, completely immersed, including the motor, in the fluid to be pumped.
  • a pump of this type is, for example, used for pumping a cold liquid such as liquefied natural gas wherein said liquid is used as a fluid for cooling specific elements of the pump, in particular the electric motor, and also for the dynamic axial balancing of the rotational parts.
  • the invention relates, more specifically, to a new arrangement of circuits for the auxiliary circulation of fluid allowing these operations to be carried out.
  • a type of pump in which the suction stage, located in the lower portion of a casing, is surmounted by an electric drive motor accommodated in the same casing. Said casing is designed to be plunged into the fluid to be pumped.
  • a pump of this type can be used for the pumping of liquefied natural gas contained in a tank. The pump is immersed into the liquefied gas, preferably generally vertically down to the bottom of the tank.
  • a pump of this type is, for example, described in U.S. Pat. No. 3,652,186.
  • the common shaft of the electric motor and the suction stage is supported by rolling bearings.
  • the suction stage is followed by a centrifugal wheel connected to the shaft and the structure of said wheel is utilised in order to form an axial balancing system defined by a circuit for fluid circulation, of the actual fluid to be pumped, provided between the centrifugal wheel and the casing.
  • this balancing system relieves the mechanical rolling bearings. A small portion of the pumped fluid is therefore removed in order to feed this balancing system.
  • the pump is able to operate in any position, it is particularly designed to be positioned vertically, with the suction stage at the bottom. This is why, for the remainder of the description, the terms “lower” or “upper” will be used, for example, in order to define the position of one element in relation to another.
  • the invention proposes to optimise the internal auxiliary circulations of fluid in the pump in order to improve the performance levels of the balancing system and those of the cooling stream.
  • the invention therefore relates primarily to an electric motor pump immersed in the fluid to be pumped, comprising a casing intended to be plunged into said fluid and accommodating, on the one hand, at least one centrifugal wheel and, on the other hand, a coaxial electric motor surmounting said centrifugal wheel and comprising a stator which is integral with said casing and a rotor which is integral with a shaft coupled to said centrifugal wheel, a first rolling bearing mounted between said shaft and said casing being installed between said centrifugal wheel and said motor, and an axial balancing system being defined by a fluid circulation circuit provided between said centrifugal wheel and said casing, characterised in that it also comprises at least one fluid cooling circuit, in particular for said motor and/or said first rolling bearing, and in that said supply circuit of said axial balancing system is independent of the or of each cooling circuit.
  • the various fluid circulation auxiliary circuits are easy to install in the pump.
  • the fluid cooling circuit of the electric motor passes through the air gap thereof.
  • the motor is installed in an inner jacket of the casing, defining in said jacket a lower chamber (between said first rolling bearing and the motor) and an upper chamber above the motor.
  • the cooling circuit of the motor comprises inlet orifices formed in the wall of the inner jacket and establishing communication between an evacuation conduit downstream of said centrifugal wheel and the lower chamber. At least one discharge conduit communicating with the upper chamber is provided in order to reintroduce the fluid used for the cooling into the reservoir in which it is stored.
  • the axial balancing system comprises a high-pressure flow space defined between the casing and a lower (front) face of said centrifugal wheel and a low-pressure flow space defined between the casing and an upper (rear) face of this same centrifugal wheel, said low-pressure flow space being limited radially internally by an annular passage forming an axially variable flow restriction.
  • Reinjection channels are provided in said centrifugal wheel between an annular discharge space and the inlet of the centrifugal wheel (where the fluid is at a lower pressure).
  • the annular discharge space is defined around the shaft, radially internally in relation to said annular passage forming the variable flow restriction.
  • FIGURE shows a cross-section and elevation of the pump in accordance with the invention.
  • the illustrated pump comprises a, generally cylindrical, casing 12 accommodating a suction stage 14 and an electric motor 16 .
  • Said motor comprises a stator 18 which is integral with the casing and a rotor 20 equipped with a drive shaft 22 , the axis of which coincides with that of the suction stage.
  • the shaft 22 is mechanically coupled to the suction stage 14 which comprises mainly an Archimedes' screw drive unit, referred to hereinafter as the impeller 26 .
  • the suction stage is surmounted by a centrifugal wheel 28 which is known per se.
  • a diffuser 30 the fixed blades 31 of which are integral with the casing, is installed coaxially between the impeller 26 and the centrifugal wheel 28 .
  • the pump Under normal operating conditions, the pump is designed to be positioned at least approximately vertically and immersed into the fluid to be pumped, with the end 34 of the casing that is closest to the impeller being positioned in the bottom portion.
  • the pumping inlet 35 is defined in the vicinity of this lower end 34 .
  • This shaft and also the rotating parts of the pump which are integral therewith are supported by two rolling ball bearings which are coaxial and set apart on either side of the motor: a first, main, rolling bearing 38 located between the suction stage 14 and the motor 16 , more precisely just above the centrifugal wheel 28 , and a second rolling bearing 40 located above the motor.
  • a first, main, rolling bearing 38 located between the suction stage 14 and the motor 16 , more precisely just above the centrifugal wheel 28
  • a second rolling bearing 40 located above the motor.
  • the inner cage is fixed to the shaft whereas the outer cage is mounted so as to slide in a bore in the casing 12 in such a way that all of the rotating elements of the pump are able to move in the longitudinal direction of the shaft.
  • Said first rolling bearing 38 is installed at the centre of a transverse wall 44 of the casing that separates the suction stage from the motor.
  • the stator of the electric motor is integral with an inner jacket 46 of the casing, which jacket is coaxial with the shaft, in such a way that the air gap 48 of the motor, defined between the exterior of the rotor and the interior of the stator, establishes communication between a lower chamber 50 of said inner jacket (extending between said first rolling bearing and the lower end of the motor) and an upper chamber 52 of said inner jacket, extending between the motor and said second rolling bearing.
  • said inner jacket is filled with the fluid to be pumped.
  • An annular conduit 54 communicating with the outlet 56 of the centrifugal wheel 28 extends around said inner jacket 46 and opens, at its lower portion, into a conduit 58 for evacuating the pumped fluid.
  • a dynamic balancing system 60 defined by a double circuit for the circulation of pumped fluid is provided between the centrifugal wheel and the casing.
  • This balancing system comprises a high-pressure flow space 62 defined between the casing and a lower face of the centrifugal wheel and a low-pressure flow space 64 defined between the casing (more specifically, said transverse wall 44 in which said first rolling bearing is mounted) and an upper face of the centrifugal wheel.
  • the high-pressure flow space 62 defined between said casing and said lower face extends annularly between the high-pressure outlet 56 of the centrifugal wheel and the low-pressure inlet 66 of this same wheel.
  • a first labyrinth seal 68 (or similar calibrated annular flow restriction) is provided between the innermost radial end of this high-pressure flow space and said low-pressure inlet.
  • the inlet of this high-pressure flow space is located at the actual outlet of the centrifugal wheel, without flow restriction.
  • the low-pressure flow space 64 defined between said transverse wall 44 of the casing and said upper face of the centrifugal wheel extends annularly between a second labyrinth seal 70 (establishing calibrated communication with the high-pressure outlet of the centrifugal wheel) and an annular passage 72 forming a variable flow restriction, defined radially internally in relation to said second labyrinth seal 70 .
  • This annular passage is formed between two mutually facing coaxial annular ribs: a rib 74 protruding from the upper face of the centrifugal wheel and a rib 76 protruding from the transverse face of the casing carrying said first rolling bearing.
  • the annular passage forms a variable flow restriction owing to the fact that the shaft, to which the centrifugal wheel is fixed, is movable to a limited extent in its longitudinal direction, as indicated hereinbefore.
  • An annular discharge space 78 is defined radially internally in relation to the annular passage 72 , i.e. between said passage and the shaft. Said space communicates with the low-pressure inlet 66 of the centrifugal wheel via reinjection channels 80 provided in this wheel. Said annular discharge space is thus at all times substantially at the low pressure prevailing at the inlet of the centrifugal wheel.
  • the axial balancing system operates as follows:
  • said second rolling bearing 40 holds the upper end of the shaft and is installed in an axial cavity 84 upwardly extending the upper chamber 52 .
  • At least one discharge conduit 86 (returning to the reservoir into which the pump plunges) communicates with this cavity and therefore with said upper chamber 52 .
  • the or each discharge conduit is equipped with a flow rate calibration element 88 .
  • said second rolling bearing 40 is therefore installed between the upper chamber and the or each discharge conduit.
  • the pressure prevailing in said chamber is therefore substantially equal to the high pressure prevailing at the outlet of the centrifugal wheel.
  • the recess in the first rolling bearing 38 communicates with the annular discharge space 78 via a seal 92 forming a calibrated annular flow restriction.
  • fluid cooling circuits (using a portion of the pumped fluid) are independent of the double fluid circulation circuit of the axial balancing system defined hereinbefore.
  • the fluid supply circuit of the balancing system is basically composed of the high-pressure flow space 62 and the low-pressure flow space 64 as defined hereinbefore.
  • the low-pressure annular discharge space 78 plays no part in the balancing system.
  • the cooling circuit of the motor is established between the inlet orifices 90 formed in the jacket and the flow restriction or restrictions 88 and therefore comprises the lower chamber 50 , the air gap 48 of the motor, the upper chamber 52 (and the axial cavity 84 ), the discharge conduit or conduits 86 and the flow restriction or restrictions 88 .
  • the fluid is reintroduced at the inlet of the pump.
  • the cooling circuit of the first rolling bearing 38 is fed via the orifices 90 and comprises the lower chamber 50 , the seal 92 , the annular discharge space 78 and the reinjection channels 80 bringing the fluid back to the inlet of the centrifugal wheel.
  • the cooling circuit of the second rolling bearing 40 is the same as that of the electric motor 16 .
  • the cooling of the second rolling bearing is less crucial than that of the first rolling bearing and can therefore be combined with that of the electric motor.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Control Of Non-Positive-Displacement Pumps (AREA)
US11/580,160 2006-09-28 2006-10-13 Pump with electric motor, immersed in the fluid to be pumped Abandoned US20080080988A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0653986A FR2906580B1 (fr) 2006-09-28 2006-09-28 Pompe a moteur electrique, immergee dans le fluide a pomper
FR0653986 2006-09-28

Publications (1)

Publication Number Publication Date
US20080080988A1 true US20080080988A1 (en) 2008-04-03

Family

ID=37688389

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/580,160 Abandoned US20080080988A1 (en) 2006-09-28 2006-10-13 Pump with electric motor, immersed in the fluid to be pumped

Country Status (5)

Country Link
US (1) US20080080988A1 (fr)
EP (1) EP1908960A1 (fr)
JP (1) JP2008082318A (fr)
KR (1) KR20080029772A (fr)
FR (1) FR2906580B1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101832275A (zh) * 2010-04-07 2010-09-15 福建天工电机有限公司 一种水冷离心水泵
CN105041671A (zh) * 2015-08-06 2015-11-11 三禾电器(福建)有限公司 一种实现智能调节、观测、统计流量的电泵
US10495099B2 (en) * 2015-11-19 2019-12-03 Grundfos Holding A/S Multistage centrifugal pump with shaft hydraulic force compensation
US11378097B2 (en) * 2015-11-19 2022-07-05 Grundfos Holding A/S Multistage centrifugal pump
US11808268B2 (en) 2020-10-19 2023-11-07 Milwaukee Electric Tool Corporation Stick pump assembly

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5248447B2 (ja) * 2009-08-26 2013-07-31 日機装株式会社 モータポンプ
LU91731B1 (en) * 2010-09-13 2012-03-14 Zenit Internat S A Cooling systems for submersible pumps
KR101272684B1 (ko) * 2011-11-15 2013-06-10 한국항공우주연구원 강제 순환로를 포함하는 베어링 냉각장치 및 상기 베어링 냉각장치를 구비하는 액체연료펌프
KR101381403B1 (ko) * 2012-09-24 2014-04-04 한국항공우주연구원 샤프트를 통한 누설 유체 순환 방식의 원심 펌프
CN104389795A (zh) * 2014-10-31 2015-03-04 湖州三井低温设备有限公司 一种lng潜液泵
KR101812033B1 (ko) * 2016-11-03 2018-01-25 뉴모텍(주) 전이상태에서 발생하는 소음을 방지할 수 있는 온수 순환 펌프
CN111852897B (zh) * 2020-07-10 2021-08-13 中山市伊赫亚家电实业有限公司 一种潜水泵扬程控制方法及其泵结构

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2887062A (en) * 1954-07-01 1959-05-19 Westinghouse Electric Corp Motor pump unit
US3453964A (en) * 1967-08-09 1969-07-08 Air Reduction Casing valve assembly
US3652186A (en) * 1970-05-25 1972-03-28 Carter Co J C Pressure lubricated, cooled and thrust balanced pump and motor unit
US3694110A (en) * 1969-02-21 1972-09-26 Paul Andre Guinard Immersible electric pump arrangements
US4545741A (en) * 1982-05-07 1985-10-08 Hitachi, Ltd. Vertical motor pump
US4889468A (en) * 1987-12-28 1989-12-26 Nikkiso Co., Ltd. Submerged type pump
US20050069434A1 (en) * 2003-09-29 2005-03-31 Nikkiso Co. Ltd. Submerged pump having a bearing lubricated by discharged fluid

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5659214A (en) * 1995-03-03 1997-08-19 Westinghouse Electric Corporation Submersible canned motor transfer pump

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2887062A (en) * 1954-07-01 1959-05-19 Westinghouse Electric Corp Motor pump unit
US3453964A (en) * 1967-08-09 1969-07-08 Air Reduction Casing valve assembly
US3694110A (en) * 1969-02-21 1972-09-26 Paul Andre Guinard Immersible electric pump arrangements
US3652186A (en) * 1970-05-25 1972-03-28 Carter Co J C Pressure lubricated, cooled and thrust balanced pump and motor unit
US4545741A (en) * 1982-05-07 1985-10-08 Hitachi, Ltd. Vertical motor pump
US4889468A (en) * 1987-12-28 1989-12-26 Nikkiso Co., Ltd. Submerged type pump
US20050069434A1 (en) * 2003-09-29 2005-03-31 Nikkiso Co. Ltd. Submerged pump having a bearing lubricated by discharged fluid

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101832275A (zh) * 2010-04-07 2010-09-15 福建天工电机有限公司 一种水冷离心水泵
CN105041671A (zh) * 2015-08-06 2015-11-11 三禾电器(福建)有限公司 一种实现智能调节、观测、统计流量的电泵
US10495099B2 (en) * 2015-11-19 2019-12-03 Grundfos Holding A/S Multistage centrifugal pump with shaft hydraulic force compensation
US11378097B2 (en) * 2015-11-19 2022-07-05 Grundfos Holding A/S Multistage centrifugal pump
US11808268B2 (en) 2020-10-19 2023-11-07 Milwaukee Electric Tool Corporation Stick pump assembly

Also Published As

Publication number Publication date
FR2906580B1 (fr) 2009-01-09
KR20080029772A (ko) 2008-04-03
FR2906580A1 (fr) 2008-04-04
JP2008082318A (ja) 2008-04-10
EP1908960A1 (fr) 2008-04-09

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Legal Events

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AS Assignment

Owner name: SNECMA, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WAHL, FABIEN;DANGUY, FRANCOIS;FAYOLLE, PATRICE;AND OTHERS;REEL/FRAME:018812/0834

Effective date: 20070112

STCB Information on status: application discontinuation

Free format text: EXPRESSLY ABANDONED -- DURING EXAMINATION