US20050175450A1 - Axial-flow pump - Google Patents

Axial-flow pump Download PDF

Info

Publication number
US20050175450A1
US20050175450A1 US11/052,865 US5286505A US2005175450A1 US 20050175450 A1 US20050175450 A1 US 20050175450A1 US 5286505 A US5286505 A US 5286505A US 2005175450 A1 US2005175450 A1 US 2005175450A1
Authority
US
United States
Prior art keywords
axial
impeller
flow pump
flow
pump
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
US11/052,865
Other languages
English (en)
Inventor
Takeshi Okubo
Toshiyuki Osada
Takeshi Sano
Yusuke Miyamoto
Kazuyoshi Miyagawa
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.)
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
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 Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Assigned to MITSUBISHI HEAVY INDUSTRIES, LTD. reassignment MITSUBISHI HEAVY INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MIYAGAWA, KAZUYOSHI, MIYAMOTO, YUSUKE, OKUBO, TAKESHI, OSADA, TOSHIYUKI, SANO, TAKESHI
Publication of US20050175450A1 publication Critical patent/US20050175450A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D1/00—Non-positive-displacement machines or engines, e.g. steam turbines
    • F01D1/02—Non-positive-displacement machines or engines, e.g. steam turbines with stationary working-fluid guiding means and bladed or like rotor, e.g. multi-bladed impulse steam turbines
    • F01D1/04—Non-positive-displacement machines or engines, e.g. steam turbines with stationary working-fluid guiding means and bladed or like rotor, e.g. multi-bladed impulse steam turbines traversed by the working-fluid substantially axially
    • 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
    • F04D29/18—Rotors
    • F04D29/181—Axial flow rotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D3/00—Axial-flow pumps

Definitions

  • the present invention relates to an axial-flow pump having a stable pressure characteristic; for example, an axial-flow pump that can be favorably applied as an artificial heart pump.
  • pumps of various kinds such as pulsating pumps, turbo pumps, and roller pumps, have been used as artificial heart pumps.
  • Turbo pumps are suited for reduction in size.
  • axial-flow pumps are most suited for reduction in size.
  • FIG. 4 is a schematic, sectional, structural view of a conventional axial-flow pump.
  • the axial-flow pump includes a cylindrical housing 1 ; a rotor 3 , which is an impeller and is rotatably supported in the housing 1 in such a manner as to rotate about the axis X of the housing 1 ; and a drive mechanism for rotating the rotor 3 .
  • Rotation of the rotor 3 propels blood under pressure in the axial direction (in FIG. 4 , from right to left).
  • inline arrows show a major blood flow path.
  • a plurality of straightening vanes 4 are projectingly joined to the inner wall surface of the housing 1 at a position located upstream of the rotor 3 .
  • a cylindrical, upstream stationary member 5 is joined to the radially inner edges of the straightening vanes 4 coaxially with the axis X.
  • a plurality of plate-like blades of a diffuser 6 are projectingly joined to the inner wall surface of the housing 1 at a position located downstream of the rotor 3 .
  • a cylindrical, downstream stationary member 7 is joined to the radially inner edges of the blades of the diffuser 6 coaxially with the axis X.
  • the upstream end of the upstream stationary member 5 assumes the form of a round nose so as to smoothly divide and lead blood to the straightening vanes 4 .
  • the downstream end of the downstream stationary member 7 assumes the form of a round nose so as to smoothly merge divided flows of blood from the diffuser 6 .
  • the downstream stationary member 7 contains a motor 10 (drive mechanism), which rotates about the axis X.
  • a rotary shaft 8 is coupled with the motor 10 , so that the rotary shaft 8 rotates about the axis X.
  • a plurality of impeller vanes 9 are projectingly joined to the outer circumferential surface of the rotary shaft 8 .
  • the radially outer edges of the impeller vanes 9 closely oppose the inner wall surface of the housing 1 .
  • the rotary shaft 8 and the impeller vanes 9 constitute the rotor 3 .
  • the rotary shaft 8 and the impeller vanes 9 which constitute the rotor 3 , rotate unitarily about the axis X in the interior of the housing 1 . Accordingly, blood is taken into the housing 1 , its flow is straightened by the straightening vanes 4 , and its pressure is increased by the impeller vanes 9 , whereby the blood becomes blood having dynamic pressure. Then, the diffuser 6 causes most of the blood having dynamic pressure to be restored to blood having static pressure, which is discharged from the housing 1 . In this manner, the axial pump propels blood under pressure.
  • FIG. 5 is a schematic, partial, structural view of the conventional axial-flow pump.
  • the outside diameter of the rotary shaft 8 of the rotor is called a hub diameter Dh; the outside diameter of the impeller vanes 9 of the rotor is called a tip diameter Dt; and their ratio Dh/Dt is called a boss ratio.
  • the boss ratio of the rotor is at most 0.5.
  • the boss ratio tends to be further reduced in order to improve power efficiency, air diffusion efficiency, water supply efficiency, or a like factor (refer to Japanese Patent Application Laid-Open (kokal) Nos. H08-33896 and H05-253592).
  • FIG. 6 is a pair of conceptual views showing how fluid flows along the rotor (impeller) of the conventional axial-flow pump.
  • the boss ratio is low; i.e., when the impeller vanes 9 occupy a large portion of the rotor, reverse flows arise in an outer circumferential portion of the inlet region of the impeller vanes 9 in operation at low flow rate. As a result, the pump head drops.
  • FIG. 7 is a graph showing a flow rate vs. pump head characteristic of the conventional axial-flow pump.
  • a flow rate lower than the design flow rate (a design point of operation) reverse flows in the inlet region cause a drop in pump head (see FIG. 6 ( a )), or the centrifugal effect causes an increase in pump head (see FIG. 6 ( b )).
  • the axial-flow pump exhibits an unstable flow rate vs. pump head characteristic curve.
  • the centrifugal effect tends to greatly increase the non-discharge pump head as compared with the rated pump head (a pump head at the design point of operation).
  • the conventional axial-flow pump has encountered difficulty in application to such a working condition as to require constant discharge pressure regardless of flow rate (for example, use as an artificial heart pump).
  • an object of the present invention is to provide an axial-flow pump having a stable pressure characteristic.
  • the present invention provides an axial-flow pump for propelling fluid under pressure by means of impeller vanes, the axial-flow pump having such a boss ratio as to suppress biased flow of the fluid caused by reverse flows arising in an outer circumferential portion of an inlet region of the impeller vanes and reverse flows arising in an inner circumferential portion of an outlet region of the impeller vanes.
  • the boss ratio is 0.65 to 0.85.
  • the present invention further provides an axial-flow pump comprising a housing, an impeller provided rotatably in the housing, and a drive mechanism for rotating the impeller, and adapted to axially propel fluid under pressure by means of the drive mechanism rotating the impeller.
  • the drive mechanism is fixedly attached to a downstream stationary member which, in turn, is fixedly attached to a diffuser located downstream of the impeller and projecting from an inner wall surface of the housing;
  • the impeller comprises a rotary shaft coupled with the drive mechanism and impeller vanes projecting from the outer circumferential surface of the rotary shaft; and a boss ratio, which is the ratio between the outside diameter of the rotary shaft and the outside diameter of the impeller vanes, is 0.65 to 0.85.
  • the axial-flow pump of the present invention can exhibit a stable pressure characteristic and can reduce the degree of change in discharge pressure associated with a change in flow rate. Accordingly, the axial-pump of the present invention can be applied as, for example, an artificial heart pump, which requires a stable discharge pressure characteristic. Furthermore, application of the axial-flow pump of the present invention as an artificial heart pump can implement an artificial heart pump of reduced size.
  • FIG. 1 is a schematic, partial, structural view of an axial-flow pump according to an embodiment of the present invention
  • FIG. 2 is a pair of conceptual views showing how fluid flows along the rotor (impeller) of the axial-flow pump according to the embodiment;
  • FIG. 3 is a graph showing a flow rate vs. pump head characteristic of the axial-flow pump according to the embodiment
  • FIG. 4 is a schematic, sectional, structural view of a conventional axial-flow pump
  • FIG. 5 is a schematic, partial, structural view of the conventional axial-flow pump
  • FIG. 6 is a pair of conceptual views showing how fluid flows along the rotor (impeller) of the conventional axial-flow pump.
  • FIG. 7 is a graph showing a flow rate vs. pump head characteristic of the conventional axial-flow pump.
  • FIG. 1 corresponds to FIG. 5 and shows a partial, structural arrangement of a diffuser 6 ′, a downstream stationary member 7 ′, a rotary shaft 8 ′, and impeller vanes 9 ′ in the axial-flow pump of the present embodiment.
  • the rotary shaft 8 ′ and the impeller vanes 9 ′ constitute a rotor, and the ratio between the hub diameter Dh of the rotary shaft 8 ′ and the tip diameter Dt of the impeller vanes 9 ′; i.e., the boss ratio Dh/Dt, is 0.65 to 0.85.
  • a boss ratio of 0.65 or higher, preferably 0.7 or higher, is effective for suppressing occurrence of the centrifugal effect and thus for stabilizing the pressure characteristic of an axial-flow pump.
  • the axial-flow pump having such a boss ratio exhibits a stable pressure characteristic over a wide flow rate range including a design flow rate (a design point of operation).
  • the boss ratio increases, the centrifugal effect is suppressed more reliably, and thus a pressure characteristic becomes stabler.
  • increasing the boss ratio reduces the cross-sectional area of a fluid flow path in the axial-flow pump.
  • friction loss increases, causing a drop in pump head.
  • the boss ratio must be 0.85 or less, preferably 0.8 or less.
  • the boss ratio Dh/Dt there are selected the hub diameter Dh of the rotary shaft 8 ′ of the rotor and the tip diameter Dt of the impeller vanes 9 ′ of the rotor.
  • the hub diameter Dh and the tip diameter Dt are selected in the following manners: while the tip diameter Dt is held constant, the hub diameter Dh is increased; while the hub diameter Dh is held constant, the tip diameter Dt is decreased; both of the hub diameter Dh and the tip diameter Dt are increased in such a manner that the hub diameter Dh is increased at a higher rate than the tip diameter Dt; and both of the hub diameter Dh and the tip diameter Dt are decreased in such a manner that the tip diameter Dt is decreased at a higher rate than the hub diameter Dh.
  • a high boss ratio may be selected in any of the above manners in view of the degree of the above-mentioned effect of an increase in the boss ratio, the size of an axial-flow pump, and the cross-sectional area of a fluid flow path in the axial-flow pump.
  • both of the hub diameter Dh and the tip diameter Dt are increased in such a manner that the hub diameter Dh is increased at a higher rate than the tip diameter Dt (third manner), there is obtained an axial-flow pump that is larger in the cross-sectional area of a flow path than the conventional axial-flow pump while having a high boss ratio and a stable pressure characteristic.
  • the size of the axial-flow pump becomes large to some extent.
  • a higher boss ratio can be selected while the cross-sectional area of a flow path in an axial-flow pump is held unchanged.
  • the boss ratio is 0.7
  • the boss ratio is 0.803
  • the larger tip diameter Dt is selected, the size of the axial-flow pump becomes larger to some extent.
US11/052,865 2004-02-10 2005-02-09 Axial-flow pump Abandoned US20050175450A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2004-32900 2004-02-10
JP2004032900A JP2005226457A (ja) 2004-02-10 2004-02-10 軸流ポンプ

Publications (1)

Publication Number Publication Date
US20050175450A1 true US20050175450A1 (en) 2005-08-11

Family

ID=34824239

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/052,865 Abandoned US20050175450A1 (en) 2004-02-10 2005-02-09 Axial-flow pump

Country Status (5)

Country Link
US (1) US20050175450A1 (de)
JP (1) JP2005226457A (de)
CN (1) CN1654825A (de)
AU (1) AU2005200540A1 (de)
DE (1) DE102005006120A1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120082543A1 (en) * 2010-07-30 2012-04-05 Ahsan Choudhuri Axial-Flow Pumps and Related Methods
US8240976B1 (en) * 2009-03-18 2012-08-14 Ebara International Corp. Methods and apparatus for centrifugal pumps utilizing head curve

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103644140B (zh) * 2013-12-05 2015-08-26 江苏大学 一种潜水轴流泵导叶设计方法及潜水轴流泵导叶

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4173796A (en) * 1977-12-09 1979-11-13 University Of Utah Total artificial hearts and cardiac assist devices powered and controlled by reversible electrohydraulic energy converters
US4213745A (en) * 1978-09-11 1980-07-22 Roberts Samuel A Pump for central heating system
US5527159A (en) * 1993-11-10 1996-06-18 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Rotary blood pump

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10288199A (ja) * 1997-04-11 1998-10-27 Sekiyu Kodan 気液混相流用ポンプ

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4173796A (en) * 1977-12-09 1979-11-13 University Of Utah Total artificial hearts and cardiac assist devices powered and controlled by reversible electrohydraulic energy converters
US4213745A (en) * 1978-09-11 1980-07-22 Roberts Samuel A Pump for central heating system
US5527159A (en) * 1993-11-10 1996-06-18 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Rotary blood pump
US5692882A (en) * 1993-11-10 1997-12-02 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Axial pump

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8240976B1 (en) * 2009-03-18 2012-08-14 Ebara International Corp. Methods and apparatus for centrifugal pumps utilizing head curve
US20120082543A1 (en) * 2010-07-30 2012-04-05 Ahsan Choudhuri Axial-Flow Pumps and Related Methods
US20160138596A1 (en) * 2010-07-30 2016-05-19 Board Of Regents, The University Of Texas System Axial-flow pumps and related methods
US9909588B2 (en) * 2010-07-30 2018-03-06 The Board Of Regents Of The University Of Texas System Axial-flow pumps and related methods
US10066627B2 (en) * 2010-07-30 2018-09-04 Board Of Regents, The University Of Texas Systems Axial-flow pumps and related methods

Also Published As

Publication number Publication date
DE102005006120A1 (de) 2005-09-01
CN1654825A (zh) 2005-08-17
JP2005226457A (ja) 2005-08-25
AU2005200540A1 (en) 2005-08-25

Similar Documents

Publication Publication Date Title
JP4674206B2 (ja) 改良されたポンプのインペラ
US3444817A (en) Fluid pump
US5810557A (en) Fan wheel for an inline centrifugal fan
US7186080B2 (en) Fan inlet and housing for a centrifugal blower whose impeller has forward curved fan blades
CN1139183A (zh) 循环泵
US4642023A (en) Vented shrouded inducer
JP2006527804A5 (de)
US5549451A (en) Impelling apparatus
US20050175450A1 (en) Axial-flow pump
US4019829A (en) Centrifugal pump with inducer
JP6737839B2 (ja) インペラ、遠心式流体機械、及び流体装置
JP2001073993A (ja) 遠心式流体機械
JP2000154796A (ja) 羽根車
JP5012060B2 (ja) インデューサ装置
JPS61226596A (ja) タ−ボ分子ポンプ
JPH09195986A (ja) 流体機械の羽根車
JP2001248593A (ja) スクリュー付斜流圧縮機
JP3794543B2 (ja) 遠心圧縮機
JP2009144531A (ja) 遠心ポンプ用羽根車及び遠心ポンプ
JP3276011B2 (ja) 遠心ポンプの羽根車
JP6757461B2 (ja) 遠心圧縮機のインペラ及び遠心圧縮機
JP3225197B2 (ja) 流体機械の旋回失速抑制装置
JPH04209993A (ja) 遠心式圧縮機
JP2000314390A (ja) ポンプ
JPH1182364A (ja) 多段遠心ポンプ

Legal Events

Date Code Title Description
AS Assignment

Owner name: MITSUBISHI HEAVY INDUSTRIES, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:OKUBO, TAKESHI;OSADA, TOSHIYUKI;SANO, TAKESHI;AND OTHERS;REEL/FRAME:016401/0147

Effective date: 20050307

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION