WO2004005721A1 - A regenerative fluid pump and stator for the same - Google Patents

A regenerative fluid pump and stator for the same Download PDF

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Publication number
WO2004005721A1
WO2004005721A1 PCT/GB2003/002904 GB0302904W WO2004005721A1 WO 2004005721 A1 WO2004005721 A1 WO 2004005721A1 GB 0302904 W GB0302904 W GB 0302904W WO 2004005721 A1 WO2004005721 A1 WO 2004005721A1
Authority
WO
WIPO (PCT)
Prior art keywords
channel portions
pumping channel
channels
pump
rotor blades
Prior art date
Application number
PCT/GB2003/002904
Other languages
French (fr)
Inventor
Ian David Stones
Original Assignee
The Boc Group Plc
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 The Boc Group Plc filed Critical The Boc Group Plc
Priority to AU2003244835A priority Critical patent/AU2003244835A1/en
Publication of WO2004005721A1 publication Critical patent/WO2004005721A1/en

Links

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
    • F04D23/00—Other rotary non-positive-displacement pumps
    • F04D23/008—Regenerative pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D5/00—Pumps with circumferential or transverse flow
    • F04D5/002—Regenerative pumps
    • F04D5/003—Regenerative pumps of multistage type
    • F04D5/005—Regenerative pumps of multistage type the stages being radially offset

Definitions

  • the present invention relates to a regenerative fluid pump.
  • a regenerative fluid pump known hereto is shown schematically in Figure 3.
  • the prior art pump 100 is a radial regenerative fluid pump which compresses fluid on a fluid flow path extending between an inlet 102 and an outlet 104 of the pump.
  • the pump comprises a plurality of concentric circumferential channels 105 (represented by concentric circles in Figure 3).
  • the channels comprise respective pumping channel portions 106 along which fluid compression takes place and which together form a fluid flow path.
  • the channels further comprise respective stripper channel portions 108 (shown in broken lines) which allow the passage of the pump's rotor blades from the outlets of respective pumping channel portions 106 to the inlets thereof.
  • fluid enters the pump inlet 102 and is compressed by the rotor blades in the radially outermost, or first, pumping channel portion 106a.
  • fluid is diverted by a diversion channel 110 (shown by arrows in Figure 3) to the inlet of a radially inner, or second, pumping channel portion 106b.
  • rotor blades having passed along the outermost pumping channel move into the radially outermost, or first, stripper channel portion 108a and back to the inlet of the outermost pumping channel 106a.
  • stripper channel portion is manufactured so that there are small running clearances between the walls of the stripper channels and rotor blades passing therethrough.
  • Figure 4 is a cross-sectional view of a stator 112 for the regenerative fluid pump shown schematically in Figure 3.
  • Figure 4 is taken along line IV in Figure 3. It should be noted that the schematic view in Figure 3 shows only four pumping stages whereas the stator in Figure 4 is for a pump having six pumping stages.
  • Line IV is a radial line extending from centre C and passing through a number of pumping channel portions 106. Line IV does not pass through any through stripper channel portions 108.
  • the pumping channel portions have a rounded section 114 along which fluid flows during use and a straight sided section 116 for receiving rotor blades passing along the pumping channel portion 106.
  • Rotor blades 118 extend into the rounded section and for explanatory purposes the position of the rotor blades is shown in dotted lines.
  • the straight sided sections closely fit adjacent the rotor blades whereas the walls of the rounded sections are spaced from the rotor blades.
  • the radial width of the rounded sections of the pumping channel portions is an important limiting factor, as is the gap G between the rounded sections. Gap G must be of a minimum width such that the integrity of the pump is maintained during use at high fluid pressures.
  • the present invention provides a regenerative fluid pump comprising a rotor having rotor blades, and a stator comprising a plurality of concentric channels which comprise pumping channel portions along which said rotor blades move for compressing fluid between respective inlets and respective outlets of the pumping channel portions and stripper channel portions for allowing said rotor blades to pass from said outlets to said inlets of the pumping channel portions, wherein pumping channel portions of two directly adjacent channels do not circumferentially overlap.
  • the present invention also provides a stator for a regenerative fluid pump comprising a rotor having rotor blades for compressing fluid on a fluid flow path extending between a pump inlet and a pump outlet, the stator comprising a plurality of concentric channels which comprise pumping channel portions along which said rotor blades move for compressing fluid between respective inlets and respective outlets of the pumping channel portions and stripper channel portions for allowing said rotor blades to pass from said outlets to said inlets of the pumping channel portions, wherein pumping channel portions of two directly adjacent channels do not circumferentially overlap.
  • Figure 1 is a schematic representation of a regenerative fluid pump embodying the present invention
  • Figure 2 is a cross-sectional view of a stator for the regenerative fluid pump shown schematically in Figure 1 taken along line II;
  • Figure 3 is a schematic view of a prior art regenerative fluid pump
  • Figure 4 is a cross-sectional view of a stator for the regenerative fluid pump shown schematically in Figure 3 taken along line IV.
  • a regenerative fluid pump 10 which comprises four pumping stages although, more or less stages may be provided, as required.
  • Pump 10 comprises a rotor having rotor blades for compressing fluid on a fluid flow path extending between a pump inlet 12 and a pump outlet 14, and a stator comprising a plurality of concentric channels 16 which comprise pumping channel portions 18 along which said rotor blades move for compressing said fluid between inlets and outlets of the pumping channel portions and stripper channel portions 20 which allows movement of said rotor blades from said outlets to said inlets of the pumping channel portions.
  • Diversion channels 22 (indicated by arrows in Figure 1) divert fluid between the pumping channel portions in the same way as described above in relation to Figure 3.
  • the pumping channel portions 18 of any two directly adjacent concentric channels 16 do not circumferentially overlap so that the stripper channel portions 20 are directly adjacent the pumping channel portions 18, over the circumferential extent of the pumping channel portions.
  • radial cross-sections taken through the stator reveal that the stripper channel portions and the pumping channel portions alternate from the centre of the stator radially outwards. This does not apply to a cross-section taken at the diversion channels 22 where the channel portions do not alternate.
  • FIG. 2 Shown in Figure 2 is a cross-section of a stator 24 for the pump 10 shown schematically in Figure 1.
  • Figure 2 shows stator 24 as viewed along line II.
  • Stator 24 is provided with six concentric channels 16 (i.e. is suitable for a six stage pump) whereas only four pumping stages are shown in Figure 1.
  • stripper channel portions 20 alternate with pumping channel portions 18 along radial line II from centre C.
  • the stripper channel portions are thinner than the pumping channel portions because the stripper channel portions are designed to closely match the shape of the rotor blades to reduce the amount of fluid which is able to seep along the stripper channel portions during use.
  • the alternating characteristic of the pumping channel portions 18 and the stripper channel portions enables the overall width of the concentric channels 16 W to be reduced relative to the width W as in the prior art. Accordingly, stator 24 allows a regenerative fluid pump of smaller overall dimensions as compared with the prior art.
  • the concentric channels 16 comprise radially inner directly adjacent channels 16c, 16d and radial outer directly adjacent channels 16a, 16b, and the pumping channel portions 18a, 18b of the radially outer channel 16a, 16b are wider than the pumping channel portions 18c, 18d of the radially inner concentric channels 16c, 16d. This arrangement aids compression of fluid as it is directed radially inwardly.
  • pumping channel portions 18a, 18b of the two directly adjacent radially outer channels 16a, 16b do not circumferentially overlap since these pumping channel portions are relatively wide, whereas pumping channel portions 18c, 18d of the two directly adjacent radially inner channels 16c, 16d circumferentially overlap since these pumping channel portions are relatively thin and there is little reduction overall width to be gained by angular alignment of pumping channel portions 18c, 18d with stripper channel portions 20c, 20d. It will also be appreciated that an arrangement in which the pumping channel portions of no more than two directly adjacent channels do not overlap will still contribute to a reduction in overall width of the pump.
  • Figure 1 shows an arrangement in which the stripper channel portions 20 and pumping channel portions 18 extend for about 180° of the circumference of the respective concentric channels 16.
  • the present invention is not limited to such an arrangement.
  • the pumping channel portions 18 may extend more or less than 180° for each concentric channel 16 provided that the stripper channel portions of each concentric channel are adjacent the pumping channel portions of an adjacent concentric channel 16, allowing the above described reduction in the size of the stator 24.
  • stator size reduction may be achieved provided that the pumping channel portion and the stripper channel portion of at least one of said concentric channels are adjacent the stripper channel portion and the pumping channel portion, respectively, of an adjacent said concentric channel over the circumference of said at least one and said adjacent channels.
  • the alternating relationship of the pumping channel portions 18 and the stripper channel portions 20 need not be present over the entire radial extent of the stator.
  • Figure 1 shows a radial regenerative fluid pump which allows the radial width of the stator to be reduced.
  • the present invention is also relative to an axial regenerative fluid pump, although, with an axial pump, the arrangement would allow the axial length of the pump to be reduced.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

A regenerative fluid pump (10) comprises a rotor having rotor blades for compressing fluid on a fluid flow path extending between a pump inlet (12) and a pump outlet (14), and a stator comprising a plurality of concentric channels (16) each of which comprises: a pumping channel portion (18) along which said rotor blades move for compressing said fluid between an inlet and an outlet of the pumping channel; and a stripper channel portion (20) which allows movement of said rotor blades from said outlet to said inlet of the pumping channel portion. Diversion channels (22) divert fluid between the pumping channel portions. The pumping channel portions (18) of any two directly adjacent concentric channels (16) do not circumferentially overlap so that the stripper channel portions (20) are directly adjacent the pumping channel portions (18), over the circumferential extent of the pumping channel portions.

Description

A REGENERATIVE FLUID PUMP AND STATOR FOR THE SAME
The present invention relates to a regenerative fluid pump.
A regenerative fluid pump known hereto is shown schematically in Figure 3. The prior art pump 100 is a radial regenerative fluid pump which compresses fluid on a fluid flow path extending between an inlet 102 and an outlet 104 of the pump. The pump comprises a plurality of concentric circumferential channels 105 (represented by concentric circles in Figure 3). The channels comprise respective pumping channel portions 106 along which fluid compression takes place and which together form a fluid flow path. The channels further comprise respective stripper channel portions 108 (shown in broken lines) which allow the passage of the pump's rotor blades from the outlets of respective pumping channel portions 106 to the inlets thereof.
In operation, fluid enters the pump inlet 102 and is compressed by the rotor blades in the radially outermost, or first, pumping channel portion 106a. At the outlet of the first pumping channel portion, fluid is diverted by a diversion channel 110 (shown by arrows in Figure 3) to the inlet of a radially inner, or second, pumping channel portion 106b. At this time, rotor blades having passed along the outermost pumping channel move into the radially outermost, or first, stripper channel portion 108a and back to the inlet of the outermost pumping channel 106a. Although most fluid is diverted radially inwardly by the diversion channel there is some seepage through the stripper channel portion due to the action of the rotor blades and the pressure gradient from the inlet to the outlet of the stripper channel portion. The stripper channel portion is manufactured so that there are small running clearances between the walls of the stripper channels and rotor blades passing therethrough.
Fluid continues along the fluid flow path in the same manner as described above until it reaches the pump outlet 104. Figure 4 is a cross-sectional view of a stator 112 for the regenerative fluid pump shown schematically in Figure 3. Figure 4 is taken along line IV in Figure 3. It should be noted that the schematic view in Figure 3 shows only four pumping stages whereas the stator in Figure 4 is for a pump having six pumping stages.
Line IV is a radial line extending from centre C and passing through a number of pumping channel portions 106. Line IV does not pass through any through stripper channel portions 108. The pumping channel portions have a rounded section 114 along which fluid flows during use and a straight sided section 116 for receiving rotor blades passing along the pumping channel portion 106. Rotor blades 118 extend into the rounded section and for explanatory purposes the position of the rotor blades is shown in dotted lines. The straight sided sections closely fit adjacent the rotor blades whereas the walls of the rounded sections are spaced from the rotor blades.
Reduction in size of the stator and thus the size of the pump is limited by a number of factors. In particular, the radial width of the rounded sections of the pumping channel portions is an important limiting factor, as is the gap G between the rounded sections. Gap G must be of a minimum width such that the integrity of the pump is maintained during use at high fluid pressures.
It is desirable to reduce the width W that the concentric channels occupy and thus reduce the size of the regenerative fluid pump. The present invention provides a regenerative fluid pump comprising a rotor having rotor blades, and a stator comprising a plurality of concentric channels which comprise pumping channel portions along which said rotor blades move for compressing fluid between respective inlets and respective outlets of the pumping channel portions and stripper channel portions for allowing said rotor blades to pass from said outlets to said inlets of the pumping channel portions, wherein pumping channel portions of two directly adjacent channels do not circumferentially overlap.
The present invention also provides a stator for a regenerative fluid pump comprising a rotor having rotor blades for compressing fluid on a fluid flow path extending between a pump inlet and a pump outlet, the stator comprising a plurality of concentric channels which comprise pumping channel portions along which said rotor blades move for compressing fluid between respective inlets and respective outlets of the pumping channel portions and stripper channel portions for allowing said rotor blades to pass from said outlets to said inlets of the pumping channel portions, wherein pumping channel portions of two directly adjacent channels do not circumferentially overlap.
Other aspects of the invention are defined in the accompanying claims.
In order that the present invention may be well understood, an embodiment thereof, will now be described, with reference to the accompanying drawings, in which:
Figure 1 is a schematic representation of a regenerative fluid pump embodying the present invention;
Figure 2 is a cross-sectional view of a stator for the regenerative fluid pump shown schematically in Figure 1 taken along line II;
Figure 3 is a schematic view of a prior art regenerative fluid pump; and Figure 4 is a cross-sectional view of a stator for the regenerative fluid pump shown schematically in Figure 3 taken along line IV.
Referring to Figure 1 , a regenerative fluid pump 10 is shown which comprises four pumping stages although, more or less stages may be provided, as required. Pump 10 comprises a rotor having rotor blades for compressing fluid on a fluid flow path extending between a pump inlet 12 and a pump outlet 14, and a stator comprising a plurality of concentric channels 16 which comprise pumping channel portions 18 along which said rotor blades move for compressing said fluid between inlets and outlets of the pumping channel portions and stripper channel portions 20 which allows movement of said rotor blades from said outlets to said inlets of the pumping channel portions. Diversion channels 22 (indicated by arrows in Figure 1) divert fluid between the pumping channel portions in the same way as described above in relation to Figure 3.
The pumping channel portions 18 of any two directly adjacent concentric channels 16 do not circumferentially overlap so that the stripper channel portions 20 are directly adjacent the pumping channel portions 18, over the circumferential extent of the pumping channel portions. With this arrangement, radial cross-sections taken through the stator reveal that the stripper channel portions and the pumping channel portions alternate from the centre of the stator radially outwards. This does not apply to a cross-section taken at the diversion channels 22 where the channel portions do not alternate.
Operation of the regenerative fluid pump 10 is similar to that described with reference to Figure 3 above and therefore will not be described further in detail. Shown in Figure 2 is a cross-section of a stator 24 for the pump 10 shown schematically in Figure 1. Figure 2 shows stator 24 as viewed along line II. Stator 24 is provided with six concentric channels 16 (i.e. is suitable for a six stage pump) whereas only four pumping stages are shown in Figure 1.
In figure 2, stripper channel portions 20 alternate with pumping channel portions 18 along radial line II from centre C. The stripper channel portions are thinner than the pumping channel portions because the stripper channel portions are designed to closely match the shape of the rotor blades to reduce the amount of fluid which is able to seep along the stripper channel portions during use. The alternating characteristic of the pumping channel portions 18 and the stripper channel portions enables the overall width of the concentric channels 16 W to be reduced relative to the width W as in the prior art. Accordingly, stator 24 allows a regenerative fluid pump of smaller overall dimensions as compared with the prior art.
The concentric channels 16 comprise radially inner directly adjacent channels 16c, 16d and radial outer directly adjacent channels 16a, 16b, and the pumping channel portions 18a, 18b of the radially outer channel 16a, 16b are wider than the pumping channel portions 18c, 18d of the radially inner concentric channels 16c, 16d. This arrangement aids compression of fluid as it is directed radially inwardly. In a modification of pump 10, pumping channel portions 18a, 18b of the two directly adjacent radially outer channels 16a, 16b do not circumferentially overlap since these pumping channel portions are relatively wide, whereas pumping channel portions 18c, 18d of the two directly adjacent radially inner channels 16c, 16d circumferentially overlap since these pumping channel portions are relatively thin and there is little reduction overall width to be gained by angular alignment of pumping channel portions 18c, 18d with stripper channel portions 20c, 20d. It will also be appreciated that an arrangement in which the pumping channel portions of no more than two directly adjacent channels do not overlap will still contribute to a reduction in overall width of the pump. The arrangement shown in Figures 1 and 2 shows no appreciable loss in performance from the prior art even though the length of the pumping channel portions 18 has been reduced and the length of the stripper channel portions 20 has been increased. This is because the relatively greater compression takes place in the latter part of the respective pumping channel portions closest to the outlet of the respective pumping channel portions. Reference is made to the Applicant's co-pending application (GB0215708.9) in which the effect of reducing the length of the pumping channel portion length is discussed in more detail.
Figure 1 shows an arrangement in which the stripper channel portions 20 and pumping channel portions 18 extend for about 180° of the circumference of the respective concentric channels 16. The present invention is not limited to such an arrangement. The pumping channel portions 18 may extend more or less than 180° for each concentric channel 16 provided that the stripper channel portions of each concentric channel are adjacent the pumping channel portions of an adjacent concentric channel 16, allowing the above described reduction in the size of the stator 24.
It will also be appreciated that stator size reduction may be achieved provided that the pumping channel portion and the stripper channel portion of at least one of said concentric channels are adjacent the stripper channel portion and the pumping channel portion, respectively, of an adjacent said concentric channel over the circumference of said at least one and said adjacent channels. In other words, the alternating relationship of the pumping channel portions 18 and the stripper channel portions 20 need not be present over the entire radial extent of the stator.
Figure 1 shows a radial regenerative fluid pump which allows the radial width of the stator to be reduced. However, the present invention is also relative to an axial regenerative fluid pump, although, with an axial pump, the arrangement would allow the axial length of the pump to be reduced.

Claims

1. A regenerative fluid pump comprising a rotor having rotor blades, and a stator comprising a plurality of concentric channels which comprise pumping channel portions along which said rotor blades move for compressing fluid between respective inlets and respective outlets of the pumping channel portions and stripper channel portions for allowing said rotor blades to pass from said outlets to said inlets of the pumping channel portions, wherein pumping channel portions of two directly adjacent channels do not circumferentially overlap.
2. A regenerative fluid pump as claimed in claim 1 , wherein the pumping channel portions of any two directly adjacent channels do not circumferentially overlap.
3. A regenerative fluid pump as claimed in claim 1 or 2, wherein respective said pumping channel portions and respective said stripper channel portions extend in the circumferential direction for an angle of about 180°.
4. A regenerative fluid pump as claimed in claim 1 , 2 or 3, wherein diversion channels divert fluid from respective outlets of said pumping channel portions to respective inlets of radially inward pumping channel portions, and wherein any radial line extending from a centre of the concentric channels that does not pass through a said diversion channel passes through alternately said pumping channel portions and said stripper channel portions.
5. A regenerative fluid pump as claimed in claim 1 , wherein the concentric channels comprise radially inner directly adjacent channels and radial outer directly adjacent channels, and the pumping channel portions of two directly adjacent radially outer channels do not overlap.
6. A stator for a regenerative fluid pump comprising a rotor having rotor blades for compressing fluid on a fluid flow path extending between a pump inlet and a pump outlet, the stator comprising a plurality of concentric channels which comprise pumping channel portions along which said rotor blades move for compressing fluid between respective inlets and respective outlets of the pumping channel portions and stripper channel portions for allowing said rotor blades to pass from said outlets to said inlets of the pumping channel portions, wherein pumping channel portions of two directly adjacent channels do not circumferentially overlap.
7. A regenerative fluid pump substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.
8. A stator for a regenerative fluid pump substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.
PCT/GB2003/002904 2002-07-05 2003-07-04 A regenerative fluid pump and stator for the same WO2004005721A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003244835A AU2003244835A1 (en) 2002-07-05 2003-07-04 A regenerative fluid pump and stator for the same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0215706.3 2002-07-05
GB0215706A GB0215706D0 (en) 2002-07-05 2002-07-05 A regenerative fluid pump and stator for the same

Publications (1)

Publication Number Publication Date
WO2004005721A1 true WO2004005721A1 (en) 2004-01-15

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PCT/GB2003/002904 WO2004005721A1 (en) 2002-07-05 2003-07-04 A regenerative fluid pump and stator for the same

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AU (1) AU2003244835A1 (en)
GB (1) GB0215706D0 (en)
WO (1) WO2004005721A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917431A (en) * 1973-09-18 1975-11-04 Dresser Ind Multi-stage regenerative fluid pump
GB2253246A (en) * 1990-12-15 1992-09-02 Dowty Defence & Air Syst Regenerative pump
US5536148A (en) * 1993-09-17 1996-07-16 Hitachi, Ltd. Turbo vacuum pump
EP0805275A2 (en) * 1996-05-03 1997-11-05 The BOC Group plc Vacuum pumps
US6179579B1 (en) * 1998-03-18 2001-01-30 Robert Bosch Gmbh Multi-stage side-channel fuel pump for a motor vehicle

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917431A (en) * 1973-09-18 1975-11-04 Dresser Ind Multi-stage regenerative fluid pump
GB2253246A (en) * 1990-12-15 1992-09-02 Dowty Defence & Air Syst Regenerative pump
US5536148A (en) * 1993-09-17 1996-07-16 Hitachi, Ltd. Turbo vacuum pump
EP0805275A2 (en) * 1996-05-03 1997-11-05 The BOC Group plc Vacuum pumps
US6179579B1 (en) * 1998-03-18 2001-01-30 Robert Bosch Gmbh Multi-stage side-channel fuel pump for a motor vehicle

Also Published As

Publication number Publication date
AU2003244835A1 (en) 2004-01-23
GB0215706D0 (en) 2002-08-14

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