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Fluid machine

Foreign code F120006093
File No. S2008-0293
Posted date Jan 6, 2012
Country United States of America
Application number 73560009
Gazette No. 20100322771
Gazette No. 8469654
Date of filing Jan 14, 2009
Gazette Date Dec 23, 2010
Gazette Date Jun 25, 2013
International application number JP2009050391
International publication number WO2009096226
Date of international filing Jan 14, 2009
Date of international publication Aug 6, 2009
Priority data
  • P2008-020236 (Jan 31, 2008) JP
  • 2009WO-JP50391 (Jan 14, 2009) WO
Title Fluid machine
Abstract (US8469654)
A rotary-type fluid machine which enables practical and effective operation in an extremely low specific speed range.
The rotary-type fluid machine (1, 1') has an impeller (10, 10') integrally connected to a rotating drive shaft (2).
The impeller is accommodated in a casing (3).
Fluid (a) of a suction fluid passage (4) to be pumped flows into a center part (11) of the impeller.
The fluid (b) is discharged from a peripheral portion (12) of the impeller by the effect of the centrifugal force of the rotating impeller, so that the fluid is delivered through a delivery fluid passage (5) outside of the casing.
Many grooves (15) extending toward a peripheral edge of the impeller from the center part of the impeller are formed on the impeller.
The groove opens on an outer circumferential surface (18) of the impeller, and causes strong recirculation vortices (R) to be formed in the vicinity of the peripheral edge of the impeller when the impeller rotates.
Scope of claims [claim1]
1. A rotary-type fluid machine having an impeller integrally connected to a rotating drive shaft; a casing for accommodating the impeller; and an intake port for fluid to be fed under pressure, which is provided so as to face a radially center portion of the impeller; the fluid machine comprising: many grooves extending radially outward from the radially center portion of the impeller, which are formed at angular intervals in a side surface of the impeller positioned on its side facing the intake port and opposed against a stationary wall surface of the casing, the angular interval being equal to or less than an angle of 10 degrees,
wherein the grooves open toward the stationary wall surface, extend toward an outer circumferential edge of the impeller from a region radially inward of the intake port and open on an outer circumferential surface of the impeller;
wherein a gap between the side surface of the impeller and a side wall surface of the casing has a dimension (q) equal to or greater than 0.4 mm or an impeller diameter (d2) * 0.002; and
wherein each of the grooves has a depth (h) equal to or greater than 0.4 mm or the impeller diameter (d2) * 0.002, and the grooves generate radially outward flows of said fluid in the respective grooves and recirculation vortices of the fluid increasing a fluid head of the fluid machine near a peripheral edge of the impeller when the impeller rotates.
[claim2]
19. A rotary-type fluid machine having an impeller integrally connected to a rotating drive shaft; a casing for accommodating the impeller; and an intake port for fluid to be fed under pressure, which is provided so as to face a radially center portion of the impeller; the fluid machine comprising: many grooves for generating recirculation vortices of said fluid near an outer edge of the impeller during rotation of the impeller, which grooves are formed in a side surface of the impeller positioned on its side facing the intake port and opposing against a stationary wall surface of the casing so that the vortices increase a fluid head of the fluid machine by raising a fluid pressure throughout a circumferential annular fluid passage outside of said impeller
wherein the grooves open toward the stationary wall surface, extend at angular intervals toward an outer circumferential edge of the impeller from a region radially inward of the intake port and opening on an outer circumferential surface of the impeller;
wherein the grooves have a depth (h) equal to or less than 0.6 mm or the impeller diameter (d2) * 0.03;
wherein the casing is a circular casing, which has a front side wall surface, a rear side wall surface and an annular inner circumferential wall surface, and which defines a circular casing inside region centering around a rotational axis of the impeller; and
wherein the recirculation vortices (R) are formed by radially outward flows (F) generated inside the grooves, radially inward flows (E) generated near the side wall surface of the casing, and recirculation flows (G) splitting from the radially inward flows (E) and recirculating into the grooves.
[claim3]
2. The machine as defined in claim 1, wherein said groove extends radially outward from the center portion of the impeller in a linear form, or extend outward therefrom in a curved form.
[claim4]
3. The machine as defined in claim 1, wherein said grooves converge in the center portion of the impeller so that an annular or circular depression or concave part is formed in the center portion.
[claim5]
4. The machine as defined in claim 3, wherein a diameter (d1) of the depression or concave part is larger than a diameter (d0) of the intake port, and the intake port is entirely encompassed by an external outline of the depression or concave part.
[claim6]
5. The machine as defined in one of claim 1, wherein the dimension (q) of said gap is set to be equal to or greater than 3.0 mm, or equal to or greater than the impeller diameter (d2) * 0.015.
[claim7]
6. The machine as defined in claim 1, wherein many grooves extending radially outward from the radially center portion of the impeller are further formed in a side surface of the impeller opposite to its side facing the intake port.
[claim8]
7. The machine as defined in claim 6, wherein communicating means for causing the gaps on both sides of the impeller to be in fluid communication with each other is provided in the radially center portion of the impeller.
[claim9]
8. The machine as defined in claim 1, wherein a depth (h) of the groove is set to be equal to or less than 6.0 mm or the impeller diameter (d2) * 0.03, and a width (w) of the groove is set to be equal to or less than 40 mm or the impeller diameter (d2) * 0.20.
[claim10]
9. The machine as defined in claim 1, wherein a thickness (T) of the center portion of the impeller is set to be a dimension larger than a thickness (T') of a peripheral portion of the impeller.
[claim11]
10. The machine as defined in claim 1, wherein the casing is a circular casing, which has a front side wall surface, a rear side wall surface and an annular inner circumferential wall surface, and which defines a circular casing inside region centering around a rotational axis of the impeller; a fluid suction passage for a fluid to be pumped is connected with the intake port of the fluid; and
a fluid delivery passage for discharging the fluid from the casing to its outside under pressure of a fluid passage in the casing is connected to said annular inner circumferential wall surface.
[claim12]
11. The machine as defined in claim 1, wherein the recirculation vortices (R) are formed by radially outward flows (F) formed inside the grooves, radially inward flows (E) formed near the side wall surface of the casing, and recirculation flows (G) splitting from the radially inward flows (E) and recirculating into the grooves.
[claim13]
12. The machine as defined in claim 11, wherein the radially outward flows (F) turn radially inward between an outer circumferential edge of the impeller and an annular inner circumferential wall surface (33) of the casing, and flow backward in the vicinity of the stationary wall surface as the radially inward flows (C, E).
[claim14]
13. The fluid machine as defined in claim 1, wherein said grooves are arranged uniformly at regular intervals (k) in the entire side surface of the impeller.
[claim15]
14. The fluid machine as defined in claim 1, wherein the fluid machine is a centrifugal pump which operates in an extremely low specific speed range equal to or less than 70.
[claim16]
15. A rotary-type fluid machine having an impeller integrally connected to a rotating drive shaft; a casing for accommodating the impeller; and an intake port for fluid to be fed under pressure, which is provided so as to face a radially center portion of the impeller; the fluid machine comprising: many grooves for generating recirculation vortices of said fluid increasing a fluid head of the fluid machine near an outer edge of the impeller during rotation of the impeller, which are formed in both side surfaces of the impeller opposing against stationary wall surfaces of the casing,
wherein the grooves in each of the surfaces of the impeller open toward stationary toward the stationary wall surface, extend at angular intervals toward an outer circumferential edge of the impeller from a region radially inward of the intake port and open on an outer circumferential surface of the impeller, the angular interval being equal to or less than an angle of 10 degrees,
whereby radially outward flows of said fluid are generated in the respective grooves when the impeller rotates.
[claim17]
16. The machine as defined in claim 15, wherein fluid communication holes extend through the radially center portion of the impeller, and each of the holes causes gaps on both sides of the impeller to be in fluid communication with each other, each of the gaps being formed between each of the surfaces of the impeller and each of side wall surfaces of the casing.
[claim18]
17. The machine as defined in claim 15, wherein said grooves converge in the radially center portion of the impeller so that an annular or circular depression or concave part is formed in the center portion, and said holes are located in the depression or concave part.
[claim19]
18. The machine as defined in claim 15, wherein the casing is a circular casing, which has a front side wall surface, a rear side wall surface and an annular inner circumferential wall surface, and which defines a circular casing inside region centering around a rotational axis of the impeller; a fluid suction passage for a fluid to be pumped is connected with the intake port; and
a fluid delivery passage for discharging the fluid from the casing to its outside under pressure of a fluid passage in the casing is connected to said annular inner circumferential wall surface.
[claim20]
20. The machine as defined in claim 19, wherein the radially outward flows (F) turn radially inward between the outer circumferential edge of the impeller and the annular inner circumferential wall surface (33) of the casing, and flow backward in the vicinity of said side wall surface of the casing as the radially inward flows (C, E).
  • Inventor, and Inventor/Applicant
  • KUROKAWA JUNICHI
  • KAGAWA SHUUSAKU
  • YOKOHAMA NATIONAL UNIVERISTY
IPC(International Patent Classification)
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