U.S. patent application number 10/619669 was filed with the patent office on 2004-01-22 for impeller for fuel pump.
Invention is credited to Aslam, Mohammed, Jeswani, Partab.
Application Number | 20040013513 10/619669 |
Document ID | / |
Family ID | 30448518 |
Filed Date | 2004-01-22 |
United States Patent
Application |
20040013513 |
Kind Code |
A1 |
Jeswani, Partab ; et
al. |
January 22, 2004 |
Impeller for fuel pump
Abstract
An impeller for a fuel pump includes a hub portion adapted for
attachment to a rotatable shaft. The impeller also includes a
plurality of blades extending outwardly from the hub portion and
disposed circumferentially thereabout. The impeller further
includes a peripheral ring portion extending outwardly from the
blades to shroud the blades. The blades are non-radial relative to
a center axis of the hub portion.
Inventors: |
Jeswani, Partab; (Grand
Blanc, MI) ; Aslam, Mohammed; (Flint, MI) |
Correspondence
Address: |
DELPHI TECHNOLOGIES, INC.
Legal Staff
P.O. Box 5052
Mail Code: 480-410-202
Troy
MI
48007-5052
US
|
Family ID: |
30448518 |
Appl. No.: |
10/619669 |
Filed: |
July 15, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60396771 |
Jul 18, 2002 |
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Current U.S.
Class: |
415/55.1 |
Current CPC
Class: |
F04D 29/188
20130101 |
Class at
Publication: |
415/55.1 |
International
Class: |
F04D 001/04 |
Claims
1. An impeller for a fuel pump comprising: a hub portion adapted
for attachment to a rotatable shaft; a plurality of blades
extending outwardly from said hub portion and disposed
circumferentially thereabout; a peripheral ring portion extending
outwardly from said blades to shroud said blades; and said blades
being non-radial relative to a center axis of said hub portion.
2. An impeller as set forth in claim 1 wherein said blades have an
inner diameter and an outer diameter and extend outwardly at an
angle at least greater or less than zero therebetween.
3. An impeller as set forth in claim 1 wherein said blades are back
slanted from said inner diameter to said outer diameter.
4. An impeller as set forth in claim 1 wherein said blades are
angled from said inner diameter to said outer diameter from
approximately -5 degrees to approximately 20 degrees.
5. An impeller as set forth in claim 1 wherein said blades are
angled from said inner diameter to said outer diameter
approximately 5 degrees.
6. An impeller as set forth in claim 1 wherein said each of the
blades have a trailing edge that does not extend through the center
axis.
7. An impeller as set forth in claim 1 wherein said blades are
generally V shaped.
8. A fuel pump comprising: a pump section having a flow channel and
a rotatable impeller cooperating with said flow channel to pump
fuel therethrough; a motor section disposed adjacent said pump
section and having a motor to rotate said impeller; an outlet
section disposed adjacent said motor section to allow pumped fuel
to exit said fuel pump; and said impeller including a plurality of
blades that are non-radial relative to a center axis thereof.
9. A fuel pump as set forth in claim 8 wherein said impeller
comprises a hub portion attachment to a rotatable shaft of said
motor, a plurality of blades extending outwardly from said hub
portion and disposed circumferentially thereabout, and a peripheral
ring portion extending outwardly from said blades to shroud said
blades, wherein each of said blades has a trailing edge.
10. An impeller as set forth in claim 8 wherein said blades have an
inner diameter and an outer diameter and extend therebetween at an
angle at least greater or less than zero therebetween.
11. An impeller as set forth in claim 8 wherein said blades are
back slanted from said inner diameter to said outer diameter.
12. An impeller as set forth in claim 8 wherein said blades are
angled from said inner diameter to said outer diameter from
approximately -5 degrees to approximately 20 degrees.
13. An impeller as set forth in claim 8 wherein said blades are
angled from said inner diameter to said outer diameter
approximately 5 degrees.
14. An impeller as set forth in claim 8 wherein said trailing edge
of each of said blades does not extend through the center axis.
15. A fuel pump as set forth in claim 8 wherein said blades are
generally V shaped.
16. A fuel pump as set forth in claim 8 wherein said pump section
includes an inlet plate disposed axially adjacent one side of said
impeller.
17. A fuel pump as set forth in claim 16 wherein said pump section
includes an outlet plate disposed axially adjacent an opposed side
of said impeller.
18. A fuel pump as set forth in claim 8 including a spacer ring
spaced radially from said impeller.
19. A fuel pump as set forth in claim 18 including a housing
enclosing said pump section and said spacer ring being fixed to
said housing and stationary relative to said impeller.
20. A fuel pump comprising: a housing; a pump section disposed in
said housing having a flow channel and a rotatable impeller
cooperating with said flow channel to pump fuel therethrough, said
impeller having a hub portion, a plurality of blades extending
outwardly from and disposed circumferentially about said hub
portion and a peripheral ring portion extending outwardly from said
blades; a motor section disposed in said housing adjacent said pump
section and having a motor to rotate said impeller; an outlet
section disposed in said housing adjacent said motor section to
allow pumped fuel to exit said fuel pump; and said impeller
including a plurality of blades that are generally V shaped and are
non-radial relative to a center axis thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The present invention claims the priority date of copending
U.S. Provisional Patent Application Serial No. 60/396,771, filed
Jul. 18, 2002.
TECHNICAL FIELD
[0002] The present invention relates generally to fuel pumps for
vehicles and, more particularly, to an impeller for a fuel
pump.
BACKGROUND OF THE INVENTION
[0003] It is known to provide a fuel tank in a vehicle to hold fuel
to be used by an engine of the vehicle. It is also known to provide
a fuel pump to pump fuel from the fuel tank to the engine. One type
of fuel pump is known as a high-pressure turbine or regenerative
fuel pump. These pumps are used extensively in automotive
applications due to their ability to generate high heads at small
flow rates. These pumps are small and easy to manufacture, but they
have a fairly low efficiency due to the tortuous path the fluid
must follow as it moves from the inlet to the outlet.
[0004] Over the past few years, strong emphasis has been placed to
make these fuel pumps more efficient. It is estimated that for
every ampere of current drawn by these fuel pumps, the internal
combustion engine efficiency degrades by one percent (1%).
[0005] In general, the high-pressure turbine fuel pump typically
includes an impeller rotatable between an inlet plate, an outlet
plate, and a spacer. The impeller has a plurality of vanes or
blades positioned in the radial direction. If extended, these vanes
or blades will pass through the center of the impeller. The fuel
pump also includes peripheral channels machined in the inlet and
the outlet plates. The fuel pump further includes a motor having a
drive shaft to rotate the impeller.
[0006] In operation, as the impeller rotates, it imparts energy to
the fluid trapped between the blades. As the fluid is pushed along
a circular path, it is pushed in the tangential direction.
Centrifugal force then causes the fluid to leave the impeller and
enter the channels. The resulting motion of the fluid is that of a
spiral. This process continues until the fluid encounters a
blockage (called stripper) in the channels and it then exits
through the outlet.
[0007] As the fluid moves in and out of the impeller, it loses
energy due to entry and exit losses as well as friction. The
impeller must constantly supply energy to the fluid to overcome
these losses.
[0008] Therefore, it is desirable to provide an impeller for a fuel
pump that minimizes those losses as fluid particles enter and exit
the impeller from a channel in a pump section of the fuel pump. It
is also desirable to provide an impeller in a fuel pump for a fuel
tank in a vehicle that improves the mechanical efficiency of the
high-pressure pump section of the fuel pump. It is further
desirable to provide an impeller for a fuel pump that draws a
smaller amount of current. Therefore, there is a need in the art to
provide an impeller for a fuel pump that meets these desires.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is an impeller for a fuel
pump including a hub portion adapted for attachment to a rotatable
shaft. The impeller also includes a plurality of blades extending
outwardly from the hub portion and disposed circumferentially
thereabout. The impeller further includes a peripheral ring portion
extending outwardly from the blades to shroud the blades. The
blades are non-radial relative to a center axis of the hub
portion.
[0010] One advantage of the present invention is that a new
impeller for a fuel pump is provided. Another advantage of the
present invention is that the impeller has a plurality of blades
that are slanted or non-radial to improve the efficiency of the
fuel pump. Yet another advantage of the present invention is that
the impeller has non-radial blades to reduce friction losses as
fluid particles enter and exit the impeller from a channel in a
pump section of the fuel pump. Still another advantage of the
present invention is that the impeller has non-radial blades that
reduce the amount of current drawn by the fuel pump, thereby
increasing the efficiency of the fuel pump. Still another advantage
of the present invention is that the impeller minimizes friction
losses and improves the overall mechanical efficiency of the pump
section of the fuel pump. A further advantage of the present
invention is that the impeller has slanted blades, thereby
achieving higher flow for the fuel pump versus standard radial
blades.
[0011] Other features and advantages of the present invention will
be readily appreciated, as the same becomes better understood,
after reading the subsequent description taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a fragmentary elevational view of a fuel pump,
according to the present invention.
[0013] FIG. 2 is a plan view of an impeller, according to the
present invention, of the fuel pump of FIG. 1.
[0014] FIG. 3 is an enlarged plan view of a portion of the impeller
in circle 3 of FIG. 2.
[0015] FIG. 4 is a sectional view taken along line 4-4 of FIG.
3.
[0016] FIG. 5 is a perspective view of an exploded portion of the
impeller of FIG. 2.
[0017] FIG. 6 is a graph of hydraulic efficiency of the fuel pump
of FIG. 1 at various slant angles.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to the drawings and in particular FIGS. 1 and 2,
one embodiment of a fuel pump 12, according to the present
invention, is shown. The fuel pump 12 includes a pump section 14 at
one axial end, a motor section 16 adjacent the pump section 14, and
an outlet section 18 adjacent the motor section 16 at the other
axial end. As known in the art, fuel enters the pump section 14,
which is rotated by the motor section 16, and is pumped past the
motor section 16 to the outlet section 18. The outlet section 18
has an outlet member 20 extending axially with a passageway 22
extending axially therethrough. The outlet member 20 also has a
plurality of projections or barbs 24 extending radially outwardly
for attachment to a conduit (not shown). The outlet member 20 also
includes a check valve 26 disposed in the passageway 22. It should
be appreciated that the fuel flowing to the outlet section 18 flows
into the outlet member 20 and through the passageway 22 and check
valve 26 when open to the conduit. It should also be appreciated
that, except for the pump section 14, the fuel pump 12 is
conventional and known in the art.
[0019] The pump section 14 includes an impeller 28, according to
the present invention, mounted to a rotatable shaft 29 of a motor
30 of the motor section 16 for rotation therewith. The impeller 28
is generally planar and circular in shape. The impeller 28 has a
hub portion 31 attached to the shaft 29 by suitable means (not
shown). The impeller 28 also has a plurality of blade tips 32
extending radially from a hub diameter 33 of the hub portion 31 and
disposed circumferentially thereabout. The impeller 28 has a
peripheral ring portion 34 extending radially from the blade tips
32 to shroud the blade tips 32.
[0020] The pump section 14 also includes an inlet plate 35 disposed
axially on one side of the impeller 28 and an outlet plate 36
disposed axially on the other side of the impeller 28. The inlet
plate 35 and outlet plate 36 are generally planar and circular in
shape. The inlet plate 35 and outlet plate 36 are enclosed by a
housing 38 and fixed thereto. The inlet plate 35 and outlet plate
36 have an inlet or first recess 40 and an outlet or second recess
42, respectively, located axially opposite the blade tips 32
adjacent to the peripheral ring portion 34 to form a flow channel
43 for a function to be described. The recesses 40 and 42 are
generally annular and allow fuel to flow therethrough from an inlet
port (not shown) to an outlet port 44 of the pump section 14. The
peripheral ring portion 34 of the impeller 28 forms an outside
diameter (OD) sealing surface 46 on both axial sides thereof with
the inlet plate 35 and outlet plate 36. It should be appreciated
that the impeller 28 rotates relative to the inlet plate 35 and
outlet plate 36 and the inlet plate 35 and outlet plate 36 are
stationary relative to the impeller 28.
[0021] The pump section 14 also includes a spacer ring 48 disposed
axially between the inlet plate 35 and outlet plate 36 and spaced
radially from the impeller 28 to form a gap 50 therebetween. The
spacer ring 48 is fixed to the housing 38 and is stationary
relative to the impeller 28. The spacer ring 48 is generally planar
and circular in shape.
[0022] Referring to FIGS. 2 through 5, the impeller 28 has a
plurality of vanes or blades 52. Each of the blades 52 has an inner
diameter, which corresponds to the hub diameter 33, and an outer
diameter 54 and extending between the inner diameter and the outer
diameter 54. The blades 52 are generally "V" shaped. The blades 52
each have a trailing edge 56.
[0023] The blades 52 are non-radial. The blades 52 are slanted or
angled a predetermined amount (.theta.), such as approximately -5.0
to approximately 20 degrees, more preferably 5.0 degrees from a
radial line or axis 58 extending through a center axis 60 of the
impeller 28. In the embodiment illustrated, the optimum back slant
angle at which the efficiency is the highest is approximately five
degrees (5.degree.) relative to the radial axis 58 when a line 59
is projected from the trailing edge 56 of the blade 52. The blades
52 are slanted or non-radial, when extended, and will not pass
through the center axis 60 of the impeller 28. The blades 52 each
have a point of rotation 62 at the hub diameter 33 through which
the radial axis 58 extends and the trailing edge 56 of the blades
52 is slanted by the predetermined amount (.theta.) by the line 59
projected from the trailing edge 56 and extending through the point
of rotation 62. It should be appreciated that a plurality of blade
cavities 64 are disposed between the blades 56. It should also be
appreciated that fluid flows into the inlet recess 40 and through
the blade cavities 64 and out the outlet recess 42. It should
further be appreciated that, when the blades 52 are back slanted,
as illustrated in FIGS. 2 through 5, entrance and exit losses are
reduced and the fuel pump 10 becomes more efficient.
[0024] In operation of the fuel pump 12, the motor 30 rotates the
shaft 29, which in turn, rotates the impeller 28 as indicated by
the arrow. The fluid velocity created at the rotating surface of
the outside diameter or surface of the peripheral ring portion 33
of the impeller 28 coupled with the viscous force gradient within
the fluid cause the fluid such as fuel to flow. The fuel enters
from the inlet port. As the impeller 28 rotates, it imparts energy
to the fluid trapped between the blades 52. As the fluid is pushed
along a circular path, it is pushed in the tangential direction.
Centrifugal force then causes the fluid to leave the impeller 28
and enter the channels 43. The resulting motion of the fluid is
that of a spiral. This process continues until the fluid encounters
a blockage (called stripper) in the channels 43 and it then exits
through the outlet port 44.
[0025] Without slant on the blades 52, the fluid recirculates
between the impeller 28 and the channels 43 and turbulence at the
tip may occur as the flow exits from the impeller 28, resulting in
significant exit losses there. For that condition, the motor 30
must supply enough torque to the impeller 28 to overcome viscous
force and the inertia of the fluid while the blades 52 experience
pressure forces, which oppose the motion of the impeller 28.
[0026] In the present invention, the back slant on the blades 52
reduces these pressure forces and exit losses, thus making the
transfer of energy more efficient. The net result is more flow and
higher efficiency of the fuel pump 12. FIG. 4 shows the hydraulic
efficiency of the fuel pump 12 at various slant angles of the
blades 52. It should be appreciated that there is an optimum angle
of slant on the blades 52 at which the efficiency is the
highest.
[0027] The present invention has been described in an illustrative
manner. It is to be understood that the terminology, which has been
used, is intended to be in the nature of words of description
rather than of limitation.
[0028] Many modifications and variations of the present invention
are possible in light of the above teachings. Therefore, within the
scope of the appended claims, the present invention may be
practiced other than as specifically described.
* * * * *