U.S. patent application number 09/839279 was filed with the patent office on 2002-01-10 for feed pump.
This patent application is currently assigned to Mannesmann VDO AG. Invention is credited to Marx, Peter.
Application Number | 20020004000 09/839279 |
Document ID | / |
Family ID | 7639660 |
Filed Date | 2002-01-10 |
United States Patent
Application |
20020004000 |
Kind Code |
A1 |
Marx, Peter |
January 10, 2002 |
Feed pump
Abstract
A feed pump includes two feed chambers one surrounding the other
and arranged at different axial levels from an electric motor
driving the feed pump. A radially inner feed chamber of the two
feed chambers is arranged for filling a baffle of a fuel tank of a
motor vehicle. The radially outer feed chamber is arranged for
suctioning in fuel from the baffle. The feed pump is of
particularly compact design and the radially inner feed chamber is
arranged at a low level in the baffle.
Inventors: |
Marx, Peter; (Wasbuttel,
DE) |
Correspondence
Address: |
Thomas C. Pontani, Esq.
Cohen, Pontani, Lieberman & Pavane
551 Fifth Avenue, Suite 1210
New York
NY
10176
US
|
Assignee: |
Mannesmann VDO AG
|
Family ID: |
7639660 |
Appl. No.: |
09/839279 |
Filed: |
April 20, 2001 |
Current U.S.
Class: |
415/55.1 |
Current CPC
Class: |
F04D 5/005 20130101 |
Class at
Publication: |
415/55.1 |
International
Class: |
F04D 001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 20, 2000 |
DE |
100 19 911.9 |
Claims
I claim:
1. A feed pump for installation in a baffle of a fuel tank,
comprising: a casing comprising part-annular channels, each
part-annular channel extending from an inlet channel to an outlet
channel; an impeller rotatably arranged for rotating in said casing
about an axis of rotation, said impeller having at least two rings
of guide blades concentrically arranged thereon and comprising a
radially inner ring of guide blades and a radially outer ring of
guide blades, each of said at least two rings of guide blades being
arranged opposite one of said part-annular channels, said impeller
further comprising and end face having a plurality of levels in the
axial direction relative to said axis of rotation, wherein said
radially inner ring of guide blades and said radially outer ring of
guide blades are arranged on two different ones of said plural
levels.
2. The feed pump of claim 1, wherein said impeller comprises a
continuous collar for separating said two different ones of said
plural levels and said pump casing has a step corresponding to said
collar.
3. The feed pump of claim 2, wherein said collar is
cylindrical.
4. The feed pump of claim 1, wherein said part-annular channels
comprise a radially inner part-annular channel and a radially outer
part-annular channel and said casing further comprises a web
arranged between the outlet channel and the inlet channel of said
radially outer part-annular channel, wherein one of said inlet
channel and said outlet channel of said radially inner part-annular
channel is lead radially outward via said web.
5. The feed pump of claim 4, further comprising an electric motor
driving said impeller, wherein said radially inner ring of guide
blades is arranged on a first level of said plural levels and said
radially outer ring of guide blades is arranged on a second level
of said plural levels, said first level being arranged at a greater
distance from said electric motor than said second level.
6. The feed pump of claim 5, wherein a thickness of said impeller
is greater in a region of said radially inner ring of guide blades
than in a region of said radially outer ring of guide blades.
7. The feed pump of claim 4, wherein said blade chambers comprise a
semicircular cross-section having a diameter and said diameter of
said blade chambers of said radially inner ring of guide blades is
approximately double said diameter of said blade chambers of said
radially outer ring of guide blades.
8. The feed pump of claim 4, wherein two of said at least two rings
of guide blades are arranged in a radially outer region of said
impeller and located on opposing sides of said impeller, said blade
chambers of said two of said at least to rings of guide blades
being connected to one another.
9. The feed pump of claim 1, further comprising an electric motor
driving said impeller, wherein said radially inner ring of guide
blades is arranged on a first level of said plural levels and said
radially outer ring of guide blades is arranged on a second level
of said plural levels, said first level being arranged at a greater
distance from said electric motor than said second level.
10. The feed pump of claim 9, wherein a thickness of said impeller
is greater in a region of said radially inner ring of guide blades
than in a region of said radially outer ring of guide blades.
11. The feed pump of claim 1, wherein said blade chambers comprise
a semicircular cross-section having a diameter and said diameter of
said blade chambers of said radially inner ring of guide blades is
approximately double said diameter of said blade chambers of said
radially outer ring of guide blades.
12. The feed pump of claim 1, wherein two of said at least two
rings of guide blades are arranged in a radially outer region of
said impeller and located on opposing sides of said impeller, said
blade chambers of said two of said at least two rings of guide
blades being connected to one another.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a feed pump for arrangement in a
baffle of a motor vehicle fuel tank, the feed pump having a driven
impeller rotatably arranged in a pump casing with a plurality of
rings or guide blades delimiting blade chambers, the rings
concentrically surrounding one another, and part-annular channels
arranged in the pump casing opposite the rings of blade chambers
and extending from an inlet channel to an outlet channel.
[0003] 2. Description of the Related Art
[0004] Feed pumps produced in the form of peripheral or
side-channel pumps are known from practice. The known feed pumps
may be of multistage design. For example, the feed pump may be
designed for feeding fuel from a fuel tank to a baffle and
simultaneously feeding fuel from the baffle to an internal
combustion engine of the motor vehicle. The impeller of the known
feed pump is typically fastened on a shaft of an electric motor.
Part annular chambers are arranged in a pump casing of the feed
pump corresponding to rings of guide blades which delimit blade
chambers in the impeller. Between the part-annular channels, the
pump casing is located with particularly slight clearance opposite
the impeller to form a sealing gap. This configuration allows a
plurality of pumping stages to be arranged on a single impeller.
Each of the pumping stages may be designed freely for the
respective application.
[0005] A problem of the known feed pump is that a pressure
difference between the part-annular channels one surrounding the
other leads to an overflow of the fed liquid and consequently to
high axial forces on the impeller. The overflow therefore reduces
the efficiency of the feed pump.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a feed
pump having part-annular channels one surrounding the other and
corresponding to rings of guide blades on an impeller such that
liquid to be fed is prevented from flowing between the part-annular
channels.
[0007] The object of the present invention is met by a feed pump
with an impeller having an end face with a plurality of levels in
the axial direction of the driven shaft on which the impeller is
mounted so that at least two rings of guide blades are arranged at
two different levels along the axial direction.
[0008] This configuration allows the sealing gap to be made
particularly long thereby providing particularly high resistance to
an overflow of the liquid to be fed. In comparison with the known
feed pump with a sealing gap having the same width, the feed pump
according to the present invention allows only a particularly small
amount of liquid to flow from one part-annular channel to another
part-annular channel. Axial forces acting on the impeller are
thereby kept particularly low. The feed pump according to the
present invention consequently has a particularly high efficiency.
Another advantage of this configuration is that the two levels
arranged in the impeller require that the impeller to be inserted
in the casing in the correct position. This ensures that impeller
is rotated in the intended direction of rotation by the shaft of
the electric motor.
[0009] According to an embodiment of the present invention, the
sealing gap may be kept particularly small if an axial play of the
impeller is provided. Furthermore, the impeller may have a
continuous collar for separating the different levels and the pump
casing may have a step corresponding to the collar.
[0010] According to another embodiment of the present invention,
the impeller and the pump casing may be manufactured particularly
cost-effectively when the collar is designed cylindrically.
[0011] The feed pump requires a particularly small axial
construction space when the inlet channel or the outlet channel of
the radially inner part-annular channel is led radially outward
through a web in the pump casing arranged between the outlet
channel and the inlet channel of the radially outer part-annular
channel.
[0012] A radially inner ring of guide blades is arranged on a first
level and a radially outer ring of guide blades is arranged on a
second level, wherein a plane of the first level at a greater
distance from an electric motor driving the impeller than the plane
of the second level. This configuration contributes facilitates
further reducing the axial dimensions of the feed pump. When the
feed pump is mounted with the electric motor, the radially outer
part-annular channel may be arranged at least partially radially
outside the electric motor. When the feed pump is mounted in the
baffle of a fuel tank, the radially inner ring of blade chambers
may thereby be arranged at a particularly low level thereby
avoiding a high suction head. A high suction head leads to the
formation of gas bubbles and therefore to a sharp drop in the
efficiency of the feed pump, particularly where the medium to be
fed is hot fuel. Locating the radially inner ring of blade chambers
at a particularly low level facilitates a high efficiency in the
feed pump according to the present invention.
[0013] According to another embodiment of the invention, the blade
chambers of the radially inner ring of guide blades have large
diameter and are designed for feeding as large a volume flow as
possible. In this embodiment, the impeller is thicker in the region
of the radially inner ring of guide blades than in the region of
the radially outer ring of guide blades.
[0014] A feed pump having high feed pressure provided when fuel is
intended to be fed to the internal combustion engine of a motor
vehicle and with as large a volume flow as possible to be fed into
the baffle may be designed with a particularly simple design when
the blade chambers of the radially inner ring of guide blades have
approximately double the diameter of the blade chambers of the
radially outer ring of guide blades.
[0015] According to another embodiment of the present invention, an
axial feed of the fuel through the feed pump may be achieved at
particularly low outlay in terms of construction when the impeller
has in the radially outer region of its end faces rings of guide
blades located opposite one another for forming blade chambers
therebetween, wherein the blade chambers on opposite sides of the
impeller are connected to one another.
[0016] Other objects and features of the present invention will
become apparent from the following detailed description considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for
purposes of illustration and not as a definition of the limits of
the invention, for which reference should be made to the appended
claims. It should be further understood that the drawings are not
necessarily drawn to scale and that, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In the drawing, wherein like reference characters denote
similar elements throughout the several views:
[0018] FIG. 1 is a longitudinal sectional view of a feed pump
according to the present invention mounted in the baffle of a motor
vehicle fuel tank; and
[0019] FIG. 2 is a top view of a lower casing part of a pump casing
of the feed pump from FIG. 1.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0020] FIG. 1 shows a bottom of a fuel tank 1 of a motor vehicle
with a baffle 2 supported relative to the bottom of the fuel tank
1. A feed pump 3 is arranged within the baffle 2. The feed pump 3
forms a structural unit with an electric motor 4. A connection
piece 5 of the feed pump 3 passes through the bottom of the baffle
2 and a filter 6 resting against the bottom of the fuel tank 1 is
attached to the connection piece 5. In the interests of simplicity,
the filter 6 is illustrated diagrammatically in FIG. 1. The feed
pump 3 has two inlet channels 7, 8, wherein inlet channel 7 is lead
through the connection piece 5 to the filter 6 and inlet channel 8
is arranged proximate the bottom of the baffle 2. The feed pump 3
also has two outlet channels 9, 10, wherein outlet channel 9 opens
into the baffle 2 and outlet channel 10 opens into a housing 11 of
the electric motor 4. An impeller 13 of the feed pump 3 is arranged
on a shaft 12 of the electric motor 4 such that the impeller 13 is
fixed with respect to rotation relative to the shaft 12. The
impeller 13 is located with a slight clearance opposite a
stationary pump casing 14 for forming a sealing gap between the
impeller 13 and the pump casing 14. The shaft 12 is mounted in the
pump casing 14 via a ball 15.
[0021] The pump casing 14 includes a lower casing part 17 and an
upper casing part 16. The lower casing part 17 has the two inlet
channels 7, 8. The impeller 13 has two end faces 34, 36 with two
levels 18, 19 arranged on the end face 34 of the impeller 13 and
spaced apart axially from one another along the axial direction of
the shaft 12. The levels 18, 19 are separated from one another by a
continuous collar 20.
[0022] The impeller 13 has a radially inner ring of guide blades
21. Two radially outer rings of guide blades 22 are arranged in a
radially outer region of the impeller 13 and located opposite one
another. The guide blades 21, 22 respectively delimit blade
chambers 23, 24 arranged in the impeller 13. The radially inner
ring of guide blades 21 is arranged on the level 18 which is
further away from the electric motor 4 than the level 19 on which
the radially outer rings of guide blades 22 are arranged. Those
blade chambers 24 of the radially outer rings of guide blades 22
which are located opposite one another are connected to one
another. The pump casing 14 includes part-annular channels 25, 26
respectively arranged in the region of the rings of guide blades
21, 22. The part-annular channels 25, 26 and the blade chambers 23,
24 respectively form feed chambers 27, 28 which extend from one of
the inlet channels 7, 8 as far as one of the outlet channels 9, 10.
When the impeller 13 rotates, the feed pump 3 feeds fuel out of the
fuel tank 1 through the radially inner feed chamber 27 into the
baffle 2 and through the radially outer feed chamber 28 out of the
baffle 2 through the electric motor 4 to an internal combustion
engine, not illustrated, of the motor vehicle.
[0023] The outlet channel 9 of the radially inner feed chamber 27
is led radially outward via a web 29. The continuous collar 20 is
located with slight clearance opposite a step 30 of the pump casing
14. This region therefore serves as a sealing gap which largely
prevents fuel from flowing over between feed chambers 27, 28 having
different pressures. To simplify the drawing, the inlet channels,
7, 8 and the outlet channels 9, 10 are arranged opposite one
another. The part-annular channels 25, 26 may, of course, also
extend over a larger angular range.
[0024] FIG. 2 shows a view of the lower casing part 17 of the pump
casing 14, as seen from the impeller 13 from FIG. 1. This drawings
shows that the part-annular channels 25, 26 extend over an angular
range of approximately 300.degree..
[0025] Thus, while there have shown and described and pointed out
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements which perform substantially the same
function in substantially the same way to achieve the same results
are within the scope of the invention. Moreover, it should be
recognized that structures and/or elements shown and/or described
in connection with any disclosed form or embodiment of the
invention may be incorporated in any other disclosed or described
or suggested form or embodiment as a general matter of design
choice. It is the intention, therefore, to be limited only as
indicated by the scope of the claims appended hereto.
* * * * *