U.S. patent application number 10/766455 was filed with the patent office on 2005-07-28 for automotive fuel pump improvement.
Invention is credited to Carter, Larry R., Morris, R. David.
Application Number | 20050163627 10/766455 |
Document ID | / |
Family ID | 34795674 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050163627 |
Kind Code |
A1 |
Morris, R. David ; et
al. |
July 28, 2005 |
Automotive fuel pump improvement
Abstract
A multi-stage turbine fuel pump (10) for automotive vehicles
includes an inlet section (12) through which low pressure fuel is
drawn into the pump, a first pump stage (14a) and a second pump
stage (14b), and an outlet section (16) through which high pressure
fuel is discharged from the pump. Components (13, 22a and 22b)
comprising a pump inlet and respective first and second pump stages
are aligned together by spring pins (32) inserted in open channels
(36, 38, 44a and 44b) extending through the components so to
improve fuel flow through the pump and prevent fuel leakage between
the stages. Each pin has a hollow, cylindrical shape with a
longitudinal slot (34) extending the length of the pin. The pins
are made of a spring material, and each pin is compressed when
inserted in place for the pin to thereafter press against a
sidewall of the channel in which it is inserted, the force exerted
by the pin on the channel sidewall maintaining alignment of the
components.
Inventors: |
Morris, R. David;
(Fairfield, IL) ; Carter, Larry R.; (Fairfield,
IL) |
Correspondence
Address: |
POLSTER, LIEDER, WOODRUFF & LUCCHESI
12412 POWERSCOURT DRIVE SUITE 200
ST. LOUIS
MO
63131-3615
US
|
Family ID: |
34795674 |
Appl. No.: |
10/766455 |
Filed: |
January 28, 2004 |
Current U.S.
Class: |
417/244 ;
417/423.14 |
Current CPC
Class: |
F04D 29/628 20130101;
F04D 5/006 20130101 |
Class at
Publication: |
417/244 ;
417/423.14 |
International
Class: |
F04B 003/00; F04B
005/00 |
Claims
Having thus described the invention, what is claimed and desired to
be secured by Letters Patent is:
1. In a multi-stage turbine fuel pump for automotive vehicles, the
pump having an inlet section through which low pressure fuel is
drawn into the pump, a first pump stage and a second pump stage,
and an outlet section through which high pressure fuel is
discharged from the pump, the improvement comprising alignment
means for assembling together and properly aligning components
comprising the respective first and second pump stages, the
alignment means maintaining alignment of the components during and
after pump assembly and dissipating forces which otherwise would be
concentrated about the alignment means which could cause failure of
the components.
2. The fuel pump improvement of claim 1 in which the inlet section
includes an end cap having an opening therein through which fuel is
drawn into the pump, the first pump stage includes including an
impeller and a port plate in which the impeller is installed, the
second stage the port plate and a casing in which a second impeller
is installed, and the alignment means includes means extending
between the end cap, port plate, and casing to align the inlet
section and pump stages.
3. The fuel pump improvement of claim 2 in which the alignment
means includes a spring pin extending between the end cap and the
casing for the second pump stage to align the components together,
and an open channel formed in each of the end cap and casing in
which the spring pin is received.
4. The fuel pump improvement of claim 3 further including a second
spring pin for aligning the components, and a second open channel
formed in each of the end cap, port plate, and casing in which the
second spring pin is received.
5. The fuel pump improvement of claim 4 in which the end cap has
first and second recesses formed therein for receiving one end of
each spring pin and the casing has first and second recesses formed
therein for receiving the other end of each spring pin.
6. The fuel pump improvement of claim 5 wherein-the port plate has
open sided, spaced channels formed therein through which each of
the spring pins extends.
7. The fuel pump improvement of claim 6 in which each spring pin
has a hollow, cylindrical shape with a longitudinal slot extending
the length of the pin.
8. The fuel pump improvement of claim 7 in which the recesses
formed in the end cap and casing and the channels formed in the
port plate through which the spring pins are inserted to align the
components all open into a sidewall of the respective component so
forces transmitted from a spring pin to the component are
dissipated through the component rather than concentrated about the
recess or channel, thereby to prevent cracking of the
component.
9. The fuel pump improvement of claim 8 in which the pins are made
of a spring material, the springs being compressed when the
inserted in the channels of the port plate with the pins thereafter
expanding against a sidewall of the channel with the force exerted
by the pin on the channel sidewall maintaining alignment of the
components.
10. The fuel pump improvement of claim 4 in which the two spring
pins and the open channels formed in the end cap, port plate, and
casing are arranged in a predetermined angular relationship with
each other for proper alignment of the fuel pump components during
pump assembly.
11. A multi-stage turbine fuel pump for automotive vehicles
comprising: an inlet section through which low pressure fuel is
drawn into the pump; a first pump stage and a second pump stage; an
outlet section through which high pressure fuel is discharged from
the pump; and, alignment means for aligning the components
comprising the respective first and second pump stages, the
alignment means maintaining alignment of the components during and
after the pump is assembled and dissipating forces which otherwise
would be concentrated about the alignment means which could cause
failure of the components.
12. The fuel pump of claim 11 in which the inlet section includes
an end cap having an opening therein through which fuel is drawn
into the pump, a first pump stage including an impeller and a port
plate in which the impeller is mounted, and a second pump stage
including a casing and an impeller mounted between the port plate
and casing, the alignment means including at least one spring pin
extending between the end cap, through the port plate, and into the
casing to properly align the inlet section and pump stages
together, and an open channel formed in the end cap, port plate,
and casing in which the spring pin is received.
13. The fuel pump of claim 12 including a pair of spring pins for
connecting the components together, the spring pins being installed
on opposite sides of the fuel pump, and an open channel formed in
the end cap, port plate, and casing in which each of the spring
pins is received.
14. The fuel pump of claim 13 in which the end cap has first and
second open sided pockets formed therein for supporting one end of
each spring pin and the casing has first and second open sided
pockets formed therein for supporting the other end of each spring
pin.
15. The fuel pump of claim 14 wherein the port plate for the first
pump stage, which is intermediate the end plate and port plate for
the second pump stage, has a pair of open sided channels formed
therein through which the spring pins extend.
16. The fuel pump of claim 15 in which each spring pin has a
hollow, cylindrical shape with a longitudinal slot extending the
length of the pin, the pins being made of a spring material, and
each pin being compressed when inserted in place for the pin to
thereafter press against a sidewall of the channel in which it is
inserted, the force exerted by the pin on the channel sidewall
maintaining alignment of the components.
17. An alignment means for use in a multistage turbine fuel pump
for aligning components comprising respective stages of the pump,
the alignment means including a spring pin made of a spring
material and the fuel pump components each having an open channel
formed therein with the spring pin, when installed in the channel,
exerting a force on the components to maintain them in
alignment.
18. The alignment means of claim 17 including a pair of
substantially identically formed spring pins, the fuel pump
components including respective open channels for each pin.
19. The alignment means of claim 18 each spring pin has a hollow,
cylindrical shape with a longitudinal slot extending the length of
the pin, each pin being compressed when inserted in a channel for
the pins to thereafter press against a sidewall of the channel in
which it is inserted, the force exerted by the pin on the channel
sidewall holding the components in alignment.
20. The alignment means of claim 19 in which the two spring pins
and the open channels formed in which the spring pins are received
are arranged in a preferred orientation to properly align the
components during pump assembly.
21. The alignment means of claims 19 in which the fuel pump is a
two stage fuel pump having an inlet end cap, a first stage port
plate and a second stage casing, the inlet end cap, port plate, and
casing each having open channels formed therein in which the
respective spring pins are received, thereby to dissipate forces
transferred from the spring pins to these components rather than
concentrating the forces thereabout and causing damage to the
components.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] This invention relates to electrical fuel pumps for use in
automobiles and other vehicles; and more particularly, to a slotted
spring pin and slot construction for aligning and holding
components of the pump stages together and which prevents cracking
of pump components in which the slots are formed so to prevent
failure of a pump.
[0004] Multi-stage fuel pumps for use in automotive vehicles are
known in the art. The pump typically is a two-stage pump having a
first and low pressure inlet stage followed by a second and high
pressure outlet stage. The two pump stages, together with the
electric motor driving the pump and the respective end caps in
which inlet and outlet ports are formed must be accurately aligned
during pump assembly in order for the pump to efficiently pump fuel
from a tank to the engine in which the fuel is combusted. One way
of achieving this alignment is to use screws which are inserted
through holes in the respective components with a threaded end of
the screw being threaded into a bore correspondingly threaded to
receive the screw. An alternative approach is use of a pin inserted
through bores in the pump components. The pins, which are enclosed
or encapsulated within the bores formed in the parts, are
compressed when the components are assembled together. Another
alternative approach is use of either one or two spring clips
applied to the outside perimeter of the pump components.
[0005] It has been that, over time, problems occur with each of
these installations. With threaded screws, vibrations and shocks to
which the pump is subjected will tend to loosen the screws. Even a
slight loosening of the screws will affect pump performance since
small gaps will appear between parts causing leakages which effect
pumping efficiency. With pins, the vibrations and shocks to which
the pins are subjected are transmitted to the portion of the parts
surrounding the pins, and will cause cracks to occur about the
bores in these components. This weakens these parts and can
ultimately lead to their failure. With the spring clips, alignment
of the components is inconsistent and can result in low fuel flow
through the pump and/or high amperage failures.
[0006] The present invention is directed to a spring pin and slot
construction by which proper alignment of pump components is
achieved and subsequent problems caused by shock and vibrations are
avoided.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention, briefly stated, is directed to a
multi-stage turbine fuel pump for automotive vehicles. The fuel
pump includes an inlet section through which low pressure fuel is
drawn into the pump, a first pump stage and a second pump stage,
and an outlet section through which high pressure fuel is
discharged from the pump. Components comprising the respective
first and second pump stages are aligned together by pins inserted
in channels extending through the components to properly orient the
parts. Each pin has a hollow, cylindrical shape with a longitudinal
slot extending the length of the pin. The pins are made of a spring
material, and each pin is compressed when the pump components are
assembled together. The channels in each of the parts through which
the pins are inserted comprise slots or pockets which open into the
outer surface of the part. This construction helps distribute
forces exerted by the pins against the sidewalls of the channels
when the pump is subjected to shocks and vibrations, so to prevent
the parts from cracking about the area where the channels are
formed, weakening the parts.
[0008] Other objects and features will be in part apparent and in
part pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] The objects of the invention are achieved as set forth in
the illustrative embodiments shown in the drawings which form a
part of the specification.
[0010] FIG. 1 is a perspective view of an automotive electric fuel
pump incorporating the improvement of the present invention;
[0011] FIGS. 2A and 2B are assembled views of the fuel pump
illustrating the an open channel construction for spring pins used
to align the parts;
[0012] FIGS. 3A and 3B are exploded views of the fuel pump with its
outer cover removed;
[0013] FIGS. 4A-4D are respective perspective, end and two side
views of a spring pin of the present invention for aligning
components of a two-stage turbine assembly portion of the fuel
pump;
[0014] FIG. 5 is a close-up view of an open channel, socket portion
of one component of the turbine assembly in which one end of a
spring pin is received;
[0015] FIG. 6 is a view similar to FIG. 5 with a spring pin
installed;
[0016] FIG. 7 is a perspective view of the turbine assembly with
spring pins installed for aligning the parts of the assembly;
and,
[0017] FIG. 8 is a plan view of a port plate illustrating the
channels formed therein for the spring pins.
[0018] Corresponding reference characters indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF INVENTION
[0019] The following detailed description illustrates the invention
by way of example and not by way of limitation. This description
will clearly enable one skilled in the art to make and use the
invention, and describes several embodiments, adaptations,
variations, alternatives and uses of the invention, including what
I presently believe is the best mode of carrying out the invention.
As various changes could be made in the above constructions without
departing from the scope of the invention, it is intended that all
matter contained in the above description or shown in the
accompanying drawings shall be interpreted as illustrative and not
in a limiting sense.
[0020] Referring to the drawings, an electric fuel pump for use
with automotive vehicles is indicated generally 10. Pump 10 is a
two-stage turbine pump having an inlet section 12, a fuel pumping
section 14 including a first pump stage 14a and a second pump stage
14b, a housing 16 in which is housed a pump motor 17 (see FIG. 7),
and an outlet section 18 in which a fuel outlet 19 is formed.
[0021] Inlet section 12 comprises an end cap 13 which is of a
molded plastic material and has formed therein a fuel inlet 20 by
which fuel at a low pressure is drawn into the pump from a fuel
tank (not shown). Pump section 14a comprises end cap 13 and a port
plate 22a. Pump section 14b includes also includes port plate 22a,
and a casing 22b. The port plate and casing are each formed of a
molded plastic material and are arranged in a stacked configuration
with port plate 22a mounted between end cap 13 and casing 22b. Each
pump section further includes an impeller, 24a, 24b respectively.
The port plate and casing are each formed with central cavities in
which the respective impellers are rotatably installed, the
impellers each being mounted on a shaft 26 of the pump motor 17. As
shown in FIGS. 3A and 3B, casing 22b is first fitted over shaft 26,
then impeller 24b is mounted on the shaft. Next, an impeller drive
28 is fitted onto the shaft. Port plate 22a is then fitted over
shaft 26, and impeller 24a is then mounted onto the shaft. Finally,
end cap 13 is fitted onto the outer end of the shaft, the end cap
having a housing 30 formed therein in which the outer end of shaft
26 is received.
[0022] Operation of a two-stage turbine pump is known in the art.
Fuel is drawn into the pump through inlet 20 in end cap 13, and
drawn to the first and lower pressure stage of the pump by impeller
24a. From this first stage, the fuel is drawn into the higher
pressure second pump stage by impeller 24b. Port plate 22a has a
flow path 23 formed therein (see FIG. 3A) by which fuels flows from
the first to the second pump stage. Similarly, casing 22b has a
flow path formed therein (not shown) by which high pressure fuel is
directed from the second pump stage to pump outlet 19 via an outlet
21 in the casing. Tabs 31 are formed on the outer margin of casing
22b, the tabs fitting in slots 16s in housing 16 to aid in assembly
of the fuel pump.
[0023] For proper and efficient operation of fuel pump 10, the
various components comprising the turbine assembly need to be
properly aligned and precisely fitted together.
[0024] Referring to FIGS. 5-8, end cap 13, and port plate 22a, and
casing 22b are held together during assembly using a pair of spring
pins 32. As shown in FIGS. 4A-4D, each spring pin is of a hollow,
elongate cylindrical shape with a longitudinal slot 34 extending
the entire length of the pin. The pins are formed of a spring
material such as a spring steel. The length of each pin is such
that it extends between end cap 13, through port plate 22a, and
into casing 22b. This is as shown in FIGS. 2A and 2B.
[0025] Because it is important to not cause cracking in these
components after the pump is assembled, the present invention
includes open channels formed in the sidewall of end plate 13 and
port plate 22a, and casing 22b for receiving the pins 32. In FIG.
5, an open sided pocket or recess 36 is shown to be formed in end
plate 13. A similar open sided pocket or recess 38 is formed in
casing 22b. Each pocket comprises a semi-circular opening formed in
the outer wall of the end cap or port plate respectively, the
opening extending from an inner face 40 of end cap 13, or an inner
face 42 of casing 22b, into the body of the respective part. In
each part, the depth of the pocket is approximately one-half the
thickness of the part; while, the diameter of the pocket generally
corresponds to that of the spring pin.
[0026] Port plate 22a has opposed channels 44a, 44b formed therein
through which the pins 32 are inserted when fuel pump 10 is
assembled. The diameter of each channel corresponds to that of the
spring pin inserted through the channel. Both channels open into
the outer face or sidewall of the port plate. Thus, while the
channels facilitate insertion of the spring pins for accurately
aligning the pump components; they encapsulate the spring pins,
while the pockets 36, 38 do not encapsulate them. Channels 44a, 44b
in the outer wall of port plate 22a have the advantage of allowing
forces transmitted through the spring pins, when shocks and
vibrations occur, to dissipate through the end cap and port plate,
rather than cracking radially to the outside of the port plate.
Preferably the open channels formed in end cap 13, port plate 22a,
and casing 22b, for receiving the spring pins, are approximately
five degrees (5.degree.) less than being diametrically opposite
each other. This facilitates correct alignment of the parts during
assembly.
[0027] During manufacture of the fuel pump, the spring pins 32 are
first installed in the respective channels in port plate 22a. The
pins are inserted so that the ends of the pins extend from opposite
sides of the port plate. Next, the various components comprising
the two stages of the turbine pump are mounted on motor shaft 26.
Casing 22b is first rotated until the tabs 31 formed on the outer
face of the port plate align with the slots 16s in the housing 16
in which pump motor 17 is housed. Housing 16 and casing 22b are
then correctly aligned. Next, impeller 24b is installed on shaft
26, with impeller drive 28 then being fitted onto the shaft. At
this time, the inner ends of the spring pins 32 are inserted into
the respective pockets 38 formed in the casing. Next, impeller 24a
is mounted on shaft 26. End cap 13 is then rotated until the
pockets 36 formed in the end cap align with the channels 44a, 44b
in port plate 22a. When they are, the end cap is properly held in
alignment with port plate 22a for the outer ends of the spring pins
received in the pockets 36.
[0028] The spring pins are slightly compressed when they are
installed in port plate 22a. During the final stages of pump
assembly, when an outer shell (not shown) of pump 10 is fitted into
place, the expansion force exerted by the springs against the
sidewalls of the channels 44a, 44b and the slip fit of the pins
with the pockets 36, 38 hold these components tightly together so
to retain the proper alignment between the pump inlet, the first
and second pump stages, and the pump outlet. Importantly, because
the channels and pockets are open sided rather than completely
enclosing and encapsulating the spring pins, forces which otherwise
could damage the end cap and port plates are readily distributed
through these parts and not concentrated about the channels where
damage could occur.
[0029] In view of the above, it will be seen that the several
objects and advantages of the present invention have been achieved
and other advantageous results have been obtained.
* * * * *