Note: Descriptions are shown in the official language in which they were submitted.
FUEL DELIVERY SYSTEMS AND METHODS
FIELD
Fuel delivery systems.
BACKGROUND
Diesel engines for over-the-road vehicles, such as Class 8 trucks, typically
employ
a fuel injection pump to distribute fuel from a vehicle's fuel tank to a high-
pressure rail of
a fuel delivery system. The fuel pump, as well as other accessories, such as
the power
steering pump, air compressor, etc., are typically driven by rotation of the
diesel engine
via pulleys, gears or other similar transmissions. In current vehicles, the
fuel injection
pump is always engaged, and will operate as long as the engine's crankshaft or
camshaft
is spinning.
Diesel engines of this type also include a secondary hand pump, which is used
for
priming the fuel delivery system in such cases as when the vehicle is operated
to an
empty state (i.e., the fuel tank and delivery system is dry) or when the fuel
is drained for
vehicle service.
SUMMARY
Embodiments of the present disclosure are directed to fuel delivery systems or
fuel injection pumps of fuel delivery systems that aim to provide the above
described
functionality without the need for the secondary hand pump. Embodiments of the
present
disclosure are also directed to methods of using the improved fuel delivery
systems or
fuel injection pumps of fuel delivery systems.
In accordance with one or more aspects of the present disclosure, a method is
provided for priming a fuel delivery system of a vehicle having an internal
combustion
engine. The fuel delivery system has a fuel source, an injection pump, and at
least one
fuel injector. The method comprises adding fuel to the fuel delivery system
when the
internal combustion engine is in the non-running state, and thereafter
rotating a drive
shaft of the injection pump in a pump direction via operator input.
In some embodiments, rotating a drive shaft of an injection pump includes
connecting a drive tool to an end of said drive shaft such that the drive tool
and the drive
shaft are connected for co-rotation.
PC CR \ 046-236 PalLnt application tLxt 1 -
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In some embodiments, connecting a drive tool to an end of said drive shaft
includes keying the drive tool to the drive shaft.
In some embodiments, the drive tool is selected from a group consisting of a
wrench and a crank lever.
In accordance with another aspect of the present disclosure, an injection pump
of
a fuel delivery system is provided. The injection pump comprises an injection
pump
housing, a pump mechanism disposed within the housing, a fuel input, such as
an input
port, configured to be connectable to a source of fuel at a first pressure, a
fuel output,
such as an output port, configured to be connectable to at least one fuel
injector, and a
transmission interface configured to be coupled in driving relationship with
an internal
combustion engine. The injection pump also includes a pump drive shaft
rotatable
supported by the injection pump housing and operatively coupled to the pump
mechanism. In embodiments of the present disclosure, rotation of the pump
drive shaft
transmits fuel supplied to the input port at a first pressure to the fuel
output port at a
second, higher pressure. The injection pump further includes a one-way clutch
arrangement coupled between the transmission interface and the pump drive
shaft. In
some embodiments, the one-way clutch arrangement is configured such that: (1)
torque
transmitted to the transmission interface by the internal combustion engine in
a first
rotational direction is transferred to the pump drive shaft; and (2) torque
transmitted to
the drive shaft in the first direction via operator input is not transferred
to the
transmission interface.
In some embodiments, the transmission interface includes one of a gear and a
pulley.
In some embodiments, the one-way clutch arrangement includes a device selected
from the group consisting of a one-way concentric roller bearing, a sprag
clutch, and a
ratchet clutch.
In some embodiments, a section of the pump drive shaft extends externally of
the
injection pump housing. In some of these embodiments, the section of the pump
drive
shaft is configured to be engaged by a drive tool. In some embodiments, the
section of the
pump drive shaft includes one of a keyed, splined , polygonal socket.
This summary is provided to introduce a selection of concepts in a simplified
form that are further described below in the Detailed Description. This
summary is not
PCCR 046-236 Patent application text -2-
CA 3068162 2020-01-16
intended to identify key features of the claimed subject matter, nor is it
intended to be
used as an aid in determining the scope of the claimed subject matter.
DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of the claimed
subject matter will become more readily appreciated as the same become better
understood by reference to the following detailed description, when taken in
conjunction
with the accompanying drawings, wherein:
FIGURE 1 is a schematic representation of one example of a fuel delivery
system
in accordance with an aspect of the present disclosure;
FIGURE 2 is a schematic representation of one example of an injection pump in
accordance with an aspect of the present disclosure;
FIGURE 3A and FIGURE 3B are cross-sectional views of one example of a
one-way bearing in accordance with an aspect of the present disclosure.
DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended
drawings where like numerals reference like elements is intended as a
description of
various embodiments of the disclosed subject matter and is not intended to
represent the
only embodiments. Each embodiment described in this disclosure is provided
merely as
an example or illustration and should not be construed as preferred or
advantageous over
other embodiments. The illustrative examples provided herein are not intended
to be
exhaustive or to limit the claimed subject matter to the precise forms
disclosed. Similarly,
any steps described herein may be interchangeable with other steps, or
combinations of
steps, in order to achieve the same or substantially similar result.
In the following description, numerous specific details are set forth in order
to
provide a thorough understanding of exemplary embodiments of the present
disclosure. It
will be apparent to one skilled in the art, however, that many embodiments of
the present
disclosure may be practiced without some or all of the specific details. In
some instances,
well-known process steps have not been described in detail in order not to
unnecessarily
obscure various aspects of the present disclosure. It will be appreciated that
embodiments
of the present disclosure may employ any combination of features described
herein.
Embodiments of the present disclosure are generally directed to fuel delivery
systems, or fuel injection pumps, suitable for use in vehicles, such as Class
8 trucks, that
PCCR 046-216 Patult appItcation text CA 3068162 3068162 2020-01-16
employ internal combustion engines (ICE), such as spark ignition engines or
compression
ignition engines. Although exemplary embodiments of the present disclosure
will be
described hereinafter with reference to a diesel vehicle, such as a heavy duty
truck, it will
be appreciated that aspects of the present disclosure have wide application,
and therefore,
may be suitable for use with many other types of vehicles that employ engine
driven fuel
pumps, including but not limited to light & medium duty vehicles, passenger
vehicles,
motor homes, buses, commercial vehicles, marine vessels, et. Accordingly, the
following
descriptions and illustrations herein should be considered illustrative in
nature, and thus,
not limiting the scope of the present disclosure, as claimed.
Generally described, embodiments of the present disclosure are directed to an
improved fuel injection pump for an internal combustion engine (e.g., diesel
engine)
configured such that the secondary hand pump of the prior art, typically used
for priming,
can be eliminated. To achieve this result, representative embodiments of the
present
disclosure employ a one-way bearing or clutch on, for example, the input side
of the drive
shaft of the injection pump. By employing a one-way bearing or clutch, such as
of the
concentric roller type, or other suitable clutch, in this manner the fuel
injection pump can
be: (1) operated by direct coupling of the engine and the drive shaft of the
fuel injection;
and (2) once the engine is stopped, the drive shaft of the fuel injection pump
can be
manually driven in order to prime the system. Accordingly, by locating a one-
way
bearing or similar clutch device along the driveline of the fuel injection
pump, the fuel
injection pump can be both manually operated when the engine is shut off and
automatically driven when the engine is running.
In some embodiments of the present disclosure, the fuel injection pump is
configured for user access of the drive shaft in order to impart rotational
movement
thereto. In some embodiment, the end of the drive shaft is exposed externally
of the fuel
pump housing so that, with a built-in hex socket or other key-type feature,
the drive shaft
can be manually turned with a hand crank, a power drill (e.g., hydraulic,
pneumatic,
electric, etc.), etc. In other embodiments, the end of the drive shaft can be
coupled to a
drive assembly that can be selectively connected (via a suitable clutch
arrangement) to an
external power supply, such as an electric motor, a pneumatic motor, etc.
Referring now to FIGURE I, there is shown a schematic representation of a
representative fuel delivery system, generally designated 20, in accordance
with aspect of
PCCR 046-236 Patent application text CA 3068162 3068162 2020-01-16
the present disclosure. As shown FIGURE 1, the fuel delivery system 20
includes a low
pressure side 22 and a high pressure side 24. The low pressure side 22 of the
fuel delivery
system includes a fuel reservoir, tank or other fuel source 28 connected via a
fuel supply
line 30 to a fuel filter 32, sometimes referred to as a fuel separator in
diesel engines. The
fuel filter 32, in turn, is connected to the input port of a primary or
injection pump 36 via
fuel supply line 38. One or more optional lift pumps 40, sometimes referred to
as sending
units, can be used to pump fuel from the fuel source 28 to the fuel filter 32,
and in some
embodiments, through the fuel filter to the injection pump 36.
In the embodiment shown, the high pressure side 24 of the fuel delivery system
20
includes a fuel distribution unit 46, shown as a common rail, connected to the
output port
of the injector pump 36 via supply line 48. The fuel distribution unit 46, in
turn, is
connected to a plurality of fuel injectors 50 via rail lines 52.
Alternatively, each fuel
injector 50 is connected to the injection pump 36 via a separate high pressure
supply line.
In any case, the fuel injectors 50 distribute pressurized fuel from the
injection pump 36 to
associated combustion chambers of an ICE 56. In some embodiments, the fuel
injectors 50 include a piezoelectric or solenoid valve or other controllable
device that can
be used to control the amount and timing of the fuel injected into the
combustion
chamber. Any unused fuel from the fuel distribution unit 46 (or fuel injectors
in some
embodiments) can be returned to the fuel source 28 via a return line 58. In
the
embodiment shown, the injection pump 36 is driven (e.g., gear, belt, chain,
etc.) via
the ICE 56 through transmission interface 60 (e.g., a drive gear, a pulley
with integrated
shaft, etc.)
Turning now to FIGURE 2, there is shown a schematic representation of an
embodiment of the injection pump 36. As shown in FIGURE 2, the injection pump
36
includes a fuel input port 66 and a fuel output port 68. The injection pump 36
also
includes a drive shaft 70 coupled in-between the transmission interface 60 and
the pump
mechanism 76 of the injection pump 36. In embodiments of the present
disclosure, the
pump mechanism 76 can be of the vane-type, of the piston/plunger type, etc. In
embodiments where the pump mechanism is of the piston/plunger type, a rotary
to
reciprocating mechanism, such as a camshaft, a cam follower and spring, move
the
piston/plunger in a reciprocating motion to pump the fuel. In any case,
rotation of the
drive shaft 70 causes pumping action of the pump mechanism of the injection
pump 36
PCCR 046-236 Patent apphcanon text CA 3068162 3068162 2020-01-16
for raising the low pressure fuel at the input port 66 to a higher pressure
fuel at the output
port 68 and the pressurization of the fuel distribution unit 46.
In accordance with an aspect of the present disclosure, a one-way clutch or
bearing 78 or other suitable overrunning clutch arrangement is operatively
connected
between the transmission interface 60 and the drive shaft 70. In use, the one-
way clutch
or bearing 78, such as of the concentric roller type (see FIGURE 3), the sprag
type, the
ratchet type, etc., is configured to allow direct coupling of the engine
driven transmission
interface 60 and the drive shaft 70 of the injection pump 36 such that
rotation of the ICE's
crankshaft, camshaft, etc., affects rotation of the drive shaft 70 in a drive
direction
(e.g., clockwise), thereby operating the injection pump 36 via power from the
ICE 56.
With this configuration, once the engine is stopped, the one-way bearing 78
also provides
for the injection pump 36 to be manually driven via the drive shaft 70 in the
same
direction (e.g., clockwise) in order to prime the fuel delivery system without
engagement
of the engine.
One example of a one-way bearing 78, such as of the concentric roller type, is
illustrated in FIGURE 3. As shown in FIGURE 3, the transmission interface
(e.g., drive
gear, pulley/shaft, etc.) is provided with a hub 90 which encircles the drive
shaft 70 and is
rotatable relative thereto. A hub or sleeve 92 is keyed or otherwise fixed for
co-rotation
with the drive shaft 70. The hub or sleeve 92 is provided with angularly
spaced inclined
notches 94 in which are positioned rollers 96. The rollers 96 are urged into
engagement
with the inner surface 98 of the hub 90 by springs 100. These rollers 96
provide an
overrunning clutch which permits the drive shaft 70 to rotate freely in one
direction. In
use, the overrunning clutch permits rotation (clockwise as shown by arrow 104)
of the
hub 90 to drive the drive shaft 70 in the clockwise direction (as shown by
arrow 106), as
shown in FIGURE 3A. In further use, the overrunning clutch permits free
rotation of the
drive shaft 70 in the clockwise direction (as shown by arrow 110 in FIGURE 3B)
by
external means, such as a manual tool, etc., without engaging the hub 90. In
other words,
when the drive shaft 70 is driven in the clockwise direction, the hub 90
remains stationary
as no torque is transferred by the overrunning clutch from the drive shaft 70
to the
hub 90. As such, the drive shaft 70 can be driven, for example manually,
without
imparting torque onto the engine of the vehicle.
PCCR \ (46-236 Patent application text CA 3068162 3068162 2020-01-16
In some embodiments, the drive shaft 70 (shown in FIGURE 2) extends externally
of the injection pump housing, the end 72 of which is accessible to the
operator or
technician when, for example, the vehicle hood is open. In other embodiments,
the end of
the drive shaft 72 is accessible through the housing. In any case, to
facilitate manual
rotation, the end of the drive shaft 70 is formed with an inner bore 74 that
is keyed,
splined, or otherwise forms a socket (e.g., hexagonal) or other suitable
configuration for
cooperative rotatable engagement with a drive tool, such as a hand crank. In
other
embodiments, the outer circumference of the drive shaft 70 towards the end
thereof can
be formed with a hex bolt head or other configuration that can be engaged and
rotated by
a drive tool, such as a wrench, etc. In other embodiments, a gear can be keyed
or
otherwise fixed for rotation to the outer perimeter of the drive shaft 70. In
these
embodiments, the gear can be selectively engageable and rotatable by a powered
priming
motor, such as an electric motor, a hydraulic or pneumatic motor, etc.
The configuration of the injection pump with the one-way bearing provides one
or
more advantages over the prior art. For example, in situations where the
vehicle has been
operated to the fuel empty state, wherein the fuel filter and fuel source are
dry, when the
fuel system has been drained for service (e.g., fuel filter replacement,
etc.), etc., the
injection pump 36 can be operated to prime the fuel delivery system without
use of
the ICE. For example, once fuel as added to the system, e.g., to the fuel
source 28 and/or
into the fuel filter 32, etc., the operator or technician can rotate the drive
shaft 70 via a
suitable drive tool (in the clockwise direction in the embodiments shown,
although the
one-way bearing can be configured to overrun in the counterclockwise
direction).
Rotation of the drive shaft 70 via the drive tool operates the pump mechanism
76 of the
injection pump 36 to draw fuel through the fuel filter and/or to pressurize
the fuel for
distribution by the fuel distribution unit 46. Operation of the injection pump
36 may also
bleed off any air present in the system. In some embodiments, the lift pumps
can be
operated separate from the ignition switch to aid in the supply of fuel from
the fuel
source 28 to the injection pump 36. Once the operator turns over the engine,
and the
engine begins to run, the injection pump 36 once again is driven by the engine
via the
transmission interface 60. Thus, the fuel delivery system can be primed with
the injection
pump 36 without need of a secondary hand pump. Once the engine is turned off
again,
the drive shaft 70 can then again be rotated manually with a drive tool.
PC CR \ 0,16-236 Patent application ti,t -7-
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It should be noted that for purposes of this disclosure, terminology such as
"upper," "lower," "vertical," "horizontal," "fore," "aft," "inner," "outer,"
"front," "rear,"
etc., should be construed as descriptive and not limiting the scope of the
claimed subject
matter. Further, the use of "including," "comprising," or "having" and
variations thereof
herein is meant to encompass the items listed thereafter and equivalents
thereof as well as
additional items. Unless limited otherwise, the terms "connected," "coupled,"
and
variations thereof herein are used broadly and encompass direct and indirect
physical or
electrical connections or couplings. For the purposes of the present
disclosure, the phrase
"A and/or B" means "(A), (B), or (A and B)." For the purposes of the present
disclosure,
the phrase "at least one of A, B, and C" means "(A), (B), (C), (A and B), (A
and C),
(B and C), or (A, B and C)."
The principles, representative embodiments, and modes of operation of the
present disclosure have been described in the foregoing description. However,
aspects of
the present disclosure which are intended to be protected are not to be
construed as
limited to the particular embodiments disclosed. Further, the embodiments
described
herein are to be regarded as illustrative rather than restrictive. It will be
appreciated that
variations and changes may be made by others, and equivalents employed,
without
departing from the spirit of the present disclosure. Accordingly, it is
expressly intended
that all such variations, changes, and equivalents fall within the spirit and
scope of the
present disclosure, as claimed.
PCCR 046-236 Patent applwation text -8-
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