Information
-
Patent Grant
-
6527603
-
Patent Number
6,527,603
-
Date Filed
Wednesday, March 7, 200123 years ago
-
Date Issued
Tuesday, March 4, 200321 years ago
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Inventors
-
Original Assignees
-
Examiners
- Morano; S. Joseph
- Vasudeva; Ajay
Agents
-
CPC
-
US Classifications
Field of Search
US
- 440 88
- 123 516
- 123 509
- 123 510
- 137 265
-
International Classifications
-
Abstract
A fuel system for a marine propulsion system includes a reservoir that defines a cavity in which first and second fuel pumps are disposed. The first fuel pump is a lift pump which draws fuel from a fuel tank and pumps the fuel into the cavity of the reservoir. The second fuel pump is a high pressure pump which draws fuel from the cavity and pumps the fuel at a higher pressure to a fuel rail of an engine.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally related to a fuel system for a marine propulsion system and, more particularly, to a fuel system that provides a fuel reservoir in which two pumps, a lift pump and a high pressure pump, are housed and disposed within a volume of fuel stored in the fuel reservoir.
2. Description of the Prior Art
Many different types of fuel delivery systems are known to those skilled in the art for use with marine propulsion systems. Certain fuel delivery systems incorporate fuel vapor separators, which act as a reservoir and a mechanism for separating fuel vapor from liquid fuel.
U.S. Pat. No. 5,819,711, which issued to Motose on Oct. 13, 1998, describes a vapor separator for a fuel injected engine. The fuel injection system of an engine, and particularly an outboard motor, includes a fuel vapor separator that is disposed on one side of the throttle bodies at the front of the engine. The fuel vapor separator is comprised of a housing assembly having a cover plate in which an integral fuel inlet fitting, an integral fuel outlet fitting, an integral vent fitting and an integral fuel return fitting are formed. The fuel injectors for the engine are disposed on the opposite side of the throttle bodies from the fuel vapor separator and are supplied with fuel through a vertically extending fuel rail. The pressure regulator is positioned at the top of the fuel rail and the fuel rail is directly affixed to the throttle bodies.
U.S. Pat. No. 5,375,578 which issued to Kato et al on Dec. 27, 1994, describes a high pressure fuel feeding device for a fuel injection engine. The injection system for an outboard motor includes a vapor fuel separator that has a fuel chamber in which the supply of fuel is maintained by a float valve and an air chamber positioned above the fuel chamber and to one side of it and which communicates with the fuel chamber through a perforated member. A fuel media fills the air chamber and an atmospheric air inlet is provided to the air chamber. Fuel pressure and fuel regulator valves are disposed in the area to the side of the air chamber and regulate fuel and air pressure by dumping fuel and air back to the fuel and air chambers, respectively, through integral internal conduits. The regulating system includes an arrangement for regulating the fuel pressure so that it will be at least greater than the air pressure by a predetermined amount and also for precluding the delivery of air under pressure if fuel under pressure is not supplied.
U.S. Pat. No. 5,579,740, which issued to Cotton et al on Dec. 3, 1996, describes a fuel handling system. The system is intended for use with an internal combustion engine having a vapor separator for receiving fuel from a remote tank and a pump for delivering the fuel under high pressure to a fuel injector of the engine while providing vapor separation. The separator has an inlet for receiving fuel from the tank, an outlet for enabling fuel to be removed and delivered to the engine, at least one return for enabling fuel not used by the engine to be returned to the separator, and a vent for removing fuel vapor from a gas dome above a pool of liquid fuel within the separator. The inlet has a valve controlled by a float in the reservoir for admitting fuel to maintain the level of liquid fuel in the separator. To retard foaming and excessive vaporization of liquid fuel in the separator, the separator has a perforate baffle between any return and the liquid fuel pool.
U.S. Pat. No. 5,404,858, which issued to Kato on Apr. 11, 1995, describes a high pressure fuel feeding device for a fuel injection engine. An outboard motor is provided with a fuel injection system in which all of the major components of the fuel portion of the fuel/air injection system are contained within a sealed chamber having a fuel drain and the conduits that supply fuel to the fuel injectors are also contained within the fuel collecting conduits so that any fuel leaking will not escape to the atmosphere. In addition, the air pressure supplied to the fuel/air injectors is regulated and the air relieved for pressure regulation is returned to an air inlet device having a baffle for condensing any fuel in the regulated air and returning the condensed fuel to a vapor separator.
U.S. Pat. No. 5,389,245, which issued to Jaeger et al on Feb. 14, 1995, discloses a vapor separating unit for a fuel system. The vapor separating unit has particular application to a fuel system for a marine engine. The vapor separating unit includes a closed tank having a fuel inlet through which fuel is fed to the tank by a diaphragm pump. The liquid level in the tank is controlled by float-operated valve. An electric pump is located within the vapor separating tank and has an inlet disposed in the tank and an outlet connected to a fuel rail assembly of the engine. Excess fuel from the fuel rail assembly is conducted back to the upper end of the vapor separator tank. A vapor venting mechanism is incorporated in the tank to vent vapor from the tank.
U.S. Pat. No. 5,368,001, which issued to Roche on Nov. 29, 1994, describes a fuel handling system for an internal combustion engine which has a reservoir for receiving fuel under low pressure from a remote gas tank and a fuel pump for delivering the fuel under high pressure to a fuel injector of the engine while providing vapor separation. The reservoir has an inlet for receiving fuel from the tank, an outlet for removing fuel from the reservoir and delivering it to the engine, a fuel return for returning fuel not used by the engine, a drain for removing water, and a vapor vent for removing fuel vapors from a gas dome above the liquid within the reservoir. The inlet has a valve controlled by a float in the reservoir for admitting fuel to maintain the level of liquid in the reservoir so that the pump is supplied with fuel. To remove fuel, a fuel pickup is coupled to an inlet of the pump which has its outlet coupled to the reservoir outlet. The pickup has a diaphragm for filtering fuel entering the pump while preferably preventing the admission of gas or water. Preferably, a water sensor in the reservoir provides an electrical signal when it is immersed in water so that the drain can be opened to remove the water, preferably before the pickup is immersed and fuel flow to the pump and engine is cut off.
U.S. Pat. No. 5,103,793, which issued to Riese et al on Apr. 14, 1992, discloses a vapor separator for an internal combustion engine. The vapor separator includes a bowl member and a cover member. A fuel pump is located in the internal cavity of the bowl member and has its inlet located in the lower portion of the bowl member cavity, for supplying fuel thereto. The fuel pump is secured in position within the bowl member by engagement of the cover member with the fuel pump. The cover member includes a mounting portion for mounting a water separating filter element to the vapor separator assembly. The cover member includes structure for routing fuel from the discharge of the water separating filter element to the interior of the bowl member internal cavity. A compact arrangement is thus provided for the vapor separator, the fuel pump, and the water separating filter, eliminating a number of hose connections between such components as well as facilitating assembly of the engine.
U.S. Pat. No. 5,309, 885, which issued to Rawlings et al on May 10, 1994, describes a marine propulsion device including a fuel injected, four-cycle internal combustion engine. The internal combustion engine comprises an engine block including a combustion chamber, a fuel vapor separator, a fuel supply mechanism for introducing fuel to the combustion chamber, a conduit communicating between the fuel vapor separator and the fuel supply mechanism for introducing fuel, and a cooling jacket for cooling the fuel vapor separator.
U.S. Pat. No. 6,170,470 B1, which issued to Clarkson et al on Jan. 9, 2001, discloses a fuel supply system for an internal combustion engine. The fuel system provides first and second conduits that draw fuel from first and second positions, or locations, within a fuel reservoir. If water exists in the fuel reservoir, the second position is selected to be lower in the fuel reservoir than the first position so that accumulated water will be drawn through the second conduit under certain conditions, such as when the engine is operating at a speed above the minimum threshold. The fuel reservoir can be a fuel tank or auxiliary fuel tank of a vehicle or watercraft or, alternatively, it can be the housing of a fuel/water separator.
U.S. patent application Ser. No. 09/550,720 which was filed by Wickman et al on Apr. 17, 2000 and assigned to the assignee of the present application, discloses a fuel supply method for a marine propulsion engine. The method for controlling the operation of a fuel system of an outboard motor uses a lift pump to transfer fuel from a remote tank to a vapor separator tank. Only one level sensor is provided in the vapor separator tank and an engine control unit monitors the total fuel usage subsequent to the most recent filling of the tank. When the fuel usage indicates that the fuel level in the vapor separator tank has reached a predefined lower level, a lift pump is activated to draw fuel from a remote tank and provide that fuel to the vapor separator tank.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
In marine propulsion systems, and particularly in outboard motors, it is advantageous if components can be packaged in a way that reduces the required volume for the assembly of components. It is also advantageous if the components of a fuel delivery system for a marine propulsion system can be cooled in a way that prevents the vaporization of liquid fuel in response to heat being transmitted to the fuel components.
SUMMARY OF THE INVENTION
A fuel system for a marine propulsion system, made in accordance with the preferred embodiment of the present invention, comprises a reservoir having a cavity for containing liquid fuel for use by the marine propulsion system. It also comprises a first pump for drawing fuel from a fuel supply and pumping the fuel at a first pressure magnitude into the cavity. The first pump is disposed within the cavity and in thermal communication with the liquid fuel. The present invention further comprises a second pump for drawing the fuel from the cavity and pumping the fuel at a second pressure magnitude to an engine of the marine propulsion system. The second pump is disposed within the cavity and in thermal communication with the liquid fuel.
The present invention, in a preferred embodiment, further comprises a fuel tank that is connected as a fuel supply to an inlet of the first pump. A fuel filter is connected in fluid communication between the first tank and the first pump. The fuel filter can be a water separating fuel filter.
In certain embodiments of the present invention used in conjunction with fuel injected engines, the present invention further comprises a fuel rail connected in fluid communication with an outlet of the second pump. The fuel rail is connected in fluid communication with a plurality of fuel injectors which inject fuel either into a intake manifold of the engine or, in direct fuel injected (DFI) engines, directly into the combustion chambers of the engines.
A preferred embodiment of the present invention further comprises a fuel return line connected in fluid communication between an outlet of the fuel rail and the reservoir. A preferred embodiment of the present invention further comprises a pressure regulator connected between the outlet of the fuel rail and the reservoir in order to maintain a preselected pressure within the fuel rail. The pressure regulator is connected in fluid communication with an air intake manifold of the marine propulsion system in order to provide a reference pressure for the regulator. The preselected pressure within the fuel rail can be a preselected differential pressure magnitude above an air pressure within the air intake manifold of the engine.
The present invention can also comprise a fuel level sensor disposed within the reservoir to detect a fuel level within the reservoir. An engine control module (ECM) can be connected in signal communication with the first pump and in signal communication with the fuel reservoir, in order to turn the first pump on and off as a function of the level of liquid fuel within the reservoir.
In a preferred embodiment of the present invention, the first pressure magnitude is less than the second pressure magnitude and the marine propulsion system is an outboard motor. The reservoir, in one alternative embodiment of the present invention, is attached for support to a driveshaft housing of the outboard motor and, as a result of this location, the reservoir is at least partially submerged in water when a propeller of the marine propulsion system is not rotating.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully and completely understood from a reading of the description of the preferred embodiment in conjunction with the drawings, in which:
FIG. 1
is a schematic representation of a fuel system for a marine propulsion system made in accordance with the present invention;
FIG. 2
is a section view of a reservoir of the present invention; and
FIG. 3
shows the reservoir of the present invention mounted for support to a midsection of an outboard motor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Throughout the description of the preferred embodiment of the present invention, like components will be identified by like reference numerals.
In
FIG. 1
, the fuel system for a marine propulsion system, made in accordance with the preferred embodiment of the present invention, is represented schematically. A reservoir
10
encloses a cavity
12
for containing liquid fuel
16
for use by the marine propulsion system and, more particularly, for use by an engine of the marine propulsion system. A first pump
20
is provided for drawing fuel from a fuel supply, such as the fuel tank
22
, and for pumping the fuel at a first pressure magnitude into the cavity
12
. The fuel is drawn by the first pump
20
into in its inlet
24
and pumped out of its outlet
26
. In the embodiment shown in
FIG. 1
, a conduit
28
is provided to direct the fuel, at the first pressure magnitude, toward the bottom portion of the cavity
12
.
A second pump
30
is provided for drawing fuel from the cavity
12
and pumping the fuel at a second pressure to an engine of the marine propulsion system. The engine is represented in
FIG. 1
as the fuel rail
40
and an air intake manifold
42
which is represented by a dashed line. The fuel rail provides fuel to a plurality of fuel injectors
44
which inject fuel into the air intake manifold
42
. Although the engine of a marine propulsion system comprises many other components, those components are not directly related to the present invention and are therefore not illustrated specifically in FIG.
1
.
The liquid fuel is drawn into the inlet
32
of the second pump
30
and pumped out of the outlet
34
, as represented by line
36
which can be a suitable conduit connected between the outlet of the second pump
30
and an inlet
46
of the fuel rail
40
. As can be seen in
FIG. 1
, both the first and second pumps,
20
and
30
, are disposed within the cavity
12
of the reservoir
10
and disposed in thermal communication with the fuel
16
when the liquid fuel is within the cavity
12
. This relationship between the first and second pumps,
20
and
30
, and the fuel
16
provides for thermal exchange between the pumps and the liquid fuel. In a preferred embodiment of the present invention both the first and second pumps,
20
and
30
, are driven by electric motors. However, this is not a required characteristic of the pumps in all alternate embodiments.
With continued reference to
FIG. 1
, it can be seen that the fuel tank
22
is connected, as a fuel supply, to the inlet
24
of the first pump
20
. A fuel filter
50
is shown connected in fluid communication between the fuel tank
22
and the first pump
20
. This fuel filter
50
can be a water separating fuel filter in a preferred embodiment of the present invention.
The fuel rail
40
is connected in fluid communication with the outlet
34
of the second pump
30
and also in fluid communication with the plurality of fuel injectors
44
, as illustrated schematically in
FIG. 1. A
fuel return line
60
is connected in fluid communication between an outlet
48
of the fuel rail
40
and the reservoir
10
. More specifically, a pressure regulator
64
is connected between the outlet
48
of the fuel rail
40
and the reservoir
10
in order to maintain a preselected pressure within the fuel rail
40
. The pressure regulator
64
can be connected in fluid communication with the air intake manifold
42
of the marine propulsion system and the preselected pressure provided within the fuel rail
40
can be a preselected differential pressure magnitude above the air pressure within the air intake manifold
42
. Dashed line
66
represents the connection between the air intake manifold
42
and a reference pressure inlet
68
of the pressure regulator
64
. As a result, the pressure regulator
64
maintains a pressure within the fuel rail
40
that is a preselected magnitude greater than the pressure in line
66
. Excessive pressure, provided by the second pump
30
, is relieved by allowing the fuel to flow back into the cavity
12
of the reservoir
10
, as represented by arrow
60
.
A preferred embodiment of the present invention also comprises a fuel level sensor
70
that is disposed within the reservoir
10
to detect a fuel level
72
within the cavity
12
of the reservoir
10
. An engine control module (ECM)
80
is connected in signal communication with the first pump
20
, as represented by line
82
, and in signal communication with the fuel level sensor
70
, as represented by line
84
. In this way, the fuel level sensor
70
provides information on line
84
to the engine control module
80
which can represent the fact that the fuel level
72
has dropped below a preselected magnitude. When the engine control module
80
receives this signal, it provides a signal on line
82
to the first pump
20
to activate the first pump and draw more fuel from the fuel tank
22
and pump that fuel into the cavity
12
of the reservoir
10
. In this way, the engine control module
80
can maintain the level
72
of liquid fuel
16
within a predetermined range.
With continued reference to
FIG. 1
, the first pressure magnitude at the outlet
26
of the first pump
20
is typically very low since it is intended to be used as a lift pump to draw fuel from a fuel tank to the reservoir and the second pressure magnitude at the outlet
34
of the second pump
30
is typically in the range of 30 PSI to 90 PSI, depending on the application and on the type of engine used.
FIG. 2
is a section view of the reservoir
10
illustrated to show the components located within the cavity
12
of the reservoir
10
. The first pump
20
, the fuel level sensor
70
and the second pump
30
are all shown within the cavity
12
of the reservoir
10
. In the representation of
FIG. 2
, the reservoir
10
comprises a lower portion
90
and an upper portion
92
that are bolted together to define the reservoir
10
. The reservoir, in turn, is attached by a plurality of bolts, at location
93
, to the marine propulsion system. In one embodiment of the present invention, which will be described in greater detail below in conjunction with
FIG. 3
, the reservoir
10
is attached to a driveshaft housing or mid portion of the leg of an outboard motor.
Also shown in
FIG. 2
are the regulator
64
, the outlet
34
of the second pump
30
, the outlet
26
of the first pump
20
, and a vent
96
which allows fuel vapor to escape from the ullage above the level
72
of the liquid fuel within the cavity
12
of the reservoir
10
.
FIG. 3
shows a midsection
100
of an outboard motor with the reservoir
10
attached to it. Those skilled in the art of outboard motor design and manufacture are familiar with the overall structure of the midsection
100
, or driveshaft housing, and the details will not be described herein. The anti-cavitation plate
102
is shown for reference at the bottom portion of the midsection
100
. A driveshaft (not shown) extends downward in a vertical direction through the midsection
100
and connects the crankshaft of an engine located above the midsection
100
to a gear housing
105
and propeller shaft which are not shown in FIG.
3
. The propeller
107
and gear housing (
105
) are illustrated in
FIG. 3
to show that the gear housing
105
is supported at the bottom portion of the midsection
100
, or driveshaft housing, and the gear housing
105
, in turn, supports a propeller shaft to which a propeller
107
is attached. The internal portion of the midsection
100
also provides a conduit
110
for the downward transmission of exhaust gases from the engine to an outlet located in the gear housing
105
.
With continued reference to
FIG. 3
, it can be appreciated that the location of the reservoir
10
on the midsection
100
at the position shown in
FIG. 3
causes the reservoir
10
to be immersed in water when the propulsion system is not actively driving a marine vessel on plane. When the marine propulsion system is inactive and the marine vessel settles to a resting position on the water, the reservoir
10
is lowered to a position that disposes it at least partially under the surface of the body of water in which the marine vessel is operated. This serves to provide additional cooling to the liquid and vapors within the reservoir
10
and further prevent the vaporization of liquid fuel within the components of the fuel delivery system as a result of heat transferred to the fuel delivery system from the engine after water drains from the engine cooling system and heat begins to be conducted outwardly from the combustion chambers to surrounding components, including components of the fuel delivery system. This transfer of heat from the engine to the components of the fuel delivery system after the engine is turned off typically results in vaporization of the fuel and the situation referred to as “vapor lock”. By immersing the reservoir
10
in the cooler water of a body of water when the marine vessel is stationary, this deleterious situation is avoided.
With reference to
FIGS. 1-3
, it can be seen that the present invention provides a reservoir
10
in which a first pump
20
and a second pump
30
are disposed in thermal communication with liquid fuel stored within the reservoir
10
. Liquid fuel can be pumped from a fuel tank
22
into the reservoir
10
and from the cavity
12
of the reservoir
10
to an internal combustion engine of the marine propulsion system. Both the first and second pumps,
20
and
30
, are disposed in thermal communication within the liquid fuel in order to moderate the temperature of the two pumps. In addition, when mounted on the driveshaft housing
100
, or midsection, a further benefit can be achieved when the reservoir
10
is at least partially submerged in the water in which the marine vessel is operated when the marine propulsion unit is not actively propelling the marine vessel on plane. When the marine vessel stops its forward movement, it settles to a position that disposes the reservoir
10
in thermal communication with lake water or sea water and this action further reduces the temperature of the reservoir
10
and its contents, which include the liquid fuel
16
, the first and second pumps, and the various conduits through which liquid fuel is pumped by the fuel system. The present invention provides advantages which include the compactness of its design, which reduces the volumetric space required for the components, and the additional temperature moderation provided to the components of the fuel system which reduces the likelihood that “vapor lock” will occur. When the marine vessel is not operating on plane, the reservoir
10
is naturally lowered to a position illustrated in
FIG. 3
with respect to dashed line
110
which approximates the level of the body of water in which the marine vessel is operated.
Although the present invention has been described with particular detail to illustrate several embodiments of the present invention, it should be understood that alternate embodiments are also within its scope.
Claims
- 1. A fuel system for a marine propulsion system, comprising:a reservoir having a cavity for containing liquid fuel for use by said marine propulsion system; a first pump for drawing fuel from a fuel tank and pumping said fuel at a first pressure magnitude into said cavity, said first pump being disposed within said cavity, said reservoir and said first pump each being spaced apart from said fuel tank, said fuel tank being connected in fluid communication with said first pump by a fluid conduit; and a second pump for drawing said fuel from said cavity and pumping said fuel at a second pressure magnitude to an engine of said marine propulsion system, said second pump being disposed within said cavity, said first and second pumps being disposed in thermal communication with said fuel when said fuel is within said cavity.
- 2. The fuel system of claim 1, further comprising:a fuel filter connected in fluid communication between said fuel tank and said first pump.
- 3. The fuel system of claim 2, wherein:said fuel filter is a water separating fuel filter.
- 4. The fuel system of claim 1, further comprising:a fuel rail connected in fluid communication with an outlet of said second pump, said fuel rail being connected in fluid communication with a plurality of fuel injectors.
- 5. The fuel system of claim 4, further comprising:a fuel return line connected in fluid communication between an outlet of said fuel rail and said reservoir.
- 6. The fuel system of claim 5, further comprising:a pressure regulator connected between said outlet of said fuel rail and said reservoir to maintain a preselected pressure within said fuel rail.
- 7. The fuel system of claim 6, wherein:said pressure regulator is connectable in fluid communication with an air intake manifold of said marine propulsion system and said preselected pressure is a preselected differential pressure magnitude above an air pressure within said air intake manifold.
- 8. The fuel system of claim 1, further comprising:a fuel level sensor disposed within said reservoir to detect a fuel level within said reservoir.
- 9. The fuel system of claim 8, further comprising:an engine control module connected in signal communication with said first pump and in signal communication with said fuel level sensor.
- 10. The fuel system of claim 1, wherein:said first pressure magnitude is less than said second pressure magnitude.
- 11. The fuel system of claim 1, wherein:said marine propulsion system is an outboard motor.
- 12. A fuel system for a marine propulsion system, comprising:a reservoir having a cavity for containing liquid fuel for use by said marine propulsion system; a first pump for drawing fuel from a fuel tank and pumping said fuel at a first pressure magnitude into said cavity, said first pump being disposed within said cavity, said reservoir and said first pump each being spaced apart from said fuel tank, said fuel tank being connected in fluid communication with said first pump by a fluid conduit; a second pump for drawing said fuel from said cavity and pumping said fuel at a second pressure magnitude to an engine of said marine propulsion system, said second pump being disposed within said cavity, said first and second pumps being disposed in thermal communication with said fuel when said fuel is within said cavity; a fuel rail connected in fluid communication with an outlet of said second pump, said fuel rail being connected in fluid communication with a plurality of fuel injectors; and a fuel level sensor disposed within said reservoir to detect a fuel level within said reservoir.
- 13. The fuel system of claim 12, further comprising:a fuel filter connected in fluid communication between said fuel tank and said first pump.
- 14. The fuel system of claim 13, further comprising:a fuel return line connected in fluid communication between an outlet of said fuel rail and said reservoir; and a pressure regulator connected between said outlet of said fuel rail and said reservoir to maintain a preselected pressure within said fuel rail, said pressure regulator being connectable in fluid communication with an air intake manifold of said marine propulsion system and said preselected pressure being a preselected differential pressure magnitude above an air pressure within said air intake manifold, said first pressure magnitude being less than said second pressure magnitude.
- 15. The fuel system of claim 14, further comprising:an engine control module connected in signal communication with said first pump and in signal communication with said fuel level sensor.
- 16. A fuel system for a marine propulsion system, comprising:a reservoir having a cavity for containing liquid fuel for use by said marine propulsion system, said reservoir being at least partially submerged in water when a propeller of said marine propulsion system is not operative; a first pump for drawing fuel from a fuel tank and pumping said fuel at a first pressure magnitude into said cavity, said first pump being disposed within said cavity, said reservoir and said first pump each being spaced apart from said fuel tank, said fuel tank being connected in fluid communication with said first pump by a fluid conduit; a second pump for drawing said fuel from said cavity and pumping said fuel at a second pressure magnitude to an engine of said marine propulsion system, said second pump being disposed within said cavity, said first and second pumps being disposed in thermal communication with said fuel when said fuel is within said cavity; a fuel rail connected in fluid communication with an outlet of said second pump, said fuel rail being connected in fluid communication with a plurality of fuel injectors; a fuel level sensor disposed within said reservoir to detect a fuel level within said reservoir; and a fuel return line connected in fluid communication between an outlet of said fuel rail and said reservoir; and a pressure regulator connected between said outlet of said fuel rail and said reservoir to maintain a preselected pressure within said fuel rail, said pressure regulator being connectable in fluid communication with an air intake manifold of said marine propulsion system and said preselected pressure being a preselected differential pressure magnitude above an air pressure within said air intake manifold, said first pressure magnitude being less than said second pressure magnitude.
- 17. The fuel system of claim 16, further comprising:a fuel filter connected in fluid communication between said fuel tank and said first pump; and an engine control module connected in signal communication with said first pump and in signal communication with said fuel level sensor.
- 18. A fuel system for a marine propulsion system, comprising:a reservoir having a cavity for containing liquid fuel for use by said marine propulsion system; a first pump for drawing fuel from a fuel tank and pumping said fuel at a first pressure magnitude into said cavity, said first pump being disposed within said cavity, said reservoir and said first pump each being spaced apart from said fuel tank, said fuel tank being connected in fluid communication with said first pump by a fluid conduit; a second pump for drawing said fuel from said cavity and pumping said fuel at a second pressure magnitude to an engine of said marine propulsion system, said second pump being disposed within said cavity, said first and second pumps being disposed in thermal communication with said fuel when said fuel is within said cavity; a fuel level sensor disposed within said reservoir to detect a fuel level within said reservoir; and an engine control module connected in signal communication with said first pump and in signal communication with said fuel level sensor.
- 19. A fuel system for a marine propulsion system, comprising:a reservoir having a cavity for containing liquid fuel for use by said marine propulsion system; a first pump for drawing fuel from a fuel tank and pumping said fuel at a first pressure magnitude into said cavity, said first pump being disposed within said cavity, said reservoir and said first pump each being spaced apart from said fuel tank, said fuel tank being connected in fluid communication with said first pump by a fluid conduit; and a second pump for drawing said fuel from said cavity and pumping said fuel at a second pressure magnitude to an engine of said marine propulsion system, said second pump being disposed within said cavity, said first and second pumps being disposed in thermal communication with said fuel when said fuel is within said cavity, said first pressure magnitude being less than said second pressure magnitude.
- 20. A fuel system for a marine propulsion system, comprising:a reservoir having a cavity for containing liquid fuel for use by said marine propulsion system; a first pump for drawing fuel from a fuel tank and pumping said fuel at a first pressure magnitude into said cavity, said first pump being disposed within said cavity, said reservoir and saif first pump each being spaced apart from said fuel tank, said fuel tank being connected in fluid communication with said first pump by a fluid conduit; and a second pump for drawing said fuel from said cavity and pumping said fuel at a second pressure magnitude to an engine of said marine propulsion system, said second pump being disposed within said cavity, said first and second pumps being disposed in thermal communication with said fuel when said fuel is within said cavity, said marine propulsion system being an outboard motor.
US Referenced Citations (31)