Patent Description:
Traditional fuel storage and delivery systems that include saddle fuel tanks utilize fuel transfer systems that apply various methods to transfer fuel between chambers of the tank as described in <CIT>. Some fuel transfer systems include motor driven pumps located in a primary chamber that supply high pressure fuel to a separate jet pump, also located in the primary chamber, to draw fuel from an auxiliary chamber. The location of the jet pump in the primary chamber, and the design of the jet pump itself can lead to less than optimal fuel transfer performance. For example, traditional jet pumps include bodies made of plastic and insert with calibrated orifices made of brass. Such a material configuration can lead to poor fit conditions between the body and insert, and poor creep resistance when exposed to harsh fuel and temperature environments.

Jet pumps for fuel transfers systems or other automotive uses are e.g. disclosed in <CIT>, <CIT>, <CIT> and <CIT>.

Accordingly, it is desirable to optimize the configuration and placement of jet pumps in a fuel transfer system along with optimizing jet pump designs.

In accordance with a first embodiment of the present disclosure, a fuel jet pump assembly includes a body and a tubular insert. The body defines a mixing passage, a low pressure passage, and a cavity in communication with one another at an intersection. The body further includes a stop face. The tubular insert includes opposite first and second end portions and a mid-portion. The mid-portion defines a high pressure passage extending along a centerline, extending axially between the first and second end portions, and disposed in the cavity. The first end portion is located at the intersection, and defines a calibrated orifice in fluid communication with the low pressure passage, the high pressure passage and the mixing passage. The second end portion includes an enlarged head projecting radially outward from the mid-portion, and defines an inlet port in fluid communication with the high pressure passage. The enlarged head includes a stop surface in axial contact with the stop face. The mid-portion includes a circumferentially continuous barb in biased radial contact with a circumferentially continuous seat of the body that defines at least in-part the cavity.

Within the fuel jet pump assembly, the body and the tubular insert may be made of plastic.

Also within the fuel jet pump assembly, the stop face and the stop surface may be annular in shape and centered to the centerline.

The calibrated orifice may be centered to the centerline.

The tubular insert may be interchangeable.

The high pressure passage may flow fuel from the inlet port and through the calibrated orifice, the low pressure passage may flow fuel into the intersection, and the mixing passage may flow fuel emitted from the intersection.

The mixing passage may extend along the centerline, and may include a venturi segment extending axially.

The mixing passage may include a tubular segment communicating axially between the intersection and the venturi segment.

According to another, non-limiting, embodiment of the present disclosure, a fuel system comprises a partitioned fuel tank that defines a first chamber and a second chamber. The fuel system includes a fuel pump assembly, a fuel jet pump assembly, a high pressure conduit, and a low pressure conduit. The fuel pump assembly is disposed in the first chamber, and includes a motorized fuel pump. The fuel jet pump assembly is disposed in the second chamber, so that the low pressure passage is arranged to draw fuel from the second chamber and the mixing passage is arranged to receive and mix fuel flowing from the low and high pressure passages. The high pressure conduit extends between the first and second chambers, and is in fluid communication between an outlet of the fuel pump and the high pressure passage. The low pressure conduit extends between the first and second chambers, and is in fluid communication between the mixing passage and the first chamber.

Within the fuel system, the fuel jet pump device may define a calibrated orifice and an intersection, the calibrated orifice being in fluid communication between the high pressure passage and the intersection, and the intersection adapted to receive fuel from the low pressure passage and the calibrated orifice and expel fuel into the mixing passage.

The fuel jet pump device may include a body that defines the mixing passage, the low pressure passage, the intersection, and a cavity in communication with the intersection, and may include a tubular insert disposed in the cavity and seated to the body, the tubular insert may define the calibrated orifice and the high pressure passage.

The body may define a venturi as part of the mixing passage.

Also in the fuel system, the cavity and the high pressure passage may be substantially aligned axially and co-extend axially along a centerline, and the body may include a stop face facing axially and in contact with an axially opposing stop surface of the tubular insert.

The tubular insert of the fuel system may include opposite first and second end portions and a mid-portion extending axially between the first and second end portions, the mid-portion defining the high pressure passage, the first end portion being located at the intersection and defining the calibrated orifice, the second end portion including an enlarged head projecting radially outward from the mid-portion and defining an inlet port in fluid communication with the high pressure passage, the enlarged head including the stop surface.

The body and the tubular insert may be made of plastic.

The stop face and the stop surface may be annular in shape and centered about the centerline.

The fuel pump assembly may include a structure that defines a reservoir, and the low pressure conduit may be adapted to flow fuel from the second chamber and into the reservoir.

The fuel pump may be adapted to draw fuel from the reservoir.

The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

Referring now to the Figures, where the invention will be described with reference to specific embodiments, without limiting same, a fuel storage and delivery system <NUM> is illustrated in <FIG>, and may be utilized to store fuel <NUM> in a transport vehicle (not shown) and deliver the fuel to a combustion engine <NUM> of the vehicle. The fuel storage and delivery system <NUM> includes a partitioned tank <NUM> (e.g., saddle tank) for storing the fuel <NUM>, and a fuel transfer system <NUM> adapted to deliver the fuel <NUM> to the combustion engine <NUM>.

The partitioned tank <NUM> may include boundaries that define a first chamber <NUM> and a second chamber <NUM> separated by a partition <NUM> of the tank. In one embodiment, the first chamber <NUM> may be a primary chamber and the second chamber <NUM> may be an auxiliary chamber in direct fluid communication with the primary chamber above the partition <NUM>. The fuel <NUM> may be stored in the tank <NUM> at substantially atmospheric pressure. In another embodiment, the partitioned tank <NUM> may be two separate tanks, or compartments, in fluid communication with one another via at least one conduit (not shown).

Referring to <FIG> and <FIG>, the fuel transfer system <NUM> of the fuel storage and delivery system <NUM> may include a fuel pump assembly <NUM>, a fuel jet pump device <NUM>, a high pressure conduit <NUM>, and a relatively low pressure conduit <NUM>. The fuel pump assembly <NUM> may be located in the first, or primary, chamber <NUM>, and is constructed to draw fuel from both chambers <NUM>, <NUM> and deliver pressurized fuel to the combustion engine <NUM> via a supply conduit <NUM>.

The fuel pump assembly <NUM> of the fuel transfer system <NUM> may include a support structure <NUM> that may generally include a fuel reservoir <NUM>, at least one fuel pump (i.e., two illustrated in <FIG> as <NUM>, <NUM>), at least one check valve (i.e. two illustrated in <FIG> as <NUM>, <NUM>), a pressure relief valve <NUM>, an anti-siphon valve <NUM>, a first, or primary, primary jet pump device <NUM>, a strainer <NUM>, an umbrella valve <NUM>.

The support structure <NUM> of the fuel pump assembly <NUM> may generally include a lid <NUM>, support stanchions or members <NUM> (i.e., two illustrated in <FIG>), and a housing <NUM> (see <FIG>). The lid <NUM> is adapted to sealably cover an opening <NUM> communicating through a wall <NUM> (e.g., upper wall) of the tank <NUM>. The stanchions <NUM> extend between, and are connected to, the housing <NUM> and the lid <NUM>. In one embodiment, the stanchions <NUM> are elongated and extend substantially vertically, to generally place the housing <NUM> proximate to a bottom wall <NUM> of the tank <NUM> that defines in-part the first chamber <NUM>. The housing <NUM> is constructed to generally encapsulate and/or support the fuel pumps <NUM>,<NUM>, the check valve <NUM>, <NUM>, the pressure relief valve <NUM>, the anti-siphon valve <NUM>, the primary jet pump device <NUM>, the strainer <NUM>, the umbrella valve <NUM>, and the fuel reservoir <NUM>. In one embodiment, the reservoir <NUM> may be a unitary part of the housing <NUM>.

The fuel pumps <NUM>, <NUM> are of the mechanically driven type, and thus may include electric motors (not shown) to drive the pumps. The first pump <NUM> may be adapted to supply pressurized fuel to the supply conduit <NUM>, and the primary jet pump device <NUM>. The high pressure fuel flowing to the primary jet pump device <NUM> facilitates the drawing of low pressure fuel by the primary jet pump device <NUM> from the first chamber <NUM>. The low pressure fuel is then mixed with the incoming high pressure fuel from the first pump <NUM>, and the primary jet pump device <NUM> then expels the mixed fuel at a low pressure into the reservoir <NUM>.

The second pump <NUM> is adapted to supply pressurized fuel to the supply conduit <NUM> and the fuel jet pump device <NUM>. The fuel jet pump device <NUM> is constructed to draw low pressure fuel from the second chamber <NUM>, mix the low pressure fuel with the incoming high pressure fuel from the second pump <NUM>, and expel the mixed fuel at a low pressure into the reservoir <NUM>. In one embodiment, the mixed fuel from either jet pump devices <NUM>, <NUM> may be at about atmospheric pressure.

Each fuel pump <NUM>, <NUM> includes respective outlets <NUM>, <NUM> (i.e., outlet conduits) and respective inlets <NUM>, <NUM> (i.e., inlet conduits). Each outlet <NUM>, <NUM> communicates directly with the supply conduit <NUM>, and each inlet <NUM>, <NUM> is in fluid communication with the strainer <NUM>. The strainer <NUM> is constructed to draw fuel from the reservoir <NUM>, and thus provide filtered fuel to both pumps <NUM>, <NUM>.

The check valves <NUM>, <NUM> are located at respective outlets <NUM>, <NUM> of each respective pump <NUM>, <NUM>, and are adapted to prevent the backflow of fuel through the pumps. The pressure relief valve <NUM> is in fluid communication with the supply conduit <NUM>, and is adapted to expel fuel from the supply conduit <NUM> and, in one example, back into the reservoir <NUM> upon overpressure conditions. The umbrella valve <NUM> communicates through a bottom portion of the reservoir <NUM>, and facilitates level control of fuel within the reservoir <NUM>.

The primary jet pump device <NUM> receives high pressure fuel from pump <NUM> via a high pressure conduit <NUM> that extends between the outlet <NUM> (i.e., upstream of the check valve <NUM>) and the primary jet pump device <NUM>. The anti-siphon valve <NUM> may be located in the high pressure conduit <NUM> (i.e., interposes), and is adapted to prevent siphoning of fuel from the first chamber <NUM>, back-flowing through the primary jet pump device <NUM>, and back-flowing through the pump <NUM> when the pump <NUM> is idle.

Referring to <FIG> and <FIG>, the fuel jet pump device <NUM> includes a body <NUM> that may be a unitary body, and an insert <NUM> that may be tubular and interchangeable. The body <NUM> defines a mixing passage <NUM>, a cavity <NUM>, an intersection <NUM>, and a low pressure passage <NUM>. The mixing passage <NUM>, the cavity <NUM>, and the low pressure passage <NUM> are in fluid communication with one another generally at the intersection <NUM>. In one embodiment, the mixing passage <NUM> and the cavity <NUM> extend along, and are centered to, a common centerline C. The intersection <NUM> is axially located between the mixing passage <NUM> and the cavity <NUM>.

Referring to <FIG>, when the fuel jet pump device <NUM> is assembled, the insert <NUM> is substantially located in the cavity <NUM>, and sealably seats against the body <NUM>. In one embodiment, the insert <NUM> includes opposite end portions <NUM>, <NUM> and a mid-portion <NUM> that extends axially between the end portions <NUM>, <NUM> and along the centerline C. The mid-portion <NUM> is tubular, and at least in-part, includes boundaries that define a high pressure passage <NUM>. The high pressure passage <NUM> is in fluid communication with the intersection <NUM> via a calibrated orifice <NUM> defined by the end portion <NUM> and centered to the centerline C. The end portion <NUM> may be in, or proximate to, the intersection <NUM>.

The end portion <NUM> may be, or may include, an enlarged head that projects radially outward from the mid-portion <NUM>. The end portion <NUM> may be annular in shape, and radially inwardly defines an inlet port <NUM> in fluid communication between the high pressure passage <NUM> and the high pressure conduit <NUM>. In one example, the end portion <NUM> carries a stop surface <NUM> that faces axially toward the end portion <NUM>, and may be annular in shape. The cavity <NUM> communicates through the body <NUM> at an end that carries a stop face <NUM> that faces axially, opposes the stop surface <NUM>, may be annular in shape, and may be centered to centerline C. When the fuel jet pump device <NUM> is assembled, the stop surface <NUM> is in contact with the stop face <NUM>, which facilitates placement (i.e., axial indexing) of the calibration orifice <NUM> in the intersection <NUM>.

The mid-portion <NUM> of the tubular insert <NUM> may include at least one circumferentially continuous barb <NUM> (i.e., two illustrate in <FIG>) spaced axially apart from one-another. Each barb <NUM> is in biased radial contact with a circumferentially continuous seat <NUM> of the body <NUM> that defines, at least in-part, the cavity <NUM>. As illustrated in <FIG>, the seat <NUM> faces radially inward, is cylindrical, and substantially defines the cavity <NUM>.

The mixing passage <NUM> defined by the body <NUM> may include a two tubular, or cylindrical, segments <NUM>, <NUM> extending along the centerline C, and axially spaced apart from one-another by a venturi segment <NUM>. The cylindrical segment <NUM> includes a diameter that is less than a diameter of cylindrical segment <NUM>, and communicates axially between the intersection <NUM> and the venturi segment <NUM>. The cylindrical segment <NUM> communicates through the body <NUM>, and between the venturi segment <NUM> and the low pressure conduit <NUM>.

The mixing passage <NUM> and the cavity <NUM> may be substantially aligned axially and co-extend axially along the centerline C. The low pressure passage <NUM> may be generally normal to the mixing passage <NUM>. In one embodiment, the body <NUM> and the insert <NUM> are made of the same material, and both may be made of plastic. The insert <NUM> may further be interchangeable with other inserts having varying sized orifices. The ideal insert <NUM> may then be chosen to meet specific fluid dynamics of any particular delivery system <NUM>.

It is contemplated and understood that the insert <NUM> may not generally be tubular, and instead may be disc-shaped with a centrally located orifice. In this example, an axially leading surface of the disc may contact an axial face of the body <NUM>. That is, the disc-like insert <NUM> may seat within a counter-bore in the body.

It is further contemplated and understood that design attributes of the fuel jet pump device <NUM> may be applied to the primary jet pump device <NUM>.

In operation of the fuel jet pump device <NUM>, high pressure fuel produced by the pump <NUM>, flows through the high pressure conduit <NUM>, axially through the high pressure passage <NUM>, through the calibration orifice <NUM>, and generally into the intersection <NUM> immediately adjacent to the segment <NUM> of the mixing passage <NUM>. The high pressure flow through the calibration orifice <NUM> causes the low pressure passage <NUM> to draw fuel from the second chamber <NUM>. This low pressure fuel flows through the low pressure passage <NUM>, through at least a portion of the intersection <NUM> and into the segment <NUM> of the mixing passage <NUM>. The high and low pressure fuel is then mixed and reduced in pressure as it flows through the segment <NUM>, through the venturi segment <NUM>, through the segment <NUM>, and into the low pressure conduit <NUM>. The low pressure conduit <NUM> may then deliver the fuel to the reservoir <NUM> in first chamber <NUM>.

Advantage and benefits of the present disclosure include: a reduction in the amount of critical high pressure assembly interfaces within the jet pump device, a flexible jet pump design that is easily adaptable for saddle tank application which traditionally demand high performance transfer systems, a self-centered plastic molded insert <NUM> with a calibrated orifice <NUM> and indexing features for proper position of the orifice, a reduced amount of components from more traditional designs, and a reduced likelihood of burrs and machined defects that more negatively impact system performance.

Claim 1:
A fuel jet pump assembly (<NUM>) comprising:
a body (<NUM>) defining a mixing passage (<NUM>), a low pressure passage (<NUM>), and a cavity (<NUM>) in communication with one another at an intersection (<NUM>), the body (<NUM>) including a stop face (<NUM>); and
a tubular insert (<NUM>) including opposite first and second end portions (<NUM>,<NUM>) and a mid-portion (<NUM>), the mid-portion (<NUM>) defining a high pressure passage (<NUM>) extending along a centerline, extending axially between the first and second end portions (<NUM>,<NUM>), and disposed in the cavity (<NUM>), the first end portion (<NUM>) located at the intersection (<NUM>) and defining a calibrated orifice (<NUM>) in fluid communication with the low pressure passage (<NUM>), the high pressure passage (<NUM>) and the mixing passage (<NUM>), the second end portion (<NUM>) including an enlarged head projecting radially outward from the mid-portion (<NUM>) and defining an inlet port (<NUM>) in fluid communication with the high pressure passage (<NUM>), the enlarged head including a stop surface (<NUM>) in axial contact with the stop face (<NUM>);
characterised in that the mid-portion (<NUM>) includes a circumferentially continuous barb (<NUM>) in biased radial contact with a circumferentially continuous seat (<NUM>) of the body (<NUM>) that defines at least in-part the cavity (<NUM>).