Jet pump assembly

A jet pump assembly includes a fuel supply conduit, a first jet pump integrally formed as a single piece with the fuel supply conduit and in fluid communication with the fuel supply conduit, a second jet pump integrally formed as a single piece with the fuel supply conduit and in fluid communication with the fuel supply conduit, and an inlet conduit integrally formed as a single piece with the second jet pump.

FIELD OF THE INVENTION

The present invention relates to vehicle fuel systems, and more particularly to vehicle fuel systems including jet pump assemblies.

BACKGROUND OF THE INVENTION

The use of bifurcated fuel tanks, also commonly referred to as saddle tanks, in conjunction with fuel delivery systems having a single fuel pump is known. In such systems, a reservoir surrounds the fuel pump and is constantly filled to ensure that a steady supply of fuel is available to the pump at all times. Normally, fuel is drawn into the fuel pump from the bifurcated tank portion housing the fuel pump, but if the fuel level is low or vehicle maneuvering is such that the fuel pump inlet cannot draw fuel, the fuel pump instantly draws fuel from the reservoir. A jet pump is typically used to draw fuel from the opposing bifurcated portion of the tank through a crossover line and into the reservoir. Fuel typically overflows the reservoir and excess fuel fills the bifurcated tank portion housing the fuel pump. This ensures that fuel is available to the fuel pump regardless of the level of fuel in either of the bifurcated tank portions.

SUMMARY OF THE INVENTION

The present invention provides, in one aspect, a jet pump assembly including a fuel supply conduit, a first jet pump integrally formed as a single piece with the fuel supply conduit and in fluid communication with the fuel supply conduit, a second jet pump integrally formed as a single piece with the fuel supply conduit and in fluid communication with the fuel supply conduit, and an inlet conduit integrally formed as a single piece with the second jet pump.

The present invention provides, in another aspect, a fuel pump module including a fuel reservoir and a separate jet pump assembly positioned in the fuel reservoir. The jet pump assembly includes a fuel supply conduit, a first jet pump integrally formed as a single piece with the fuel supply conduit and in fluid communication with the fuel supply conduit, a second jet pump integrally formed as a single piece with the fuel supply conduit and in fluid communication with the fuel supply conduit, and an inlet conduit integrally formed as a single piece with the second jet pump.

DETAILED DESCRIPTION

FIGS. 1-3illustrate a first construction of a jet pump assembly10positionable in a reservoir14of a fuel pump module16for an internal combustion engine. In addition to the reservoir14, other components of the fuel pump module16(e.g., a fuel pump18, one or more filters22, a check valve26, and a fuel pressure regulator30) are schematically illustrated inFIG. 3. The fuel pump module16is positioned on a primary side34of a bifurcated or saddle-style fuel tank38. As described in more detail below, the jet pump assembly10draws fuel from both the primary side34of the fuel tank and a secondary side42of the fuel tank38into the reservoir14to fill the reservoir14and substantially immerse the fuel pump18with fuel. This allows the fuel pump18to access a substantially continuous supply of fuel regardless of the level of fuel in the primary side34or the secondary side42of the fuel tank38. Such a saddle-style fuel tank38is described in more detail in U.S. Pat. No. 6,371,153, the entire content of which is incorporated herein by reference.

With reference toFIGS. 1 and 3, the jet pump assembly10includes a fuel supply conduit46and a first or primary jet pump50integrally formed as a single piece with the fuel supply conduit46and oriented substantially normal to the fuel supply conduit46. The primary jet pump50is in fluid communication with the fuel supply conduit46to receive pressurized fuel from the fuel supply conduit46during operation of the fuel pump18. With reference toFIG. 3, the fuel supply conduit46receives pressurized fuel directly from the output of the fuel pump18via a separate fuel supply conduit (not labeled). Specifically, the fuel pump module16also includes a throttle member54(e.g., an orifice) positioned upstream of the fuel supply conduit46to reduce the pressure of the pressurized fuel delivered to the fuel supply conduit46. For example, the throttle member54may reduce the pressure of the pressurized fuel delivered to the fuel supply conduit46from about 5 bars to about 1 bar. Alternatively, the throttle member54may be configured to reduce the pressure of the pressurized fuel delivered to the fuel supply conduit46by a different amount.

With reference toFIG. 4, the jet pump assembly10may be positioned within the fuel pump module such that the fuel supply conduit46receives “return” fuel from the fuel pressure regulator30to power the primary jet pump50. The fuel pump18is sized to deliver fuel to the engine at a maximum flow rate and pressure. The fuel pressure regulator30provides a regulated supply of fuel to the engine that is often less than the maximum flow rate and pressure that the fuel pump18is capable of providing. The fuel pressure regulator30, therefore, returns excess fuel that is not needed by the engine to the reservoir14to fill the reservoir14. More particularly, the excess or return fuel from the fuel pressure regulator30is used to power the primary jet pump50before being returned to the reservoir14.

With reference toFIG. 1, the jet pump assembly10also includes a base58integrally formed as a single piece with the fuel supply conduit46and the primary jet pump50. The base58defines an internal chamber60having an opening adjacent the bottom of the base58through which fuel is drawn in response to fuel being discharged through the primary jet pump50. The reservoir14includes a receptacle (not shown) sized to receive the base58therein. An interference fit between the receptacle and the base58of the jet pump assembly10may be employed to at least partially secure the jet pump assembly10to the reservoir14. Alternatively, any of a number of different fasteners or processes may be employed to secure the jet pump assembly10to the reservoir14(e.g., using screws, quick-connect structures, welding, adhesives, etc.).

With reference toFIG. 3, a one-way valve62(e.g., an umbrella-style valve) is coupled to the bottom of the reservoir14and is positioned within the internal chamber60of the base58. Such a valve62is described in more detail in U.S. Pat. No. 5,769,061, the entire content of which is incorporated herein by reference. As is discussed in more detail below, the discharge of fuel through the primary jet pump50creates a region of low pressure within the internal chamber60, thereby opening the one-way valve62to allow fuel in the primary side34of the fuel tank38to be drawn into the chamber60and subsequently mixed with the fuel discharged through the primary jet pump50. The mixed fuel is then discharged into the reservoir14to fill the reservoir14. However, shortly after de-activation of the fuel pump18, fuel stops flowing through the primary jet pump50, allowing the pressure exerted on each side of the one-way valve62to equalize which, in turn, allows the valve62to close. When the valve62is closed, fuel in the reservoir14is prevented from back-flowing through the primary jet pump50and siphoning to the primary side34of the fuel tank38.

With continued reference toFIG. 3, the primary jet pump50also includes a nozzle66positioned adjacent the internal chamber60of the base58and a mixing tube70positioned downstream of the nozzle66(seeFIGS. 1 and 2). As described above, discharge of fuel through the nozzle66creates a region of low pressure within the internal chamber60to open the one-way valve62and draw fuel from the primary side34of the fuel tank38into the chamber60, where the fuel is mixed with fuel discharged through the nozzle66in the mixing tube70. The mixed fuel is then discharged from the mixing tube70into the reservoir14.

With reference toFIGS. 1 and 3, the jet pump assembly10also includes a second or secondary jet pump74integrally formed as a single piece with the fuel supply conduit46. The secondary jet pump74is in fluid communication with the fuel supply conduit46to receive pressurized fuel from the fuel supply conduit46during operation of the fuel pump18. As shown inFIGS. 3 and 4, the primary and secondary jet pumps50,74are fluidly connected to the fuel supply conduit46in a parallel arrangement, such that the pressure of the fuel delivered to each of the primary and secondary jet pumps50,74is substantially similar. Alternatively, the throttle member54may be associated with only one of the primary and secondary jet pumps50,74such that one of the jet pumps50,74receives fuel at a higher pressure than the other. Further, an additional throttle member may be associated with one of the primary and secondary jet pumps50,74such that one of the jet pumps50,74receives fuel at a lower pressure than the other. The secondary jet pump74includes a nozzle78and a mixing tube82positioned downstream of the nozzle78.

With reference toFIGS. 1 and 2, the jet pump assembly10further includes an inlet conduit86integrally formed as a single piece with the secondary jet pump74and an anti-siphon valve90incorporated in the inlet conduit86. The inlet conduit86fluidly communicates the secondary jet pump74and the secondary side42of the bifurcated or saddle-style fuel tank38to allow the secondary jet pump74to draw fuel from the secondary side42of the fuel tank38. The inlet conduit86includes a plurality of barbs94arranged about its outer peripheral surface that facilitate securing a rubber or plastic “crossover” tube98to the inlet conduit86. Such a crossover tube98(shown schematically inFIGS. 3 and 4) extends from the inlet conduit86, over the hump of the bifurcated or saddle-style fuel tank38, and into the secondary side42of the fuel tank38.

With reference toFIGS. 1 and 2, the anti-siphon valve90includes a plurality of ribs102extending radially inwardly into the inlet conduit86. The ribs102are integrally formed as a single piece with the inlet conduit86. Although only two ribs102are illustrated inFIGS. 1 and 2, at least three ribs102extend radially inwardly into the inlet conduit86. In addition, the ribs102are arranged symmetrically (i.e., equi-angularly spaced from each other) about a central axis of the inlet conduit. Alternatively, the ribs102may be arranged asymmetrically about the central axis of the inlet conduit86, the purpose of which is discussed below. Each of the ribs102includes an inclined surface106toward the top of each of the ribs102, the purpose of which is also discussed below. Alternatively, each of the ribs102may include a rounded corner or a ninety-degree corner toward the top of each of the ribs102.

With continued reference toFIGS. 1 and 2, the anti-siphon valve90also includes an orifice110defined in the inlet conduit86. More particularly, the orifice110is defined within an annular insert114positioned in the inlet conduit86. The insert114may be a separate and distinct component from the inlet conduit86that is secured to the inlet conduit86during manufacture of the jet pump assembly10(e.g., by using an interference fit, welding, adhesives, etc.). Alternatively, the insert114may be integrally formed as a single piece with the inlet conduit86. The anti-siphon valve90further includes a ball118movable in the inlet conduit86between a first position, in which the ball118is seated against the top surfaces106of the ribs102, and a second position, in which the ball118is positioned adjacent the orifice110to block the flow of fuel through the orifice110. The ball118is buoyant in fuel, such that the ball118is floated to the second position to block fuel flow through the orifice110by stagnant fuel in the inlet conduit86. Alternatively, the ball118may not be buoyant in fuel, and a brief reverse flow of fuel through the inlet conduit86in response to deactivation of the fuel pump18may displace the ball118from being supported by the ribs102(seeFIG. 2) toward the insert114. After the ball118is seated against the insert114to block the orifice110(seeFIG. 1), the pressure of the stagnant fuel in the inlet conduit86may provide a sufficient force to maintain the ball118against the insert114to block the orifice110. As a further alternative, the anti-siphon valve90may include a resilient member (e.g., a spring) to bias the ball118toward the insert114to block the orifice110.

In operation of the fuel pump18and the jet pump assembly10, some of the pressurized fuel output by the fuel pump18is diverted toward the jet pump assembly10to power the jet pump assembly10and fill the reservoir14with fuel (seeFIG. 3). As discussed above, the pressure of the diverted fuel is reduced by the throttle member54prior to entering the fuel supply conduit46. The pressurized fuel in the fuel supply conduit46then feeds both the primary and secondary jet pumps50,74. As the pressurized fuel is discharged through the nozzle66of the primary jet pump50, a low-pressure region within the internal chamber60of the base58is created, thereby opening the one-way valve62to allow fuel from the primary side34of the fuel tank38to be drawn into the internal chamber60. Fuel drawn into the internal chamber60of the base58is mixed with the fuel discharged through the nozzle66in the mixing tube70and discharged into the reservoir14to fill the reservoir14(seeFIG. 2). While this occurs, pressurized fuel discharged through the nozzle78of the secondary jet pump74creates a low-pressure region within the inlet conduit86, thereby opening the anti-siphon valve90to allow fuel from the secondary side42of the fuel tank38to be drawn into the inlet conduit86(via the crossover tube98), where it is mixed with fuel discharged through the nozzle78in the mixing tube82and discharged into the reservoir14to fill the reservoir14.

More particularly, with reference toFIG. 2, the anti-siphon valve90is opened when the ball118is moved away from the insert114and held against the top surfaces106of the ribs102by the low-pressure region created in the inlet conduit86and the fuel flow through the inlet conduit86in the direction indicated by the arrows inFIG. 2. Because the ribs102are spaced from each other about the central axis of the inlet conduit86, fuel flow through the inlet conduit86may occur around the ball118and through the gaps between adjacent ribs102. Such fuel flow around the ball118would also cause the ball118to be seated or held against the top surfaces106of the ribs102in the middle of the inlet conduit86(i.e., the center of the ball118would be aligned with the central axis of the inlet conduit86). Alternatively, in a configuration of the jet pump assembly10in which the ribs102are asymmetrically positioned about the central axis of the inlet conduit86(i.e., when the spacing between adjacent ribs102is unequal), the fuel flow around the ball118may cause the ball118to wedge between adjacent ribs102at a location offset from the middle of the inlet conduit86, such that the center of the ball118would be misaligned with the central axis of the inlet conduit86. This asymmetrical arrangement of the ribs102may decrease the amount of flutter experienced by the ball118during operation of the jet pump assembly10.

With reference toFIG. 4, operation of the jet pump assembly10is substantially similar as that described above with respect toFIG. 3, except the jet pump assembly10is powered by return fuel from the fuel pressure regulator30rather than receiving fuel directly from the output of the fuel pump18. The return fuel provided by the fuel pressure regulator30has a reduced pressure compared to that of the fuel supplied to the engine, such that a throttle member (e.g., throttle member54) is not required upstream of the fuel supply conduit46.

FIGS. 5-7illustrate a second construction of a jet pump assembly122positionable in a reservoir14aof a fuel pump module16a, with like components having like reference numerals with the letter “a.” The jet pump assembly122includes a pressure relief valve126in fluid communication with the fuel supply conduit46ato selectively allow pressurized fuel in the fuel supply conduit46ato be discharged directly into the reservoir14awhile bypassing the primary and secondary jet pumps50a,74a. The pressure relief valve126includes a bypass conduit130integrally formed as a single piece with the fuel supply conduit46a, a seal member or poppet134movable between a first position adjacent an outlet of the bypass conduit130to block fuel flow through the outlet, and a second position spaced from the outlet, a retainer138coupled to the bypass conduit130, and a resilient member (e.g., a compression spring142) positioned between the poppet134and the retainer138to bias the poppet134toward the first position adjacent the outlet of the bypass conduit130. The retainer138includes a plurality of apertures146through which fuel is discharged from the outlet of the bypass conduit130and into the reservoir14. Alternatively, the retainer138may only include a single aperture146through which fuel is discharged from the outlet of the bypass conduit130and into the reservoir14. The retainer138may be coupled to the bypass conduit130in any of a number of different ways (e.g., by using fasteners, quick-connect structures, welding, using adhesives, a threaded engagement, etc.). Alternatively, the retainer138may be integrally formed with the bypass conduit130as a single piece, and the poppet134and/or spring142may be subsequently positioned in their respective locations shown inFIG. 5.

With reference toFIG. 6, the jet pump assembly122is operable in a similar manner as the jet pump assembly10inFIG. 3. Likewise, with reference toFIG. 7, the jet pump assembly122is operable in a similar manner as the jet pump assembly10inFIG. 4. However, should the pressure of the fuel upstream of the nozzles66a,78ain the respective primary and secondary jet pumps50a,74asuddenly increase beyond a predetermined amount, the pressurized fuel in the fuel supply conduit46amay unseat the poppet134from the outlet of the bypass conduit130, against the bias of the spring142, to allow some of the pressurized fuel in the fuel supply conduit46ato be discharged directly to the reservoir14a, thereby bypassing the primary and secondary jet pumps50a,74a. When the pressure of the fuel in the fuel supply conduit46adecreases below the predetermined amount, the spring142re-seats the poppet134against the outlet of the bypass conduit130to stop the discharge of fuel from the bypass conduit130.

FIG. 8illustrates a third construction of a jet pump assembly150positionable in a reservoir154which, in turn, is positioned in a fuel tank158(schematically illustrated inFIG. 9). The fuel system arrangement shown inFIG. 9is illustrative of a diesel fuel system which includes a lift pump162positioned outside of the fuel tank158. Generally, the lift pump162draws diesel fuel from the reservoir154and pumps the fuel toward the engine, through one or more fuel rails (not shown), and through a fuel pressure regulator (not shown). Unused fuel is discharged from the fuel pressure regulator and returned to the reservoir154to power the jet pump assembly150, which draws fuel from the fuel tank158to fill the reservoir154. Alternatively, the jet pump assembly150may be employed in a gasoline fuel system (e.g., the fuel system shown inFIGS. 3,4,6, and7) rather than a diesel fuel system.

With reference toFIG. 8, the jet pump assembly150includes a fuel supply conduit166and a jet pump170integrally formed as a single piece with the fuel supply conduit166and oriented substantially normal to the fuel supply conduit166. The jet pump170is in fluid communication with the fuel supply conduit166to receive pressurized fuel from the fuel supply conduit166during operation of the lift pump162. The pressurized fuel returning from the engine (i.e., the fuel downstream of the fuel pressure regulator) is at a lower pressure than the fuel consumed by the engine. As such, a throttle member (e.g., throttle members54,54ainFIGS. 3 and 6, respectively) upstream of the jet pump assembly150is not necessary. However, such a throttle member may be utilized to further reduce the pressure of the fuel delivered to the jet pump assembly150.

With reference toFIG. 8, the jet pump assembly150also includes a base174integrally formed as a single piece with the fuel supply conduit166and the jet pump170. The base174defines an internal chamber178having an opening182adjacent the bottom of the base174through which fuel is drawn in response to fuel being discharged through the jet pump170. The reservoir154includes a receptacle (not shown) sized to receive the base174therein. An interference fit between the receptacle and the base174may be employed to at least partially secure the jet pump assembly150to the reservoir154. Alternatively, any of a number of different fasteners or processes may be employed to secure the jet pump assembly150to the reservoir154. (e.g., using screws, quick-connect structures, welding, adhesives, etc.).

With reference toFIG. 9, a one-way valve186(e.g., an umbrella-style valve) is coupled to the bottom of the reservoir154and is positioned within the chamber178of the base174. Such a valve186is described in more detail in U.S. Pat. No. 5,769,061, the entire content of which is incorporated herein by reference. As is discussed in more detail below, the discharge of fuel through the jet pump170creates a region of low pressure within the chamber178, thereby opening the one-way valve186to allow fuel in the fuel tank158to be drawn into the chamber178and subsequently mixed with the fuel discharged through the jet pump170. The mixed fuel is then discharged into the reservoir154to fill the reservoir154. However, shortly after deactivation of the lift pump162, fuel stops flowing through the jet pump170, allowing the pressure exerted on each side of the one-way valve186to equalize which, in turn, allows the valve186to close. When the valve186is closed, fuel in the reservoir154is prevented from back-flowing through the jet pump170and siphoning to the fuel tank158.

With reference toFIG. 8, the jet pump170includes an orifice190positioned adjacent the chamber178and a mixing tube194positioned downstream of the orifice190. Unlike the jet pump assemblies10,122inFIGS. 1-7, the passageway in the jet pump170between the fuel supply conduit166and the orifice190does not include a converging section (i.e., a “converging nozzle”) to increase the flow rate of fuel as it passes through the jet pump170. Rather, the passageway in the jet pump170between the fuel supply conduit166and the orifice190is substantially straight. Alternatively, the passageway in the jet pump170between the fuel supply conduit166and the orifice190may include a converging nozzle section to increase the flow rate of fuel through the jet pump170. As described above, discharge of fuel through the orifice190creates a region of low pressure within the chamber178to open the one-way valve186, thereby allowing fuel from the fuel tank158to be drawn into the chamber178, where the fuel is mixed with fuel discharged through the orifice190. The mixed fuel is then discharged from the mixing tube194into the reservoir154. The jet pump assembly150may optionally include a plug (e.g., a ball bearing196) positioned within an aperture197formed in an outer wall of the jet pump170while molding the fuel supply conduit166, the base174, and the jet pump170as a single piece. Specifically, the aperture197may be formed by a slide used in an injection molding process to mold the passageway in the jet pump170between the fuel supply conduit166and the orifice190, and the orifice190itself. As such, insertion of the ball bearing196into the aperture197(via an interference fit, for example) effectively blocks the aperture197to substantially prevent fuel flow through the aperture197. Because the ball bearing196is a separate and distinct component from the fuel supply conduit166, the base174, and the jet pump170, the jet pump170is manufactured as a multi-piece or two-piece jet pump170. It should also be understood that the jet pump assemblies10,122ofFIGS. 1 and 5may be manufactured in a similar manner to include one or more ball bearings for sealing or blocking apertures formed by slides used in an injection molding process to mold the nozzles66,78,66a,78a.

With continued reference toFIG. 8, the jet pump assembly150also includes an anti-siphon valve198incorporated in the fuel supply conduit166. The anti-siphon valve198includes a plurality of ribs202extending radially inwardly into the fuel supply conduit166. The ribs202are integrally formed as a single piece with the fuel supply conduit166. Although only two ribs202are visible inFIG. 8, at least three ribs202extend radially inwardly into the fuel supply conduit166. In addition, the ribs202are arranged symmetrically (i.e., equi-angularly spaced from each other) about a central axis of the fuel supply conduit166. Alternatively, the ribs202may be arranged asymmetrically about the central axis of the fuel supply conduit166, the purpose of which is discussed below. Each of the ribs202includes an inclined corner surface206, the purpose of which is also discussed below. Alternatively, each of the ribs202may include a rounded corner or a ninety-degree corner toward the top of each rib202.

With continued reference toFIG. 8, the anti-siphon valve198also includes an orifice210defined in the fuel supply conduit166. More particularly, the orifice210is defined by an adapter214coupled to the fuel supply conduit166. As shown inFIG. 8, the adapter214is a separate and distinct component from the fuel supply conduit166that is secured to the fuel supply conduit166during manufacture of the jet pump assembly150(e.g., by using an interference fit, welding, adhesives, etc.). Alternatively, the adapter214may be integrally formed as a single piece with the fuel supply conduit166.

The anti-siphon valve198further includes a ball218movable in the fuel supply conduit166between a first position, in which the ball218is seated against the inclined corner surfaces206of the ribs202, and a second position, in which the ball218is positioned adjacent the orifice210to block the flow of fuel through the orifice210. The ball218is buoyant in fuel, such that the ball218is floated to the second position by stagnant fuel in the fuel supply conduit166(i.e., when the lift pump162is deactivated) to block fuel flow through the orifice210. Alternatively, the ball218may not be buoyant in fuel, and a brief reverse flow of fuel through the fuel supply conduit166may displace the ball218from its position shown inFIG. 8supported by the ribs202toward the adapter214. After the ball218is seated against the adapter214to block the orifice210, the pressure of the stagnant fuel in the fuel supply conduit166may provide a sufficient force to maintain the ball218against the adapter214to block the orifice210. As a further alternative, the anti-siphon valve198may include a resilient member (e.g., a spring) to bias the ball218toward the insert adapter214to block the orifice210.

With continued reference toFIG. 8, the adapter214includes a plurality of barbs222arranged about its outer peripheral surface that facilitate securing a rubber or plastic tube226(schematically illustrated inFIG. 9) to the adapter214which supplies the jet pump assembly150with return fuel from the engine. The adapter214further includes a mount230having a receptacle234configured and sized to receive a post (not shown) upstanding from a bottom wall of the reservoir154. The mount230is fixed to the post (e.g., by welding, using adhesives, etc.), thereby securing the fuel supply conduit166, the base174, and the jet pump170between the adapter214and the bottom wall of the reservoir154. Alternatively, the base174may be fixed to the reservoir154(e.g., by welding, using adhesives, etc.) to directly secure the jet pump assembly150to the reservoir154.

In operation of the lift pump162and the jet pump assembly150, the return fuel from the engine is used to power the jet pump assembly150to fill the reservoir154with fuel (seeFIG. 9). As discussed above, the pressure of the return fuel is reduced by the fuel pressure regulator on the engine prior to entering the fuel supply conduit166. The return fuel flow from the engine opens the anti-siphon valve198by displacing the ball218away from the orifice210and holding or maintaining the ball218against the inclined corner surfaces206of the ribs202. Because the ribs202are spaced from each other about the central axis of the fuel supply conduit166, fuel flow through the fuel supply conduit166may occur around the ball218and through the gaps between adjacent ribs202. Such fuel flow around the ball218would also cause the ball218to be seated or held against the inclined corner surfaces206of the ribs202in the middle of the fuel supply conduit166(i.e., the center of the ball218would be aligned with the central axis of the fuel supply conduit166). Alternatively, in a configuration of the jet pump assembly150in which the ribs202are asymmetrically positioned about the central axis of the fuel supply conduit166(i.e., when the spacing between adjacent ribs202is unequal), the fuel flow around the ball218may cause the ball218to wedge between adjacent ribs202at a location offset from the middle of the inlet conduit166, such that the center of the ball218would be misaligned with the central axis of the fuel supply conduit166. This asymmetrical arrangement of the ribs202may decrease the amount of flutter experienced by the ball218during operation of the jet pump assembly150.

After the pressurized fuel passes the anti-siphon valve198, the pressurized fuel in the fuel supply conduit166is discharged through the orifice190of the jet pump170. A low-pressure region within the chamber178of the base174is created, thereby opening the one-way valve186to allow fuel from the fuel tank158to be drawn into the chamber178where it is mixed with the fuel discharged through the orifice190. The mixed fuel is then discharged through the mixing tube194and into the reservoir154to fill the reservoir154. Shortly after the lift pump162is deactivated, the fuel flow through the fuel supply conduit166is stopped, thereby allowing the ball218to float upwardly toward the adapter214to block the orifice210to prevent fuel stored in the reservoir154from siphoning out of the fuel tank158via the jet pump assembly150. Should the ball218not be buoyant in fuel, a brief reverse flow of fuel through the fuel supply conduit166may displace the ball218from its position shown inFIG. 8supported by the ribs202toward the adapter214. After the ball218is seated against the adapter214to block the orifice210, the pressure of the stagnant fuel in the fuel supply conduit166would provide a sufficient force to maintain the ball218against the adapter214to block the orifice210and prevent fuel stored in the reservoir154from siphoning out of the fuel tank158via the jet pump assembly150.

With reference toFIG. 10, a fourth construction of a jet pump assembly238is schematically illustrated. Like components are labeled with like reference numerals, with the letter “b.” Like the fuel system arrangement shown inFIG. 9, the fuel system arrangement ofFIG. 10is illustrative of a diesel fuel system including a lift pump162bpositioned outside a fuel tank242. However, the fuel tank242schematically illustrated inFIG. 10is a bifurcated or saddle-style fuel tank242similar to the fuel tanks38,38adiscussed above. As a result, the jet pump assembly238includes a secondary jet pump246integrally formed as a single piece with the fuel supply conduit166b, an inlet conduit250integrally formed as a single piece with the secondary jet pump246, and an anti-siphon valve254incorporated in the inlet conduit250. The secondary jet pump246, the inlet conduit250, and the anti-siphon valve254are structurally similar to the secondary jet pump74,74a, the inlet conduit86,86a, and the anti-siphon valve90,90aof the jet pump assemblies10,122ofFIGS. 1-7, and will not be described again in detail. Likewise, the manner of operation of the secondary jet pump246and the anti-siphon valve254is similar to the manner of operation described above with respect to the secondary jet pump74,74aand anti-siphon valve90,90aof the jet pump assemblies10,122ofFIGS. 1-7, and will not be described again in detail.

With reference toFIG. 11, a fifth construction of a jet pump assembly258is schematically illustrated. Like components are labeled with like reference numerals, with the letter “c.” Like the fuel system arrangement shown inFIG. 10, the fuel system arrangement ofFIG. 11is illustrative of a diesel fuel system including a lift pump162cpositioned outside of a bifurcated or saddle-style fuel tank242c, similar to the fuel tanks38,38a,242discussed above. However, the jet pump assembly258includes a pressure relief valve262in fluid communication with the fuel supply conduit166cof the jet pump assembly258. The pressure relief valve262is structurally similar to the pressure relief valve126of the jet pump assembly122ofFIGS. 5-7, and will not be described again in detail. Likewise, the manner of operation of the pressure relief valve262is similar to the manner of operation of the pressure relief valve126of the jet pump assembly122ofFIGS. 5-7, and will not be described again in detail. Furthermore, the manner of operation of the remaining components of the jet pump assembly258is similar to the manner of operation of those in the jet pump assembly238, and will not be described again in detail.

FIG. 12illustrates a sixth construction of a jet pump assembly266positionable in a reservoir of a fuel pump module for an internal combustion engine. The jet pump assembly266may be incorporated in either of the fuel system arrangements including the bifurcated or saddle-style fuel tanks38ofFIGS. 3 and 4. More particularly, the jet pump assembly266may be powered by pressurized fuel output from a fuel pump of the fuel pump module or by return fuel from a fuel pressure regulator of the fuel pump module.

The jet pump assembly266includes a fuel supply conduit270and a jet pump274integrally formed as a single piece with the fuel supply conduit270. The jet pump274is in fluid communication with the fuel supply conduit270to receive pressurized fuel from the fuel supply conduit270during operation of the fuel pump. With continued reference toFIG. 12, the jet pump assembly266also includes a base278integrally formed as a single piece with the fuel supply conduit270and the jet pump234. The base278defines an internal chamber279having an opening adjacent the bottom of the base278through which fuel is drawn in response to fuel being discharged through the jet pump274. The reservoir includes a receptacle (not shown) sized to receive the base278therein. An interference fit between the receptacle and the base278of the jet pump assembly266may be employed to at least partially secure the jet pump assembly266to the reservoir. Alternatively, any of a number of different fasteners or processes may be employed to secure the jet pump assembly266to the reservoir (e.g., using screws, quick-connect structures, welding, adhesives, etc.).

A one-way valve (e.g., an umbrella-style valve similar to those schematically illustrated inFIGS. 3,4,6,7, and9-11) is coupled to the bottom of the reservoir and is positioned within the internal chamber279. The discharge of fuel through the jet pump274creates a region of low pressure within the internal chamber279, thereby opening the one-way valve to allow fuel in the primary side of the fuel tank to be drawn into the internal chamber279and subsequently mixed with the fuel discharged through the jet pump274. The mixed fuel is then discharged into the reservoir to fill the reservoir. However, shortly after deactivation of the fuel pump, fuel stops flowing through the jet pump274, allowing the pressure exerted on each side of the one-way valve to equalize which, in turn, allows the valve to close. When the valve is closed, fuel in the reservoir is prevented from back-flowing through the jet pump274and siphoning to the primary side of the fuel tank.

The jet pump274also includes a nozzle280positioned adjacent the internal chamber279of the base278and a mixing tube282positioned downstream of the nozzle. As described above, discharge of fuel through the nozzle280creates a region of low pressure within the internal chamber279to open the one-way valve and draw fuel from the primary side of the fuel tank into the internal chamber279, where the fuel is mixed with fuel discharged through the nozzle280in the mixing tube282. The mixed fuel is then discharged from the mixing tube282into the reservoir.

With reference toFIG. 12, the jet pump assembly266further includes an inlet conduit286integrally formed as a single piece with the jet pump274and an anti-siphon valve290incorporated in the inlet conduit286. The inlet conduit286fluidly communicates the jet pump274and the secondary side of the bifurcated or saddle-style fuel tank to allow the jet pump274to draw fuel from the secondary side of the fuel tank, in addition to the fuel drawn from the primary side of the fuel tank as discussed above. The inlet conduit286includes a plurality of barbs294arranged about its outer peripheral surface that facilitate securing a rubber or plastic “crossover” tube (similar to the crossover tube98inFIGS. 3 and 4) to the inlet conduit286. The crossover tube extends from the inlet conduit286, over the hump of the bifurcated or saddle-style fuel tank, and into the secondary side of the fuel tank.

With continued reference toFIG. 12, the anti-siphon valve290includes a plurality of ribs298extending radially inwardly into the inlet conduit286. The ribs298are integrally formed as a single piece with the inlet conduit286. Although only two ribs298are illustrated inFIG. 12, at least three ribs298extend radially inwardly into the inlet conduit286. In addition, the ribs298are arranged symmetrically (i.e., equi-angularly spaced from each other) about a central axis of the inlet conduit286. Alternatively, the ribs298may be arranged asymmetrically about the central axis of the inlet conduit286. Each of the ribs298includes an inclined surface302toward the top of each of the ribs298. Alternatively, each of the ribs298may include a rounded corner or a ninety-degree corner toward the top of each of the ribs298.

The anti-siphon valve290includes an orifice306defined in the inlet conduit286. More particularly, the orifice306is defined within an annular insert314positioned in the inlet conduit286. The insert314may be a separate and distinct component from the inlet conduit286that is secured to the inlet conduit286during manufacture of the jet pump assembly266(e.g., by using an interference fit, welding, adhesives, etc.). Alternatively, the insert314may be integrally formed as a single piece with the inlet conduit286. The anti-siphon valve290also includes a ball318movable in the inlet conduit286between a first position, in which the ball318is seated against the top surfaces302of the ribs298, and a second position, in which the ball318is positioned adjacent the orifice306to block the flow of fuel through the orifice306. The ball318is buoyant in fuel, such that the ball318is floated to the second position to block fuel flow through the orifice306by stagnant fuel in the inlet conduit286. Alternatively, the ball318may not be buoyant in fuel, and a brief reverse flow of fuel through the inlet conduit286in response to deactivation of the fuel pump may displace the ball318from being supported by the ribs298toward the insert314. After the ball318is seated against the insert314to block the orifice306, the pressure of the stagnant fuel in the inlet conduit may provide a sufficient force to maintain the ball318against the insert314to block the orifice306. As a further alternative, the anti-siphon valve290may include a resilient member (e.g., a spring) to bias the ball318toward the insert314to block the orifice306.

In operation of the fuel pump and the jet pump assembly266, some of the pressurized fuel output by the fuel pump is diverted toward the jet pump assembly266to power the jet pump assembly266to fill the reservoir with fuel. Alternatively, return fuel from the pressure regulator may be used to power the jet pump assembly266to fill the reservoir with fuel. In either arrangement, pressurized fuel is supplied to the fuel supply conduit270which, in turn, feeds the jet pump274. As the pressurized fuel is discharged through the nozzle280of the jet pump274, a low-pressure region within the internal chamber279is created, thereby opening the one-way valve to allow fuel from the primary side of the fuel tank to be drawn into the internal chamber279of the base278. Because the inlet conduit286is positioned adjacent the nozzle280of the jet pump274and exposed to the low-pressure region within the internal chamber279, fuel is also drawn from the secondary side of the bifurcated or saddle-style fuel tank via the crossover tube, through the inlet conduit286and the opened anti-siphon valve290, and into the internal chamber279of the base278, where fuel from the primary and secondary sides of the fuel tank is mixed with the fuel discharged through the nozzle280in the mixing tube282and discharged into the reservoir to fill the reservoir.

The anti-siphon valve290is opened when the ball318is moved away from the insert314and held against the top surfaces302of the ribs298by the low-pressure region created in the inlet conduit286and the fuel flow through the inlet conduit286. Because the ribs298are spaced from each other about the central axis of the inlet conduit286, fuel flow through the inlet conduit286may occur around the ball318and through the gaps between adjacent ribs298. Such fuel flow around the ball318would also cause the ball318to be seated or held against the top surfaces302of the ribs298in the middle of the inlet conduit286(i.e., the center of the ball318would be aligned with the central axis of the inlet conduit286). Alternatively, in a configuration of the jet pump assembly266in which the ribs298are asymmetrically positioned about the central axis of the inlet conduit286(i.e., when the spacing between adjacent ribs298is unequal), the fuel flow around the ball318may cause the ball318to wedge between adjacent ribs298at a location offset from the middle of the inlet conduit286, such that the center of the ball318would be misaligned with the central axis of the inlet conduit286. This asymmetrical arrangement of the ribs298may decrease the amount of flutter experienced by the ball318during operation of the jet pump assembly266.

FIGS. 13-15illustrate a seventh construction of a jet pump assembly410positionable in a reservoir414of a fuel pump module416for an internal combustion engine. In addition to the reservoir414, other components of the fuel pump module416(e.g., a fuel pump418, one or more filters422, a check valve426, and a fuel pressure regulator430) are schematically illustrated inFIG. 14. The fuel pump module416is positioned on a primary side434of a bifurcated or saddle-style fuel tank438. As described in more detail below, the jet pump assembly410draws fuel from both the primary side434of the fuel tank438and a secondary side442of the fuel tank438into the reservoir414to fill the reservoir414and substantially immerse the fuel pump418with fuel. This allows the fuel pump418to access a substantially continuous supply of fuel regardless of the level of fuel in the primary side434or the secondary side442of the fuel tank438.

With reference toFIGS. 13 and 14, the jet pump assembly410includes a fuel supply conduit446and a first or primary jet pump450integrally formed as a single piece with the fuel supply conduit446and oriented substantially normal to the fuel supply conduit446. The primary jet pump450is in fluid communication with the fuel supply conduit446to receive pressurized fuel from the fuel supply conduit446during operation of the fuel pump418. With reference toFIG. 14, the fuel supply conduit446receives pressurized fuel directly from the output of the fuel pump418via a separate fuel supply conduit (not labeled). Specifically, the fuel pump module416also includes a throttle member454(e.g., an orifice) positioned upstream of the fuel supply conduit446to reduce the pressure of the pressurized fuel delivered to the fuel supply conduit446. For example, the throttle member454may reduce the pressure of the pressurized fuel delivered to the fuel supply conduit446from about 5 bars to about 1 bar. Alternatively, the throttle member454may be configured to reduce the pressure of the pressurized fuel delivered to the fuel supply conduit446by a different amount.

With reference toFIG. 15, the jet pump assembly410may be positioned within the fuel pump module416such that the fuel supply conduit446receives “return” fuel from the fuel pressure regulator430to power the primary jet pump450. The fuel pump418is sized to deliver fuel to the engine at a maximum flow rate and pressure. The fuel pressure regulator430provides a regulated supply of fuel to the engine that is often less than the maximum flow rate and pressure that the fuel pump418is capable of providing. The fuel pressure regulator430, therefore, returns excess fuel that is not needed by the engine to the reservoir414to fill the reservoir414. More particularly, the excess or return fuel from the fuel pressure regulator430is used to power the primary jet pump450before being returned to the reservoir414.

With reference toFIG. 13, the jet pump assembly410also includes a base458integrally formed as a single piece with the fuel supply conduit446and the primary jet pump450. The base458defines an internal chamber460having an opening462adjacent the bottom of the base458through which fuel is drawn in response to fuel being discharged through the primary jet pump450. The reservoir414includes a receptacle466sized to receive the base458therein. An interference fit between the receptacle466and the base458of the jet pump assembly410may be employed to at least partially secure the jet pump assembly410to the reservoir414. Alternatively, any of a number of different fasteners or processes may be employed to secure the jet pump assembly410to the reservoir414(e.g., using screws, quick-connect structures, welding, adhesives, etc.).

A one-way valve470(e.g., an umbrella-style valve) is coupled to the bottom of the reservoir414and is positioned within the internal chamber460. As is discussed in more detail below, the discharge of fuel through the primary jet pump450creates a region of low pressure within the internal chamber460, thereby opening the one-way valve470to allow fuel in the primary side434of the fuel tank438to be drawn into the internal chamber460and subsequently mixed with the fuel discharged through the primary jet pump450. The mixed fuel is then discharged into the reservoir414to fill the reservoir414. However, shortly after de-activation of the fuel pump418, fuel stops flowing through the primary jet pump450, allowing the pressure exerted on each side of the one-way valve470to equalize which, in turn, allows the valve470to close. When the valve470is closed, fuel in the reservoir414is prevented from back-flowing through the primary jet pump450and siphoning to the primary side434of the fuel tank438.

With continued reference toFIG. 13, the primary jet pump450includes a nozzle474positioned adjacent the internal chamber460of the base458and a mixing tube478positioned downstream of the nozzle474. As described above, discharge of fuel through the nozzle474creates a region of low pressure within the internal chamber460to open the one-way valve470and draw fuel from the primary side434of the fuel tank438into the chamber460, where the fuel is mixed with fuel discharged through the nozzle474in the mixing tube478. The mixed fuel is then discharged from the mixing tube478into the reservoir414.

The jet pump assembly410also includes a second or secondary jet pump482integrally formed as a single piece with the fuel supply conduit446and the first or primary jet pump450. The secondary jet pump482is in fluid communication with the fuel supply conduit446to receive pressurized fuel from the fuel supply conduit446during operation of the fuel pump418. The primary and secondary jet pumps450,482are fluidly connected to the fuel supply conduit446in a parallel arrangement, such that the pressure of the fuel delivered to each of the primary and secondary jet pumps450,482is substantially similar (see alsoFIGS. 14 and 15). Alternatively, the throttle member454may be associated with only one of the primary and secondary jet pumps450,482such that one of the jet pumps450,482receives fuel at a higher pressure than the other. Further, an additional throttle member454may be associated with one of the primary and secondary jet pumps450,482such that one of the jet pumps450,482receives fuel at a lower pressure than the other.

With reference toFIG. 13, the secondary jet pump482includes a nozzle486and a mixing tube490positioned downstream of the nozzle486. In the illustrated construction of the jet pump assembly410, the mixing tubes478,490of the first and second jet pumps450,482are stacked one on top of the other (i.e., vertically aligned) such that the mixing tubes478,490share a common wall494. Alternatively, the mixing tubes478,490may be situated side-by-side or horizontally aligned, or situated diagonally with respect to one another, while sharing a common wall. Each of the primary and secondary jet pumps450,482includes a plug (e.g., a ball bearing498) positioned within an aperture502formed in a respective outer wall of the jet pumps450,482while molding the fuel supply conduit446, the base458, and the jet pumps450,482as a single piece. Specifically, the apertures502may be formed by respective slides used in an injection molding process to mold the passageways of the nozzles474,486in the respective jet pumps450,482. As such, insertion of the ball bearings498into the apertures502(via an interference fit, for example) effectively blocks the apertures502to substantially prevent fuel flow through the apertures502.

The jet pump assembly410also includes a plug506integrally formed as a single piece with the secondary jet pump482. In the illustrated construction of the jet pump assembly410, the plug506and the mixing tube490are connected by an integral tether510to close an end514of the mixing tube490opposite the nozzle486. As a result, fuel is prevented from being discharged from the end514of the mixing tube490. Alternatively, the plug506may be configured as a ball bearing that is a separate and distinct component from the mixing tube490.

With continued reference toFIG. 13, the jet pump assembly410further includes an inlet conduit518integrally formed as a single piece with the secondary jet pump482. The inlet conduit518fluidly communicates the secondary jet pump482and the secondary side442of the bifurcated or saddle-style fuel tank438to allow the secondary jet pump482to draw fuel from the secondary side442of the fuel tank438. The inlet conduit518includes an opening522positioned adjacent the nozzle486through which fuel is drawn into the mixing tube490as a result of a low-pressure region surrounding the nozzle486and in the inlet conduit518in response to fuel discharge through the nozzle486. In the illustrated construction of the jet pump assembly410, the inlet conduit518extends substantially perpendicularly from the mixing tube490and in a direction substantially parallel with the fuel supply conduit446. Alternatively, the inlet conduit518may extend from the mixing tube490at an oblique angle. The inlet conduit518includes a plurality of barbs526arranged about its outer peripheral surface that facilitate securing a rubber or plastic “crossover” tube530to the inlet conduit518. Such a crossover tube530(shown schematically inFIGS. 14 and 15) extends from the inlet conduit518, over the hump of the bifurcated or saddle-style fuel tank438, and into the secondary side442of the fuel tank438.

With reference toFIG. 13, the jet pump assembly410includes a bracket534integrally formed as a single piece with the inlet conduit518. The bracket534includes a substantially circular cross-sectional shape and facilitates alignment of an inlet end538of the fuel supply conduit446with another fuel supply conduit (not shown) fluidly connected to either the output of the fuel pump418or a bypass port of the fuel pressure regulator430, as shown inFIGS. 14 and 15. Alternatively, the bracket may be omitted from the jet pump assembly410.

With reference toFIG. 13, the jet pump assembly410also includes a stand pipe542integrally formed as a single piece with the secondary jet pump482. In the illustrated construction of the jet pump assembly410, the stand pipe542extends substantially perpendicularly from the mixing tube490and in a direction substantially parallel with the inlet conduit518and the fuel supply conduit446. Alternatively, the stand pipe542may extend from the mixing tube490at an oblique angle. The stand pipe542includes distal open546end that remains exposed or uncovered when the jet pump assembly410is positioned in the reservoir414. As is described in more detail below, the stand pipe542substantially prevents fuel in the reservoir414, below the distal open end546of the stand pipe542and outside of the jet pump assembly410, from siphoning out of the reservoir414and into the secondary side442of the bifurcated or saddle-style fuel tank438.

In operation of the fuel pump418and the jet pump assembly410, some of the pressurized fuel output by the fuel pump418is diverted toward the jet pump assembly410to power the jet pump assembly410and fill the reservoir414with fuel (seeFIG. 14). As discussed above, the pressure of the diverted fuel is reduced by the throttle member454prior to entering the fuel supply conduit446. The pressurized fuel in the fuel supply conduit446then feeds both the primary and secondary jet pumps450,482. As the pressurized fuel is discharged through the nozzle474of the primary jet pump450, a low-pressure region within the internal chamber460of the base458is created, thereby opening the one-way valve470to allow fuel from the primary side434of the fuel tank438to be drawn into the internal chamber460. Fuel drawn into the internal chamber460of the base458is mixed with the fuel discharged through the nozzle474in the mixing tube,478and is subsequently discharged into the reservoir414to fill the reservoir414. While this occurs, pressurized fuel discharged through the nozzle486of the secondary jet pump482creates a low-pressure region surrounding the nozzle486and within the inlet conduit518, thereby drawing fuel from the secondary side442of the fuel tank438into the inlet conduit518(via the crossover tube530). Fuel drawn through the inlet conduit518is mixed with fuel discharged through the nozzle486in the mixing tube490, and the mixed fuel is discharged upwardly through the stand pipe542and into the reservoir414to fill the reservoir414with fuel from the secondary side442of the fuel tank438.

Upon deactivation of the fuel pump418, the one-way valve470closes to substantially prevent fuel in the reservoir414from back-flowing through the primary jet pump450and siphoning to the primary side434of the fuel tank438. Some fuel in the reservoir414may, however, back-flow through the stand pipe542, the secondary jet pump482, and the inlet conduit518and siphon to the secondary side442of the fuel tank438. As the level of fuel in the reservoir414reaches the distal open end546of the stand pipe542, the remaining fuel in the stand pipe542, the secondary jet pump482, and the inlet conduit518may continue to siphon into the secondary side442of the fuel tank438. However, any fuel in the reservoir414below the distal open end546of the stand pipe542and outside of the jet pump assembly410is prevented from siphoning into the secondary side442of the fuel tank438, thereby maintaining a sufficient supply of fuel in the reservoir414in anticipation of reactivation of the fuel pump418.

With reference toFIG. 15, operation of the jet pump assembly410is substantially similar as that described above with respect toFIG. 14, except the jet pump assembly410is powered by return fuel from the fuel pressure regulator430rather than receiving fuel directly from the output of the fuel pump418. The return fuel provided by the fuel pressure regulator430has a reduced pressure compared to that of the fuel supplied to the engine, such that a throttle member454(e.g., throttle member454) is not required upstream of the fuel supply conduit446.