The present disclosure relates generally to a fuel pump assembly that includes an electric motor fuel pump and a fluid driven fuel pump.
Fuel systems for combustion engines can include a fuel pump assembly that pumps fuel from a fuel tank to an engine. The fuel pump generally is carried by some structure either within or outside of the fuel tank. Fuel is taken into the fuel pump through an inlet, the pressure of the fuel is increased, and the fuel is discharged from the fuel pump and delivered to the engine.
In at least some implementations, a fuel pump assembly includes a reservoir having an internal volume and an inlet that communicates with the internal volume, a primary fuel pump having an inlet in communication with the internal volume, an outlet through which fuel is discharged under pressure, an electric motor and a pumping element driven by the electric motor to take fuel into the inlet and discharge fuel from the outlet and a secondary fuel pump. The secondary fuel pump has a body that defines a first inlet, a second inlet and an outlet. The first inlet receives at least some of the fuel discharged from the primary fuel pump outlet and a nozzle is carried by the body or otherwise communicated with the first inlet so that fuel that flows out of the nozzle flows into the body via the first inlet. The second inlet is in communication with the reservoir inlet, and the outlet is in communication with the internal volume. The flow of fuel through the nozzle creates a drop in pressure in the area of the second fuel inlet to draw fuel from the fuel source through the second fuel inlet and the fuel drawn in through the second fuel inlet is combined with the flow of fuel from the nozzle. The combined fuel flows are discharged from the secondary fuel pump outlet and into the internal volume.
In at least some implementations, the nozzle is received at least partially in the body and the body defines an area downstream of the nozzle that is larger in size than the flow area of the nozzle. The body may be formed as a single piece of material such that the first inlet, second inlet and the outlet are features integrally formed in the same component. The body may be formed from a material conductive to electrostatic charges.
In at least some implementations, a flow controller is carried by the reservoir and fuel flow from the secondary fuel pump outlet is directed into the reservoir, and the flow controller includes a cavity and the outlet is defined at least in part by an outlet tube having an end that is received in the cavity. The outlet may be coupled to a first end of an outlet tube and a second end of the outlet tube is received within the cavity. The flow controller may include a surface that is at an angle of between 45 and 90 degrees relative to the direction of fuel flow out of the secondary fuel pump outlet. The flow controller may include an opening above the level of the second end of the outlet tube relative to the direction of the force of gravity.
In at least some implementations, at least a portion of the second inlet or of a passage coupled to the second inlet is at an acute included angle of between 0 and 60 degrees relative to the direction of the force of gravity. In at least some implementations, the outlet is coupled to a first end of an outlet tube, and wherein the outlet tube is bent and includes a portion that is located above a height of the second outlet relative to the force of gravity.
In at least some implementations, a pick-up tube has a first end coupled to the reservoir and communicated with the inlet of the reservoir, and the pick-up tube has a second end spaced from the reservoir. In at least some implementations, an intake tube is coupled at a first end to the reservoir and communicated with the inlet of the reservoir, and the intake tube has a second end coupled to the second inlet of the body. In at least some implementations, an intake tube is coupled at a first end to the second inlet of the body and a second end that is remote from the reservoir. The intake tube may extend from within the internal volume to a location outside of the internal volume. The intake tube may be defined in part by a passage formed in the reservoir.
In at least some implementations, a carrier is received within the reservoir internal volume and has a wall that supports the primary fuel pump within the internal volume, and wherein the body is formed in the same piece of material as at least a portion of the carrier.
In at least some implementations, the primary fuel pump includes an outlet body that defines the outlet of the primary fuel pump, and a hollow projection that defines a second outlet of the primary fuel pump, and a portion of the body of the secondary fuel pump that defines the first inlet is received over at least part of the hollow projection so that the body of the secondary fuel pump is coupled to the outlet body.
The following detailed description of certain embodiments and best mode will be set forth with reference to the accompanying drawings, in which:
Referring in more detail to the drawings,
The reservoir 12 may be of any desired shape and provide any desired internal volume 22. As shown in
A second inlet 36 (
To retain the reservoir 12 within the fuel tank 24, the assembly may include a mounting flange 40 (part of which is shown in
The primary fuel pump 14 may include an electric motor 50 and a pumping element 52 driven by the motor 50. The pumping element 52 creates a pressure drop at an inlet 54 of the fuel pump 14 to draw fuel into the inlet 54, and increases the pressure of fuel taken into the pumping element 52 so that fuel is discharged from the fuel pump 14 under pressure. The pumping element 52 may be a of a positive displacement type, like a gerotor or screw pump, or a centripetal pump like a turbine type pump. The fuel pump inlet 54 may be arranged adjacent to the bottom wall 28 of the reservoir 12 so that all or nearly all of the fuel within the internal volume 22 can be taken into the primary fuel pump 14. A fuel filter 56 may be arranged at the inlet 54 and within the internal volume 22 to filter fuel before the fuel is drawn into the primary fuel pump 14. In addition to or instead, a fuel filter may be provided at one or both inlets 30, 32 of the reservoir 12, at the free end 39 of the pick-up tube 35 or at the second end 97 of the intake tube 34 to filter fuel as it enters the reservoir internal volume 22 and prior to being pumped by the primary fuel pump 14.
The motor 50 and pumping element 52 may be carried within a housing 60 of the fuel pump 14 which may include an inlet body 62 and an outlet body 64 at opposite ends of a cylindrical casing 66. The casing 66 may be fixed to the inlet and outlet bodies 62, 64 in any suitable way including crimping the ends of the casing 66 to the bodies and/or by weld, adhesive, fasteners or the like. The motor 50 and pumping element 52 may be received between the inlet and outlet bodies 62, 64, and may be supported at least in part by the bodies 62, 64. The inlet body 62 may define the inlet 54 to the fuel pump 14 through which fuel is taken in by the pumping element 52, and the outlet body 64 may define one or more outlets of the fuel pump 14 through which fuel is discharged from the fuel pump 14. In the example shown, the fuel pump 14 includes a first fuel outlet 68 through which fuel is discharged to the engine and a second fuel outlet 70 through which a flow of fuel is provided for the secondary fuel pump 20. The first and second fuel outlets 68, 70 may be defined at least in part by ports or passages in the outlet body 64. The first fuel outlet 68 may be coupled to one end of a tube 72 that has its other end coupled to a passage through the mounting flange 40. A fuel line may be coupled to the mounting flange 40 outboard of the fuel tank 24 and lead to a fuel rail or other component for delivery of fuel to the engine. In this way, fuel may be delivered from within the fuel tank 24 to a location outboard of the fuel tank. The outlet body 64 may include or receive one or more electrical connectors 74 or terminals via which electrical power is provided to the motor 50.
To retain the position of the fuel pump 14 within the reservoir 12, a carrier 76 in the internal volume 22 may receive, retain and/or engage at least part of the fuel pump 14. The carrier 76 may be formed separate from the reservoir main body 18 and coupled thereto in assembly, or it may be defined by one or more internal walls or structural features of the main body 18 that engage or support the fuel pump 14 within the reservoir, or some combination of the separately formed and integrally formed features. In the example shown in
The first fuel outlet 68 and second fuel outlet 70 may both extend from and communicate with an interior 92 of the fuel pump housing 60 so that each receive fuel at about the same pressure. The outlets 68, 70 may be provided in any desired orientation and are shown as being separate passages in the outlet body 64 that are parallel or generally parallel with each other and parallel or generally parallel to a rotary axis 94 of the motor 50 (where generally in this instance means within 15 degrees). The second outlet 70 could instead be a tap, branch or “T” off of the first outlet 68, or vice versa, or the first and second outlets 68, 70 can be oriented in any other desired manner including implementations wherein one or both of the outlets 68, 70 extend through the inlet body 62 and/or casing 66 rather than the outlet body 64. The second outlet 70 may lead to or define part of the secondary pump 20 and provides an input fuel flow to the secondary fuel pump 20.
The secondary pump 20 utilizes the flow of fuel from the second outlet 70 to create a drop in a pressure that is communicated with the reservoir inlet 32 (and a pick-up tube 35 if included) to draw fuel from the fuel tank 24 through the reservoir inlet 32 (and pick-up tube 35). In at least some implementations, the secondary pump 20 includes a nozzle 96, jet or restriction that increases the velocity of fuel flowing therethrough and which leads to a larger area 98, which may be defined by part of a venturi or tapered portion of a passage or tube 100. Hence, the secondary fuel pump 20 may be a so-called jet pump. The increase in velocity of fuel discharged from the nozzle 96 causes a decrease in pressure and the area 98 downstream of the nozzle 96 which is communicated with the reservoir inlet 32 (and/or a pick-up tube) through the intake tube 34. The intake tube 34 is coupled at one end 97 (
In at least some implementations, such as is shown in
The second inlet 106 is communicated with the area 98 downstream of the nozzle 96 and receives or is otherwise coupled to the second end 99 of the intake tube 34 to receive fuel drawn through the reservoir inlet 32. The second inlet 106 may be defined by a nipple or projection onto which the second end 99 of the intake tube 34 is fitted (e.g. in a fluid-tight manner). As shown in
The outlet 108 receives fuel from one or both inlets 104, 106 of the second pump body 102 and is communicated with the internal volume 22 so that at least some and up to all of the fuel that exits the outlet 108 enters the internal volume 22. The outlet 108 may be coupled to a first end 112 of an outlet tube 114 that has its second end 116 received in the internal volume 22. The outlet tube 114 may be bent and include a portion located above the height of the second outlet 70, where above is relative to the force of gravity. The second end 116 of the outlet tube 114 may be received in or communicated with a flow controller 118.
As shown in
The second pump body 102 may be a simple, molded plastic component that integrally includes, and which may be formed in a single body, the two inlets 104, 106 and the outlet 108 all in communication with each other within the body 102. The second pump body 102 may be formed from an electrically conductive material that may facilitate the transmission away from the primary pump of electrostatic charges that may develop in the fuel pump assembly. The second pump body 102 may directly engage the primary pump 14, such as at the outlet body 64, and so may further be coupled to a grounded or metal element in or of the pump 14 to facilitate transmission of electrostatic charges and thereby reduce or eliminate the build-up of an electrostatic charge beyond a threshold, such as a charge that may cause a spark. An example may include implementations wherein the second outlet is or includes a brass part that contacts a brush spring of the motor (when a brushed motor is used in the primary fuel pump 14). In at least some implementations, the conductivity range or resistance range of the second pump body 102 is between 105 and 109 ohms per square.
The second pump body 102 may support, locate and retain the position of the intake tube 34 and outlet tube 114. The first inlet 104 and the outlet 108 may be arranged in-line with the flow of fuel out of the second outlet 70 of the primary fuel pump 14, which may be oriented vertically, against the force of gravity (or generally vertically which is within 20 degrees of vertical). Of course, other orientations may be used. The second pump body 102 may be of a relatively small size and may fit within a relatively small diameter reservoir 12, as desired. In at least some implementations, the second pump body 102 may be received within an envelope defined by the pump housing 60, in other words, the second pump body 102 may be axially offset but radially overlapped by the pump housing 60. That is, the second pump body 102 does not, in at least some implementations, extend radially outwardly relative to the primary pump housing 60 and is within a vertical extension of the periphery of the primary pump housing 60.
The jet or restriction 96 for the secondary fuel pump 20 may be defined as a molded-in feature of the second pump body 102, may be a separate insert that is press-fit or otherwise secured to the second pump body 102, or may be defined by or carried by the second outlet 70 of the outlet body 64. In the example shown, the second outlet 70 includes a reduced diameter section or jet 96 integrally provided within the outlet body 64 of the primary fuel pump 14. Providing the jet within the second pump body 102 may facilitate use of the same primary pump 14 in different applications needing different jet sizes or flow characteristics. Further, the second pump body 102 may include a tapered passage 100 that includes a reduced size in the area 98 closer to the nozzle or jet 96 and which increases in size toward the outlet 108. This tapered passage 100 may define a diverging portion of the passage or outlet 108 which may function like a diverging portion of a venturi to improve the pressure drop in the area of the second inlet 106 and improve the performance and efficiently of the secondary fuel pump 20.
Further, as shown in
It is to be understood that the foregoing description is not a definition of the invention, but is a description of one or more preferred embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. For example, a method having greater, fewer, or different steps than those shown could be used instead. All such embodiments, changes, and modifications are intended to come within the scope of the appended claims.
As used in this specification and claims, the terms “for example,” “for instance,” “e.g.,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.
This application claims the benefit of U.S. Provisional Application Ser. No. 62/769,810 filed on Nov. 20, 2018 the entire contents of which are incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2019/059346 | 11/1/2019 | WO | 00 |
Number | Date | Country | |
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62769810 | Nov 2018 | US |