Patent Description:
The present disclosure relates to fuel pumps, and more particularly, to solenoid actuated fuel pumps.

<CIT> discloses that substantially the entirety of the components is contained within a casing. There is also no microcontroller provided, which controls the operation of the fuel pump.

<CIT> a control unit which could help to handle fuel flow differentials of a longer fuel path. A positioning of a filter in not disclosed which would then identify that the fuel pump and fuel filter could be kept usefully further apart for serviceability.

German Patent Application <CIT> discloses a filter positioned in the traditional way as an integrated component as opposed to a component set apart. Additionally, no microcontroller is disclosed which is an integral part of the fuel pump.

A fuel pump is a frequently (but not always) essential component on a car or other internal combustion engine device. Many engines (older motorcycle engines in particular) do not require any fuel pump at all, requiring only gravity to feed fuel from the fuel tank or under high pressure to the fuel injection system. Often, carbureted engines use low pressure mechanical pumps that are mounted outside the fuel tank, whereas fuel injected engines often use electric fuel pumps that are mounted inside the fuel tank (and some fuel injected engines have two fuel pumps: one low pressure/high volume supply pump in the tank and one high pressure/low volume pump on or near the engine). Fuel pressure needs to be within certain specifications for the engine to run correctly. If the fuel pressure is too high, the engine will run rough and rich, not combusting all of the fuel being pumped making the engine inefficient and a pollutant. If the pressure is too low, the engine may run lean, misfire, or stall.

Plunger-type pumps are a type of positive displacement pump that contain a pump chamber whose volume is increased and/or decreased by a plunger moving in and out of a chamber full of fuel with inlet and discharge stop-check valves. It is similar to that of a piston pump, but the high-pressure seal is stationary while the smooth cylindrical plunger slides through the seal. These pumps typically run at a higher pressure than diaphragm type pumps. A spring is used to pull the plunger outward creating a lower pressure pulling fuel into the chamber from the inlet valve.

Typically, back pressure is present at the outlet port of a solenoid pump and limits Operation of the pump, that is, the pump can operate only up to a certain back pressure level. In general, the back pressure works against the spring used to bias the plunger. For example, when the back pressure is greater than the biasing force of the spring, the pumping cycle is terminated (the plunger cannot return to a "rest" position when the coil is de-energized). The known use of linear springs limits the back pressure under which known solenoid pumps can operate. The spring biasing force must be relatively lower to enable the initiation of the plunger displacement when the coil is energized. Since the spring is linear, only the same relatively lower biasing force is available to counteract the back pressure. Known solenoid pumps cannot operate with a backpressure over about <NUM> kPa.

Known solenoid pumps are difficult to assemble and can be large or bulky. Additionally, known solenoid pumps must be totally removed from its rather permanent plumbing in order that it be serviced (i.e., to replace the filter therein).

Thus, there is a long-felt need for a solenoid fuel pump that is compact, easy to assemble, and can be serviced without being removed from its plumbing. There is also a longfelt need for a solenoid pump, the timing of which can be controlled via a microcontroller and/or an external signal source. There is also a long-felt need for a solenoid pump that is entirely watertight and prevents the ingress of water and other foreign substances around the lead wires.

The solution is provided by a fuel pump as defined in claim <NUM>, said fuel pump comprising a case, including a first section comprising a hub and a hole, a second section, the second section comprising a threading and circumferentially arranged around the first section, wherein a radial space is arranged between the first section and the second section, an inlet in fluid communication with the radial space, a housing chamber arranged adjacent to the first section, and an outlet in fluid communication with the hole, a filter bowl removably connected to the second section, the filter bowl disposed outside the case and providing a fuel path outside the case, the filter bowl fluidly connecting the radial space with the hole and axially extended from the second section, a filter engaged with the hub, the filter partially arranged in the filter bowl and positioned slidably and circumferentially around the hub, a valve assembly arranged at least partially in the first section and at least partially in the housing chamber, a coil operatively arranged to apply a magnetic field to the valve assembly to selectively displace fluid therethrough, and a circuit connected to the coil, wherein the circuit includes a microcontroller operatively arranged to control current supplied to the coil.

In some embodiments, the fuel pump further comprises a bobbin arranged concentrically around the valve assembly, wherein the coil is arranged concentrically around the bobbin. In some embodiments, the fuel pump further comprises a first metal plate arranged on a first axial side of the coil, a second metal plate arranged on a second axial side of the coil, opposite the first axial side, and a metal sleeve arranged circumferentially around the coil. According to the invention the fuel pump comprises a circuit connected to the coil. According to the invention the circuit comprises a microcontroller operatively arranged to control current supplied to the coil. In some embodiments, the case further comprises a port electrically connected to the circuit. In some embodiments, the valve assembly comprises a fuel chamber tube including a first end and a second end, a check valve assembly arranged in the fuel chamber tube at the first end, and a plunger assembly slidably arranged in the fuel chamber tube at the second end. In some embodiments, the check valve assembly comprises a first seat including a first side and a second side, a first component axially spaced from the first seat, a check valve displaceably arranged between the first seat and the first component, and a first spring operatively arranged to bias the check valve in a first axial direction, towards the first seat. In some embodiments, the check valve assembly further comprises a seal, the seal being integrally formed and engaged with both the first side and the second side of the first seat. In some embodiments, the plunger assembly comprises a tube including a second seat, a third seat, and a through-bore, a fourth seat engaged with the second seat and including a radially inward facing surface, a second component engaged with the second seat, and a plunger displaceably arranged between the fourth seat and the second component. In some embodiments, the check valve assembly further comprises a second spring arranged in a fuel chamber between the check valve assembly and the plunger assembly to bias the plunger assembly in a second axial direction, opposite the first axial direction. In some embodiments, the second spring is frusto-conical. In some embodiments, when the plunger assembly is displaced in the first axial direction, the check valve sealingly engages the first side of the seat and the plunger is spaced apart from the radially inward facing surface allowing fluid flow into the through-bore, and when the plunger assembly is displaced in the second axial direction, the plunger is sealingly engaged with the radially inward facing surface and the check valve is spaced apart from the second surface allowing fluid flow into the fuel chamber. According to the invention the fuel pump further comprises a filter engaged with the hub, wherein the filter bowl is operatively arranged to secure the filter to the case.

According to aspects illustrated herein, there is provided a fuel pump, comprising a case, including a first section comprising a hub and a hole, a second section concentrically arranged around the first section, wherein a radial space is arranged between the first section and the second section, an inlet in fluid communication with the radial space, a housing chamber arranged adjacent to the first section and the second section, and an outlet in fluid communication with the hole, a filter bowl removably connected to the second section, the filter bowl fluidly connecting the radial space with the hole, a valve assembly arranged at least partially in the first section and at least partially in the housing chamber, the valve assembly including a fuel chamber tube comprising a first end and a second end, a check valve assembly arranged in the fuel chamber tube at the first end, and a plunger assembly slidingly arranged in the fuel chamber tube at the second end, and a solenoid coil concentrically arranged around the plunger assembly, the solenoid coil operatively arranged to produce a magnetic field to displace the plunger assembly in a first axial direction such that fluid is selectively displaced from the inlet to the outlet.

In some embodiments, the fuel pump further comprises a circuit connected to the solenoid coil, the circuit comprising a microcontroller operatively arranged to control power supplied to the solenoid coil. In some embodiments, the check valve assembly comprises a first seat including a first side and a second side, a seal integrally formed and engaged with both the first side and the second side, a first component axially spaced from the first seat, a check valve displaceably arranged between the first seat and the first component, and a first spring operatively arranged to bias the check valve in the first axial direction, towards the first seat. In some embodiments, the plunger assembly comprises a tube including a through-bore, a second seat engaged with the tube and including a radially inward facing surface, a second component engaged with the tube, and a plunger displaceably arranged between the second seat and the second component, wherein a spring is arranged between the plunger assembly and the check valve assembly to bias the plunger assembly in a second axial direction, opposite the first axial direction. In some embodiments, when the plunger assembly is displaced in the first axial direction, the check valve sealingly engages the first side and the plunger is spaced apart from the radially inward facing surface allowing fluid flow into the through-bore, and when the plunger assembly is displaced in the second axial direction, the plunger is sealingly engaged with the radially inward facing surface and the check valve is spaced apart from the second surface allowing fluid flow into the fuel chamber tube.

According to aspects illustrated herein, there is provided a fuel pump, comprising a case, including a first section comprising a hub and a hole, a second section concentrically arranged around the first section, wherein a radial space is arranged between the first section and the second section, an inlet in fluid communication with the radial space, a housing chamber arranged adjacent to the first section and the second section, and an outlet in fluid communication with the hole, a filter removably connected to the hub, a filter bowl removably connected to the second section and operatively arranged to secure the filter to the case, the filter bowl fluidly connecting the radial space with the hole, a valve assembly arranged at least partially in the first section and at least partially in the housing chamber, the valve assembly including a fuel chamber tube comprising a first end and a second end, a check valve assembly arranged in the fuel chamber tube at the first end, and a plunger assembly slidingly arranged in the fuel chamber tube at the second end, and a solenoid coil concentrically arranged around the plunger assembly, the solenoid coil operatively arranged to produce a magnetic field to displace the plunger assembly in a first axial direction such that fluid is selectively displaced from the inlet to the outlet.

These and other objects, features, and advantages of the present disclosure will become readily apparent upon a review of the following detailed description of the disclosure, in view of the drawings and appended claims.

Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which:.

At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements. It is to be understood that the claims are not limited to the disclosed aspects.

Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the claims.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure pertains. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the example embodiments. The assembly of the present disclosure could be driven by hydraulics, electronics, pneumatics, and/or springs.

It should be appreciated that the term "substantially" is synonymous with terms such as "nearly," "very nearly," "about," "approximately," "around," "bordering on," "close to," "essentially," "in the neighborhood of," "in the vicinity of," etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term "proximate" is synonymous with terms such as "nearby," "close," "adjacent," "neighboring," "immediate," "adjoining," etc., and such terms may be used interchangeably as appearing in the specification and claims. The term "approximately" is intended to mean values within ten percent of the specified value.

By "non-rotatably connected" or "non-rotatably secured" elements, we mean that: the elements are connected so that whenever one of the elements rotate, all the elements rotate; and relative rotation between the elements is not possible. Radial and/or axial movement of non-rotatably connected elements with respect to each other is possible, but not required. By "rotatably connected" elements, we mean that the elements are rotatable with respect to each other.

Moreover, as used herein, "and/or" is intended to mean a grammatical conjunction used to indicate that one or more of the elements or conditions recited may be included or occur. For example, a device comprising a first element, a second element and/or a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or, a device comprising a second element and a third element.

Adverting now to the figures, <FIG> is a perspective view of fuel pump <NUM>. <FIG> is a perspective view of fuel pump <NUM>. <FIG> is a exploded perspective view of fuel pump shown <NUM>. <FIG> is a cross-sectional view of fuel pump <NUM> taken generally along line <NUM>-<NUM> in <FIG>. <FIG> is a cross-sectional view of fuel pump <NUM> taken generally along line <NUM>-<NUM> in <FIG>. Fuel pump <NUM> generally comprises filter bowl <NUM>, filter <NUM>, cover <NUM>, case <NUM>, circuit or circuit board <NUM>, coil <NUM>, and valve assembly <NUM>. The following description should be read in view of <FIG>.

Filter bowl <NUM> comprises hub <NUM> and threading <NUM>. Filter bowl <NUM> is operatively arranged to secure filter <NUM> to case <NUM>. In some embodiments, and as shown, filter bowl <NUM> is connected to case <NUM> via threading <NUM>. Threading <NUM> engages threading <NUM> of case <NUM>. When filter bowl <NUM> is connected to case <NUM>, filter <NUM> is secured between hub <NUM> and case <NUM>. Specifically, filter <NUM> engages hub <NUM> of filter bowl <NUM> and hub <NUM> of case <NUM> to ensure proper alignment and position of filter <NUM>. As shown in <FIG>, filter <NUM> is positioned circumferentially around hub <NUM> and hub <NUM> (i.e., filter <NUM> is a sleeve that is slid over hub <NUM> and hub <NUM> at each end). In some embodiments, filter <NUM> comprises support cage <NUM>. In such embodiments, filter <NUM> and support cage <NUM> engage hub <NUM> of filter bowl <NUM> and hub <NUM> of case <NUM> to ensure proper alignment and position of filter <NUM>. In some embodiments, filter bowl <NUM> is transparent, which allows filter <NUM> to be seen so as to indicate when replacement is necessary. In some embodiments, filter bowl <NUM> is translucent. In some embodiments, filter bowl <NUM> is opaque. Filter bowl <NUM> and filter <NUM> are operatively arranged to be removably connected to case <NUM>. The threaded connection between filter bowl <NUM> and case <NUM> allow for easy replacement of filter <NUM>.

Case <NUM> comprises inlet <NUM>, section <NUM>, section <NUM>, fuel chamber <NUM>, and housing chamber <NUM>. Space <NUM> is a radially space arranged radially between section <NUM> and section <NUM>. Sections <NUM> and <NUM> are generally radial walls. Section <NUM> comprises hub <NUM>, which is operatively arranged to engage filter <NUM>, hole <NUM>, and fuel chamber <NUM>. In some embodiments, section <NUM> is frusto-conical (i.e., section <NUM> decreases in diameter in axial direction AD1). Section <NUM> is arranged radially outward of, and circumscribes, section <NUM>. Section <NUM> comprises threading <NUM>, which is arranged to threadably engage threading <NUM> to connect filter bowl <NUM> with case <NUM>. In some embodiments, inlet <NUM> comprises fitting <NUM>. In some embodiments, a longitudinal axis of inlet <NUM> is perpendicular to a longitudinal axis of hole <NUM> and outlet <NUM>. In some embodiments, a longitudinal axis of inlet <NUM> is arranged at an angle with respect to a longitudinal axis of hole <NUM> and outlet <NUM>, and that angle being greater than <NUM> degrees and less than <NUM> degrees. In some embodiments, fitting <NUM> is a metal insert and includes threading on a its radially inward facing surface. In some embodiments, fitting <NUM> is molded within outlet <NUM>. In some embodiments, a seal is arranged around fitting <NUM> to create a seal between fitting <NUM> and case <NUM>. Housing chamber <NUM> is arranged adjacent to fuel chamber <NUM>. Fuel chamber <NUM> at least partially houses valve assembly <NUM>. In some embodiments, seal 94A is arranged radially between valve assembly <NUM> and section <NUM>. Housing chamber <NUM> at least partially houses valve assembly <NUM>. Housing chamber <NUM> houses circuit <NUM>, coil bobbin <NUM>, coil <NUM>, pole <NUM>, and pole <NUM>. Case <NUM> further comprises connector port <NUM> which allows an electrical connection between a power source and circuit <NUM>, and coil <NUM>. In some embodiments, connector port <NUM> may comprise a connector geometry that eliminates the need for external lead wires, for example, Deutsch connector P/N: DT04-4P. This connector geometry is arranged in such a way as to accept the connector pins, namely, terminal(s) <NUM>, from circuit <NUM> that will be described in greater detail below. In some embodiments, case <NUM> is injection molded.

Cover <NUM> comprises outlet <NUM>, protrusion <NUM>, and recess or hole <NUM>. Cover <NUM> is operatively arranged to be connected to case <NUM> to secure various components of fuel pump <NUM> therein. In some embodiments, cover <NUM> is connected to case <NUM> via ultrasonic weld; however, it should be appreciated that any suitable method for connecting cover <NUM> and case <NUM> may be used, for example, adhesives, bolts, screws, rivets, pins, nails, welding, soldering, etc. Protrusion <NUM> extends at least partially into housing chamber <NUM>, in axial direction AD1, and at least partially engages valve assembly <NUM> via recess <NUM>, which aligns valve assembly <NUM> with outlet <NUM>. In some embodiments, outlet <NUM> comprises fitting <NUM>. In some embodiments, fitting <NUM> is a metal insert and includes threading on a its radially inward facing surface. In some embodiments, fitting <NUM> is molded within outlet <NUM>. In some embodiments, a seal is arranged around fitting <NUM> to create a seal between fitting <NUM> and cover <NUM>. In some embodiments, seal 94B is radially arranged between recess <NUM> and valve assembly <NUM>. In some embodiments, protrusion <NUM> engages shoulder <NUM>. Shoulder <NUM> engages spring <NUM> to bias the electromagnet portion of fuel pump <NUM> in axial direction AD1. For example, spring <NUM> is arranged axially between shoulder <NUM> and pole <NUM> to maintain the proper positioning of coil bobbin <NUM>, coil <NUM>, pole <NUM>, and pole <NUM> in housing chamber <NUM>. In some embodiments, cover <NUM> is injection molded.

To assemble fuel pump <NUM>, filter <NUM> is arranged on hub <NUM> and filter bowl <NUM> is connected to section <NUM>, for example, via threading <NUM> and threading <NUM>. Valve assembly <NUM> is positioned within fuel chamber <NUM> and housing chamber <NUM>. The solenoid coil assembly, namely, coil bobbin <NUM>, coil <NUM>, pole <NUM>, pole <NUM>, and sleeve <NUM> are arranged in housing chamber <NUM>, concentrically or radially around valve assembly <NUM>. Circuit <NUM> is arranged in housing chamber <NUM>, along with respective terminal(s) <NUM> and/or terminal(s) <NUM>. In some embodiments, circuit <NUM> engages retainer <NUM> of coil bobbin <NUM>. In some embodiments, spring <NUM> and shoulder <NUM> are arranged on valve assembly <NUM>. In some embodiments, all of the components within case <NUM> are then secured therein with epoxy. Then cover <NUM> is connected to case <NUM>. In some embodiments, when fuel pump <NUM> is fully assembled it is hermetically sealed.

The electromagnetic portion of the pump comprises coil bobbin <NUM>, coil <NUM> arranged circumferentially around coil bobbin <NUM>, pole <NUM> arranged on a first axial side of coil bobbin, pole <NUM> arranged on a second axial side of coil bobbin, and sleeve <NUM> arranged circumferentially around coil <NUM>. In some embodiments, coil bobbin <NUM> comprises a polymer and houses solenoid coil <NUM>. As is known in the art, a coil or solenoid or solenoid coil is a type of electromagnet the purpose of which is to generate a controlled magnetic field through a coil wound into a tightly packed helix. Thus, coil <NUM> is wound as a helix around coil bobbin <NUM>, and also plunger assembly <NUM>. When electric current is passed through coil <NUM>, a magnetic field is produced, which in the present disclosure, then displaces plunger assembly <NUM> in axial direction AD1 within fuel chamber tube <NUM> (i.e., plunger assembly <NUM> is slidably arranged in fuel chamber tube <NUM>). Since plunger assembly <NUM> comprises a magnetic metal (e.g., <NUM> stainless steel), it reacts to the magnetic field created by coil <NUM> (i.e., coil <NUM> creates a magnetic field which attracts, or opposes, the polarity of plunger assembly <NUM>, specifically tube <NUM>) as will be described in greater detail below. The poles <NUM> and <NUM>, and sleeve <NUM> completely surround coil <NUM> in order to further direct the magnetic field toward plunger assembly <NUM>. Specifically, pole <NUM> is a metal magnetic pole arranged axially adjacent to coil bobbin <NUM>, pole <NUM> is a metal magnetic pole arranged axially adjacent to coil bobbin <NUM>, and sleeve <NUM> is a metal magnetic sleeve arranged circumferentially around coil <NUM>. Coil <NUM> is connected to two or more terminals <NUM>. Terminals <NUM> are connected to circuit <NUM>. In some embodiments, and as shown in the figures, each end of coil <NUM> is connected to a respective terminal <NUM> by way of a small helical coil (see <FIG>). The ends of coil <NUM> extend out of coil bobbin <NUM>, through an aperture in pole <NUM>, and engage their respective terminals <NUM>. In some embodiments, coil bobbin <NUM> further comprises retainer <NUM> which extends therefrom in axial direction AD2. Retainer <NUM> extends through an aperture in pole <NUM> and engages an aperture in circuit <NUM> in order to further secure circuit <NUM> to coil bobbin <NUM> (in addition to the connection via terminals <NUM> and coil <NUM>).

Circuit <NUM> is arranged around valve assembly <NUM> within housing chamber <NUM>. In some embodiments, circuit <NUM> comprises a circuit board. Terminals <NUM> are connected to circuit <NUM>, for example, via solder. In some embodiments, circuit <NUM> comprises one or more terminals <NUM>. For example, circuit <NUM> may have three connector terminals <NUM>, with two of the three terminals being used to supply electricity to circuit <NUM> and coil <NUM>, and the third terminal being used to supply a signal to circuit <NUM> from an external signal source to externally control when and for how long current is supplied to circuit <NUM> (i.e., without the use of or in addition to a microcontroller). Terminals <NUM> are connected to circuit <NUM>, for example, via solder, and are aligned with connector port <NUM>. Terminals <NUM> allow electrical connection with an external electrical connector via port <NUM>. In some embodiments, terminals <NUM>, circuit <NUM>, and terminals <NUM> (and their connection to an external signal source, provide electrical current to coil <NUM>. In some embodiments, circuit <NUM> comprises transistor <NUM>. In some embodiments, transistor <NUM> connects the circuit to ground thereby allowing current to run through coil <NUM>. In some embodiments, circuit <NUM> further comprises one or more microcontrollers. The microcontroller is operatively arranged to control circuit timing, for example, how long and when current is provided to coil <NUM>. The microcontroller may also control the amount of voltage provided to coil <NUM>. For example, the purpose of coil <NUM> and circuit <NUM> is to displace plunger assembly <NUM> with enough axial distance in order to pump a proper amount of fuel. To do this, there are two variables that might be considered: <NUM>) the amount of time current is provided to coil <NUM> and <NUM>) the amount of voltage provided to coil <NUM>. For example, if a large amount of voltage is applied to coil <NUM>, a large magnetic field will be produced and displace plunger assembly <NUM> a sufficient distance in a very short amount of time. If a low amount of voltage is applied to coil <NUM>, the same sufficient displacement distance of plunger assembly <NUM> may still be achieved but will require that current be provided to coil <NUM> for a longer amount of time. The microcontroller is programmed to control these variables based on the provided voltage levels. In some embodiments, the microcontroller shuts down coil <NUM> (i.e., stops voltage applied to coil <NUM>) if the input voltage exceeds a predetermined amount, for example, <NUM> Volts. As shown in the drawings, and specifically <FIG>, coil bobbin <NUM>, coil <NUM>, poles <NUM> and <NUM>, sleeve, circuit <NUM>, spring <NUM>, and shoulder <NUM> are all arranged concentrically around valve assembly <NUM> (i.e., valve assembly <NUM> runs through, for example apertures in, each of coil bobbin <NUM>, coil <NUM>, poles <NUM> and <NUM>, sleeve, circuit <NUM>, spring <NUM>, and shoulder <NUM>).

Fuel enters fuel pump <NUM> through inlet <NUM> and enters space or chamber <NUM>. The fuel then exits space <NUM> in axial direction AD1 and follows flow path FP1 through filter <NUM> (i.e., radially inward). Fuel then enters fuel chamber <NUM>, specifically fuel chamber <NUM> of valve assembly <NUM>, through hole <NUM> in section <NUM>, in axial direction AD2. Fuel travels in axial direction AD2 through valve assembly <NUM> and exits fuel pump <NUM> through outlet <NUM>. The displacement of fuel through valve assembly <NUM> will be described in greater detail below.

<FIG> is a perspective view of valve assembly <NUM>. <FIG> is a cross-sectional view of valve assembly <NUM> taken generally along line <NUM>-<NUM> in <FIG>. <FIG> is an exploded perspective view of valve assembly <NUM>. <FIG> is a detailed view of valve assembly <NUM> taken generally along detail <NUM> in <FIG>. Valve assembly <NUM> generally comprises fuel chamber tube <NUM>, check valve assembly <NUM>, spring <NUM>, plunger assembly <NUM>, and spring <NUM>. The following description should be read in view of <FIG>.

Check valve assembly <NUM> is operatively arranged to selectively allow fuel to flow into fuel chamber <NUM> in axial direction AD1. Check valve assembly <NUM> is arranged at a first end of fuel chamber tube <NUM> and comprises seat <NUM>, seal <NUM>, check valve <NUM>, spring <NUM>, and component <NUM>. Seat <NUM> comprises first axial side 102A and second axial side 102B. Seal <NUM> engages both axial sides of seat <NUM>. Specifically, and as shown in <FIG>, seal <NUM> is arranged adjacent to side 102A, wraps around a radially inward facing surface (through-bore) of seat <NUM>, and is also arranged adjacent to side 102B. As such, seal <NUM> provides sealing engagement of seat <NUM> with section <NUM> of case <NUM>, as well as sealing engagement of check valve <NUM>, specifically surface 106A, with seat <NUM>. Check valve <NUM> is operatively arranged to displace in axial direction AD1 and axial direction AD2 to allow passage of fuel into fuel chamber <NUM>, as indicated by flow path FP2. Check valve <NUM> comprises surface 106A, which is operatively arranged to sealing engage with surface 102B via seal <NUM>, and protrusion <NUM>, which is operatively arranged to engage spring <NUM>. Spring <NUM> biases check valve <NUM> into sealing engagement with seat <NUM>. Component <NUM> engages spring <NUM>. In some embodiments, spring <NUM> wraps concentrically around protrusion <NUM> and sits within an indentation in component <NUM>. Component <NUM> and spring <NUM> work together to bias check valve <NUM> in axial direction AD1. In some embodiments, component <NUM> is connected to seat <NUM>. Component <NUM> has a plurality of fingers that connect to seat <NUM> and allow for fluid to flow through component <NUM> in axial direction AD2. Spring <NUM> engages component <NUM> at a first end and seat <NUM> at a second end. Spring <NUM> is operatively arranged to bias plunger assembly <NUM> is axial direction AD2, as will be described in greater detail below. In some embodiments, spring <NUM> is frusto-conical. In some embodiments, spring <NUM> is a constant diameter helical spring.

Plunger assembly <NUM> is operatively arranged to selectively allow fuel to flow into through-bore <NUM> in axial direction AD1. Plunger assembly <NUM> is arranged at a second end of fuel chamber tube <NUM>, opposite check valve assembly <NUM>, and comprises tube <NUM>, seat <NUM>, component <NUM>, plunger <NUM>, and spring <NUM>. As previously described, plunger assembly <NUM>, specifically tube <NUM>, comprises a magnetic metal (e.g., <NUM> stainless steel) that displaces relative to the magnetic field created by coil <NUM>. Tube <NUM> comprises through-bore <NUM>, seat <NUM>, and seat <NUM>. Seat <NUM> has a cylindrical portion and flange portion that extend radially inward from the cylindrical portion on a first end of the cylindrical portion. The second end of the cylindrical portion engages seat <NUM>. In some embodiments, seat <NUM> is generally shaped like a brake drum of an automobile. Seat <NUM> comprises surface <NUM> which is arranged to engage plunger <NUM> to create a seal therebetween. Component <NUM> is arranged to engage seat <NUM>. As shown in <FIG>, component <NUM> is triangular shaped having a through-bore and curved radially outward facing surface apertures therein. Plunger <NUM> is generally arranged between seat <NUM> and component <NUM> and is connected to shaft <NUM> which is engaged with the through-bore of component <NUM>. In a sealed state, plunger <NUM> is engaged with surface <NUM>, thereby preventing fuel from entering through-bore <NUM> from fuel chamber <NUM>. In an unsealed state, plunger <NUM> displaces away from surface <NUM> in axial direction AD2 with respect to seat <NUM> and component <NUM>, thereby allowing fuel to flow through seat <NUM> and component <NUM> into through-bore <NUM>, as indicated by flow path FP3 in <FIG>. In some embodiments, a spring is arranged between component <NUM> and plunger <NUM> to bias plunger <NUM> into engagement with surface <NUM>. Spring <NUM> is arranged to engage seat <NUM> at a first end, and recess <NUM> of cover <NUM> at a second end. Spring <NUM> is arranged to dampen the return displacement of tube <NUM>. For example, when current provided to coil <NUM> is turned off, spring <NUM> displaces tube <NUM> in axial direction AD2. Spring <NUM> provides a buffer between tube <NUM> and cover <NUM>, thereby preventing tube <NUM> from impacting the solid material of cover <NUM> and possibly damaging it.

Claim 1:
A fuel pump (<NUM>), comprising:
a case (<NUM>), including:
a first section (<NUM>) comprising a hub (<NUM>) and a hole (<NUM>);
a second section (<NUM>), the second section (<NUM>) comprising a threading (<NUM>) and circumferentially arranged around the first section (<NUM>), wherein a radial space (<NUM>) is arranged between the first section (<NUM>) and the second section (<NUM>);
an inlet (<NUM>) in fluid communication with the radial space (<NUM>);
a housing chamber (<NUM>) arranged adjacent to the first section (<NUM>); and,
an outlet (<NUM>) in fluid communication with the hole (<NUM>);
a filter bowl (<NUM>) removably connected to the second section (<NUM>), the filter bowl (<NUM>) disposed outside the case (<NUM>) and providing a fuel path (FP1) outside the case (<NUM>), the filter bowl (<NUM>) fluidly connecting the radial space (<NUM>) with the hole (<NUM>) and axially extended from the second section (<NUM>);
a filter (<NUM>) engaged with the hub (<NUM>), the filter (<NUM>) partially arranged in the filter bowl (<NUM>) and positioned slidably and circumferentially around the hub (<NUM>);
a valve assembly (<NUM>) arranged at least partially in the first section (<NUM>) and at least partially in the housing chamber (<NUM>);
a coil (<NUM>) operatively arranged to apply a magnetic field to the valve assembly (<NUM>) to selectively displace fluid therethrough; and
a circuit (<NUM>) connected to the coil (<NUM>), wherein the circuit (<NUM>) includes a microcontroller operatively arranged to control current supplied to the coil (<NUM>).