Fuel sending unit assembly and operation

A fuel pump, comprising:

• a power group including a housing, a coil, a pole piece and an armature, the coil, pole piece and armature are disposed within the housing, the armature being movable within the housing;
• a valve group including a valve body, a plunger connected to the armature so as to be movable therewith, a bushing in which the plunger is at least partly disposed, an inlet chamber, an outlet chamber, a pump chamber, an inlet valve disposed between the inlet chamber and the pump chamber and an outlet valve disposed between the pump chamber and the outlet chamber, the outlet valve comprising a valve seat;
• and
• an inlet filter coupled to a fluid inlet of the valve group, wherein the inlet filter is disposed relative to the coil such that when the fuel pump is disposed within a fuel tank, a bottom of the inlet filter, as oriented in the fuel tank, is disposed above a fuel level in the fuel tank while the coil is at least partly submerged in the fuel,
• wherein the valve seat includes a disk member and a seat ring disposed along and extending from the disk member, the seat ring defining at least part of an outer wall of the inlet chamber, and the valve group further comprises a stop wire disposed at least partly around the seat ring.

A fuel pump, comprising:

• a power group including a housing, a coil, a pole piece and an armature, the coil, pole piece and armature are disposed within the housing, the armature being movable within the housing;
• a valve group including a valve body, a plunger connected to the armature so as to be movable therewith, a bushing in which the plunger is at least partly disposed, an inlet chamber, an outlet chamber, a pump chamber, an inlet valve disposed between the inlet chamber and the pump chamber and an outlet valve disposed between the pump chamber and the outlet valve;
• and
• an inlet filter coupled to a fluid inlet of the valve group, wherein the inlet filter is disposed relative to the coil such that when the fuel pump is disposed within a fuel tank, a bottom of the inlet filter, as oriented in the fuel tank, is disposed above a fuel level in the fuel tank while the coil is at least partly submerged in the fuel,
• wherein the valve group and the power group include a first fuel flow path from the pump chamber to outside the housing of the power group, including between an inner diameter of the bushing and an outer diameter of the plunger, and between an inner diameter of the housing and an outer diameter of the coil, the first fuel path passing fuel under pressure from the pump chamber to the power group during a downstroke of the armature and the plunger so that fuel pressure within the power group is positive during operation of the fuel pump.

A fuel pump, comprising:

• a power group including a housing, a coil, a pole piece and an armature, the coil, pole piece and armature are disposed within the housing, the armature being movable within the housing;
• and
• a valve group including a valve body, a plunger connected to the armature so as to be movable therewith, a bushing in which the plunger is at least partly disposed, an inlet chamber, an outlet chamber, a pump chamber, an inlet valve disposed between the inlet chamber and the pump chamber and an outlet valve disposed between the pump chamber and the outlet chamber,
• wherein the outlet valve comprises a valve seat, an outlet disk, and an outlet spring all disposed within the valve body, the outlet spring biases the outlet disk towards the valve seat, and a longitudinal axis of the outlet spring is offset from a longitudinal axis of the outlet disk, and
• wherein the valve group and the power group include a first fuel flow path from the pump chamber to outside the housing of the power group, including between an inner diameter of the bushing and an outer diameter of the plunger, and between an inner diameter of the housing and the outer diameter of the coil, the first fuel path passing fuel under pressure from the pump chamber to the power group during a downstroke of the armature and the plunger so that fuel pressure within the power group is positive during operation of the fuel pump.

A fuel pump, comprising:

• a power group including a housing, a coil, a pole piece and an armature, the coil, pole piece and armature are disposed within the housing, the armature being movable within the housing;
• and
• a valve group including a valve body, a plunger connected to the armature so as to be movable therewith, a bushing in which the plunger is at least partly disposed, an inlet chamber, an outlet chamber, a pump chamber, an inlet valve disposed between the inlet chamber and the pump chamber and an outlet valve disposed between the pump chamber and the outlet chamber,
• wherein the outlet valve comprises a valve seat, an outlet disk, and an outlet spring all disposed within the valve body, the outlet spring biases the outlet disk towards the valve seat, and a longitudinal axis of the outlet spring is offset from a longitudinal axis of the outlet disk, and
• wherein the valve seat includes a disk and a seat ring disposed along and extending from the disk, the seat ring defining at least part of an outer wall of the inlet chamber, the valve group further comprises a stop wire disposed at least partly around the seat ring, the stop wire has an annular shape with a gap defined in the stop wire, the gap providing a path for trapped air bubbles disposed outside of the seat ring to enter the pump chamber when the fuel pump is disposed in a fuel tank, for exiting the valve body through the outlet valve.