Fuel pump with independent plunger cover and seal

A fuel pump comprising:

• a barrel having a longitudinal axis that spans between a proximal end and a distal end, the barrel including a central bore along the longitudinal axis;
• a plunger disposed at least partially in the central bore, the plunger configured to move along the longitudinal axis;
• and
• an annular seal assembly arranged around the circumference of the plunger, the annular seal assembly including a seal retainer housing and a first seal, the proximal end of the barrel contained within the seal retainer housing such that the proximal end of the barrel forms a second seal with the seal retainer housing, the annular seal assembly is configured to be removed from the plunger and re-assembled with the plunger.

A fuel pump comprising:

• a barrel having a longitudinal axis that spans between a proximal end and a distal end, the barrel including a central bore along the longitudinal axis;
• a plunger disposed at least partially in the central bore, the plunger configured to move along the longitudinal axis;
• an annular seal assembly coupled to and disposed around:
• (i) a circumference of the proximal end of the barrel to contain the proximal end of the barrel within the annular seal assembly, and
• (ii) a circumference of the plunger,
• to prevent mixing of fuel and oil;
• a first coil spring having a proximal end opposite a distal end, wherein the proximal end is assembled with the plunger and the distal end is in contact with the annular seal assembly to urge the annular seal assembly towards the barrel;
• and
• a second coil spring having a proximal end opposite a distal end, wherein the distal end is retained on the barrel and the proximal end is in contact with a tappet assembly.