High-pressure fuel pump and seal system for high-pressure fuel pump

A fuel pump comprising:

• a plunger reciprocating within the pump;
• a housing having the plunger passing therethrough;
• and
• a seal system for separating fuel and lubricating oil, the seal system being located adjacent the plunger reciprocating within the pump and the housing having the plunger passing therethrough,
• the seal system including:
• a first seal mounting part provided on an inner periphery of the housing at a fuel side of the housing, the first seal mounting part being recessed;
• a fuel-side seal mounted in the first seal mounting part at the fuel side for sealing fuel;
• a second seal mounting part provided at the lubricating oil side of the housing;
• and
• a lubricating-oil-side seal mounted to the second seal mounting part at the lubricating oil side for sealing lubricating oil,
• the fuel-side seal including:
• a plastic seal ring;
• and
• an elastomeric O ring adjacent the plastic seal ring, the lubricating-oil-side seal being a single body of a single-lip oil seal including:
• a metal ring;
• and
• an elastomeric seal lip fitted to the metal ring and arranged in a direction to seal lubricating oil, and
• wherein a distance between the fuel-side seal and the lubricating-oil-side seal is larger than a reciprocating motion distance of the plunger;
• wherein the second seal mounting part is provided on an outer periphery of the housing;
• wherein a washer is provided at the fuel side of the fuel-side seal;
• and
• the washer includes a diameter directional groove on one surface thereof.