HIGH-PRESSURE FUEL PUMP AND SEAL SYSTEM FOR HIGH-PRESSURE FUEL PUMP

摘要

A high-pressure fuel pump with seal system that is usable under the conditions of "high speed", "high pressure" and "fuel resistance". There is provided a high-pressure fuel pump comprising an axle capable of reciprocating motion in the pump and seal system (21) for separating/sealing of fuel and lubricating oil as sealing objects in a circular space within a housing having the axle passing therethrough, wherein the seal system (21) consists of a combination of fuel-side seal (31) for sealing of fuel and lubricating-oil-side seal (41) for sealing of lubricating oil. The fuel-side seal (31) is composed of plastic-made seal ring (32) and rubbery-elastomer-made O ring (33) for backup of the seal ring (32). The lubricating-oil-side seal (41) consists of a single body of single-lip-type oil seal (42) wherein rubbery-elastomer-made seal lip (44) fitted to metal ring (43) is arranged so as to face the lubricating oil side. The spacing between the fuel-side seal (31) and the lubricating-oil-side seal (41) is set so as to be larger than the reciprocating motion distance of the axle.