High pressure fuel pump having a bellows sealing arrangement

Abstract

There is provided a high pressure fuel pump which includes a reliable fuel seal having a long durability and which can be produced at a relatively low cost. When a rotating shaft 4 is rotated to rotate a swash plate 7, such rotation is transmitted to a piston shoe guide plate 8 through a thrust ball bearing 9. Since the plate 8 is supported by a spherical portion 16 of a rod 14 mounted to a body 12, the plate 8 performs a precession to recurrently operate a plurality of fuel pumps 21 to 25 disposed around the rod 14. Each of the fuel pumps 21 to 25 includes a bellows provided between an outer end of the piston and the body 12, and the bellows completely seals a fuel leaked from a sliding clearance between the piston and the cylinder. Since the leaked fuel is introduced into a return passage 19 through a groove formed in an outer wall of the cylinder, a large internal pressure is not applied to the bellows and therefore, the bellows can be made of a low-priced material such as Teflon.

Dependencies are inferred from the claim text.