Patent ID: 8348639
Filing Date: 2013-01-08
Classification: F02M,F04B,F16J

Abstract:
1. A high pressure fuel pump for pressurizing fuel to a high pressure in an engine of an in-cylinder direct injection system, the fuel pump comprising a reciprocating shaft, a housing with an aperture, through which the shaft reciprocates, and a sealing device for sealing an annular gap formed between the reciprocating shaft and the housing, the sealing device comprising a first sealing part including a resin sealing member in slidable sealing contact with a surface of the shaft, and an O-ring urging member for urging the resin sealing member toward the surface of the shaft, the first sealing part sealing a side to be sealed where fuel exists, the resin sealing member being from a tetrafluoroethylene group, the O-ring urging member being one of fluorinated rubber and acrylic rubber, a second sealing part including a squeeze packing and a U-shaped seal retainer, said second sealing part being disposed on a side of the first sealing part opposite to the side to be sealed for sealing fuel depressurized at the first sealing part and lubrication oil which exists on the opposite side of where fuel exists, said squeeze packing being in slidable sealing contact with the surface of the shaft, said U-shaped seal retainer engaging the housing and being located between the housing and the shaft and extending towards the shaft, said U-shaped seal retainer forming a first mounting groove in conjunction with the housing, said first mounting groove receiving said first sealing part fitted therein, said U-shaped seal retainer forming a second mounting groove, said second mounting groove receiving said squeeze packing therein, and said squeeze packing being an X-ring, a distance between two lips of the X-ring coming into contact with the shaft being shorter than a reciprocating stroke of the shaft, the X-ring being one of fluorinated rubber and acrylic rubber, an axial distance between the first sealing part and the squeeze packing being longer than a reciprocating stroke of the shaft to prevent the fuel sealed by the first sealing part from entering the squeeze packing, said first sealing part and said second sealing part being located in a single cavity of the housing.