Sealing device

Abstract

A high performance sealing device ( 1 ) having an excellent pressure resistance, usable at a working pressure of 0 to 2 MPa, and not damaged even if the pressure of high-pressure fuel of 5 MPa or higher is applied thereto, wherein high pressure fuel on the high pressure side (H) is sealed by a first seal part ( 2 ), oil from a cam side on a low pressure side (L) is sealed by a second seal part ( 3 ), and the fuel slightly leaked through the first seal part ( 2 ) is sealed by the second seal part ( 3 ) to form a double seal structure, and a resin ring ( 21 ) slidably and sealingly coming into contact with a shaft ( 10 ) is used in the first seal part ( 2 ), whereby abnormal wear does not occur even if fuel with poor lubrication is used, and the durability of the seal is increased.

1 . (after amendment) a sealing device for sealing an annular gap formed between a reciprocating shaft and a housing in a fuel pump characterized by comprising: a first sealing part including a resin sealing member coming into slidable sealing contact with the surface of the shaft, and an urging member for urging the resin sealing member toward the surface of the shaft, the first sealing part sealing the side to be sealed where fuel exists, and 
 a second sealing part disposed on the side of the first sealing part opposite from the side to be sealed for sealing fuel depressurized at the first sealing part:    
     
     
         2 . A sealing device according to  claim 1 , characterized by comprising a seal retaining member forming a side wall of a groove on the side of the mounting groove for accommodating the first sealing part fitted therein opposite from the side to be sealed, 
 wherein the seal retaining member is formed with a second mounting groove for accommodating the second sealing part.    
     
     
         3 . A sealing device according to  claim 1  or  2 , characterized in that the second sealing part is a squeeze packing.  
     
     
         4 . (after amendment) A sealing device according to  claim 1  or  claim 2 , characterized in that the second sealing part comprises a resin sealing member coming into slidable sealing contact with the surface of the shaft, and an urging member for urging the resin sealing member toward the surface of the shaft.  
     
     
         5 . A sealing device according to  claim 1 , characterized in that the second sealing part is a packing having a back-pressure leaking capability.  
     
     
         6 . (After amendment) A sealing device according to  claim 1 , characterized in that the second sealing part is a sealing member having a seal lip portion coming into slidable sealing contact with the surface of the shaft.