High pressure fuel pump

Abstract

An axial plunger pump according to the present invention is constructed so as to comprise a shaft having a swash plate effecting swing motion and transmitting driving force from the outside, plungers each reciprocating by the swing motion of the swash plate, a cylinder block having cylinders formed so as to open on the side of the swash plate and inserting therein the plungers and having passages for supplying fuel to the cylinders, a body combined with the cylinder block to enclose the swash plate, and sealing members arranged between the plungers and the cylinders on the swash plate side of the passages formed in the cylinder block for sealing gaps between the plungers and the cylinders, respectively.

What is claimed is:  
     
         1 . A high pressure fuel pump comprising: 
 a shaft having an swash plate effecting swing motion, and transmitting driving force from the outside;    plungers each reciprocating by the swing motion of said swash plate;    a cylinder block having cylinders formed therein so as to open on the side of said swash plate and inserting therein said plungers, said cylinder block having passages for supplying fuel to said cylinders;    a body combined with said cylinder block to enclose said swash plate; and    sealing members arranged between said plungers and said cylinders for sealing gaps between said plungers and said cylinders, respectively, said sealing members being axially separated from said passages toward said swash plate.    
     
     
         2 . A high pressure fuel pump according to  claim 1 , 
 wherein fuel is supplied to pump chambers formed by said plungers and said cylinders, respectively.    
     
     
         3 . A high pressure fuel pump according to  claim 1 , wherein said pump comprises: 
 pump chambers formed by said plungers and said cylinders;    passages arranged inside said plungers for communicating between said passages for supplying fuel to said cylinders and said pump chambers;    grooves arranged inside said plungers so that said passages arranged inside said plungers are always communicating with said passage for supplying fuel to said said cylinders; and    valves for partitioning said pump chambers and said passages arranged inside said plungers, said valves allowing communication between said pump chambers and said passages arranged inside said plungers when fuel is a first pressure or higher; and    wherein fuel is supplied to said pump chambers through said plungers.    
     
     
         4 . A high pressure fuel pump according to  claim 1 , 
 wherein said pump comprises:    an oil chamber enclosed by said body for lubricating the swash plate side of said sealing members; and    a hole provided in said body for introducing oil on the engine side into said oil chamber.    
     
     
         5 . A high pressure fuel pump comprising: 
 a shaft having an swash plate effecting swing motion, and transmitting driving force from the outside;    plungers each reciprocating by the swing motion of said swash plate;    a cylinder block having cylinders formed so as to open on the side of said swash plate and inserting therein said plungers, said cylinder block having passages for supplying fuel to said cylinders;    a body combined with said cylinder block to enclose said swash plate;    a radial bearing supporting said shaft mounted on said body and    a bearing arranged on the back of said swash plate for supporting an axial load applied on said swash plate, said bearing being a thrust roll bearing having rolls or balls larger in rolling pitch diameter than said radial bearing.    
     
     
         6 . A high pressure fuel pump according to  claim 5 , 
 wherein a gap for inflow and/or outflow of oil is provided between said shaft and said radial bearing.    
     
     
         7 . A plunger for a high pressure fuel pump, having: 
 a radial hole traversing the central axis of said plunger;    a groove formed on the periphery so as to overlap with said radial hole and having a prescribed axial length;    an end portion to which an axial hole communicating with said radial hole is opened; and    the other end portion formed spherical.