Filter Element and Filter System for a Liquid Medium, in Particular Diesel Fuel

Abstract

A filter element arranged in a filter housing is provided with an annular filter medium flowed through by a liquid medium in a flow direction radial to a longitudinal axis of the filter element. A clean chamber is arranged in the flow direction of the liquid medium downstream of the filter medium. A filtered liquid medium outlet is fluidically connected to the clean chamber. A cylinder-shaped water separating screen is arranged in the clean chamber to separate water contained in the liquid medium. A water outlet opening fluidically connects the clean chamber to a water collecting chamber of the filter housing. A particle filter is arranged at the water outlet opening or arranged between the water outlet opening and the filtered liquid medium outlet of the filter element. The water outlet opening of the filter element is fluidically connected with the water collecting chamber of the filter housing.

What is claimed is: 
     
         1 . A filter element for a liquid medium, the filter element comprising:
 an annular filter medium encircling a longitudinal axis and configured to be flowed through by the liquid medium in a flow direction radial to the longitudinal axis of the filter element, the annular filter medium having:
 an upper end plate; and 
 a bottom end plate comprising:
 a water outlet opening; 
 an annular projection surrounding the water outlet opening and projecting axially outwardly from an axially outer side of the bottom end plate; 
 an annular shoulder formed on the annular projection and surrounding the water outlet opening; 
 an annular locking member formed on the annular projection and projecting axially outwardly; 
 
 a particle filter of a hydrophilic fiber material and having a greater pore size than the annular filter medium of the filter element, the particle filter arranged at and covering the water outlet opening, the particle filter attached to the bottom end plate by the annular securing device that is locked onto or screwed into the bottom end plate; 
   a coalescing medium arranged on a radially inner side of the annular filter medium;   an assembly unit comprising:
 a screen element as a cylinder-shaped water separating screen having a closed bottom, an upper axial end of the cylinder-shaped water separating screen forming a radially outwardly extending flange, the cylinder-shaped water separating screen adapted to separate water contained in the liquid medium from the liquid medium; 
 wherein the radially outwardly extending flange is adapted to connect the assembly unit to a housing cover of a filter system; 
 wherein the radially outwardly extending flange of the cylinder-shaped water separating screen rests directly on an axially outer face of the upper end plate; 
 a clean chamber arranged at the radially inner side of the screen element, and closed at a lower end of the clean chamber by the closed bottom, the clean chamber arranged in the flow direction of the liquid medium downstream of annular the filter medium; and 
 wherein the assembly unit is configured for installation as a unit into an interior of the annular filter medium. 
   
     
     
         2 . The filter element according to  claim 1 , wherein
 the bottom end plate further comprises:
 an annular projection surrounding the water outlet opening and projecting axially outwardly from an axially outer side of the bottom end plate; 
 an annular shoulder formed on the annular projection and surrounding the water outlet opening; and 
 an annular locking member formed on the annular projection and projecting axially outwardly; and 
   wherein the particle filter further comprises:
 an annular securing device received onto and engaging the with the annular locking member of the bottom end disk; and 
 wherein the particle filter is arranged on the annular shoulder between the bottom end plate and the annular securing device, the engagement of the annular securing device and the annular locking member securing the particle filter covering the water outlet opening. 
   
     
     
         3 . The filter element according to  claim 1 , wherein
 the particle filter is star-folded.   
     
     
         4 . The filter element according to  claim 1 , wherein
 the particle filter comprises fibers with a unidirectional or substantially unidirectional fiber extension.   
     
     
         5 . The filter element according to  claim 1 , wherein
 the coalescing medium is arranged at a radial spacing away from the cylinder-shaped water separating screen, forming a separating chamber there between;   wherein separated water moves downwards in the separating chamber to be collected in a water collection chamber.   
     
     
         6 . The filter element according to  claim 1 , further comprising:
 a rubber elastic seal ring arranged on a radially outer circumferential side of the bottom end disk;   wherein the rubber elastic seal ring is adapted to seal between the bottom end disk and a filter housing configured to receive the filter element.   
     
     
         7 . A filter system comprising:
 a filter housing having an integral chamber and a water collecting chamber; and   a filter element arranged in the internal chamber of the filter housing, the filter element comprising:
 an annular filter medium encircling a longitudinal axis and configured to be flowed through by the liquid medium in a flow direction radial to the longitudinal axis of the filter element, the annular filter medium having:
 an upper end plate; and 
 a bottom end plate comprising:
 a water outlet opening; 
 an annular projection surrounding the water outlet opening and projecting axially outwardly from an axially outer side of the bottom end plate; 
 an annular shoulder formed on the annular projection and surrounding the water outlet opening; 
 an annular locking member formed on the annular projection and projecting axially outwardly; 
 
 a particle filter of a hydrophilic fiber material and having a greater pore size than the annular filter medium of the filter element, the particle filter arranged at and covering the water outlet opening, the particle filter attached to the bottom end plate by the annular securing device that is locked onto or screwed into the bottom end plate; 
 
 a coalescing medium arranged on a radially inner side of the annular filter medium; 
 an assembly unit comprising:
 a screen element as a cylinder-shaped water separating screen having a closed bottom, an upper axial end of the cylinder-shaped water separating screen forming a radially outwardly extending flange, the cylinder-shaped water separating screen adapted to separate water contained in the liquid medium from the liquid medium; 
 wherein the radially outwardly extending flange is adapted to connect the assembly unit to a housing cover of a filter system; 
 wherein the radially outwardly extending flange of the cylinder-shaped water separating screen rests directly on an axially outer face of the upper end plate; 
 a clean chamber arranged at the radially inner side of the screen element, and closed at a lower end of the clean chamber by the closed bottom, the clean chamber arranged in the flow direction of the liquid medium downstream of annular the filter medium; and 
 wherein the assembly unit is configured for installation as a unit into an interior of the annular filter medium. 
 
   
     
     
         8 . The filter system according to  claim 7 , wherein
 the bottom end plate further comprises:
 an annular projection surrounding the water outlet opening and projecting axially outwardly from an axially outer side of the bottom end plate; 
 an annular shoulder formed on the annular projection and surrounding the water outlet opening; and 
 an annular locking member formed on the annular projection and projecting axially outwardly; and 
   wherein the particle filter further comprises:
 an annular securing device received onto and engaging the with the annular locking member of the bottom end disk; and 
 wherein the particle filter is arranged on the annular shoulder between the bottom end plate and the annular securing device, the engagement of the annular securing device and the annular locking member securing the particle filter covering the water outlet opening. 
   
     
     
         9 . The filter system according to  claim 7 , wherein
 the particle filter is star-folded.   
     
     
         10 . The filter system according to  claim 7 , wherein
 the particle filter comprises fibers with a unidirectional or substantially unidirectional fiber extension.   
     
     
         11 . The filter system according to  claim 7 , wherein
 the coalescing medium is arranged at a radial spacing away from the cylinder-shaped water separating screen, forming a separating chamber there between;   wherein separated water moves downwards in the separating chamber to be collected in the water collection chamber in the filter housing.   
     
     
         12 . The filter system according to  claim 7 , further comprising:
 a rubber elastic seal ring arranged on a radially outer circumferential side of the bottom end disk;   wherein the rubber elastic seal ring is seals between the bottom end disk and the filter housing.