Gear pump, in particular fuel pump

Abstract

A gear pump includes at least two gear wheels, which are disposed in a housing and mesh with one another and pump a fluid from a suction region to a compression region. At least one of the gear wheels includes tooth flanks, which each have at least one generally radially extending recess, which in the region in which the two gear wheels mesh with one another connects a fluid chamber, adjacent to the root region of the gear wheel, to a fluid chamber adjacent to the tip region of that gear wheel.

1 . In a gear pump ( 10 ), having a housing ( 24 ) and at least two gear wheels ( 28 ,  30 ) disposed in the housing ( 24 ) and meshing with one another to pump a fluid from a suction region ( 66 ) and a compression region ( 68 ) in the housing ( 24 ), the improvement wherein at least one of the gear wheels has tooth flanks ( 48 ), which each have at least one recess ( 56 ) that, in a region ( 70 ) in which the two gear wheels ( 28 ,  30 ) mesh with one another, connects a fluid chamber ( 76 ), adjoining the root region ( 60 ) of one gear wheel ( 30 ), to a fluid chamber ( 74 ) adjacent to the tip region ( 58 ) of that gear wheel.  
   
   
       2 . The gear pump ( 10 ) in accordance with  claim 1 , further comprising a spacing (A) is provided between one edge of the recess ( 56 ) and one edge of the tooth flank ( 48 ).  
   
   
       3 . The gear pump ( 10 ) in accordance with  claim 1 , further comprising a spacing (B) is provided between the radially outer end of the recess ( 56 ) and a tip circle ( 58 ) of the gear wheel ( 30 ).  
   
   
       4 . The gear pump ( 10 ) in accordance with  claim 2 , further comprising a spacing (B) is provided between the radially outer end of the recess ( 56 ) and a tip circle ( 58 ) of the gear wheel ( 30 ).  
   
   
       5 . The gear pump ( 10 ) in accordance with  claim 1 , wherein the recesses ( 56 ) include a lateral oblique flattened face, in particular a polished section ( 56 ).  
   
   
       6 . The gear pump ( 10 ) in accordance with  claim 2 , wherein the recesses ( 56 ) include a lateral oblique flattened face, in particular a polished section ( 56 ).  
   
   
       7 . The gear pump ( 10 ) in accordance with  claim 3 , wherein the recesses ( 56 ) include a lateral oblique flattened face, in particular a polished section ( 56 ).  
   
   
       8 . The gear pump ( 10 ) in accordance with  claim 4 , wherein the recesses ( 56 ) include a lateral oblique flattened face, in particular a polished section ( 56 ).  
   
   
       9 . The gear pump ( 10 ) in accordance with  claim 1 , wherein the recess ( 56 ) includes at least one flute or groove ( 56 ).  
   
   
       10 . The gear pump ( 10 ) in accordance with  claim 2 , wherein the recess ( 56 ) includes at least one flute or groove ( 56 ).  
   
   
       11 . The gear pump ( 10 ) in accordance with  claim 1 , wherein the recesses ( 56 ) are present only on the non-driving and/or non-driven tooth flanks ( 48 ) of a gear wheel ( 30 ).  
   
   
       12 . The gear pump ( 10 ) in accordance with  claim 2 , wherein the recesses ( 56 ) are present only on the non-driving and/or non-driven tooth flanks ( 48 ) of a gear wheel ( 30 ).  
   
   
       13 . The gear pump ( 10 ) in accordance with  claim 3 , wherein the recesses ( 56 ) are present only on the non-driving and/or non-driven tooth flanks ( 48 ) of a gear wheel ( 30 ).  
   
   
       14 . The gear pump ( 10 ) in accordance with  claim 5 , wherein the recesses ( 56 ) are present only on the non-driving and/or non-driven tooth flanks ( 48 ) of a gear wheel ( 30 ).  
   
   
       15 . The gear pump ( 10 ) in accordance with  claim 1 , wherein the recesses ( 56 ) are present only on the tooth flanks ( 48 ) of the driven gear wheel ( 30 ).  
   
   
       16 . The gear pump ( 10 ) in accordance with  claim 2 , wherein the recesses ( 56 ) are present only on the tooth flanks ( 48 ) of the driven gear wheel ( 30 ).  
   
   
       17 . The gear pump ( 10 ) in accordance with  claim 3 , wherein the recesses ( 56 ) are present only on the tooth flanks ( 48 ) of the driven gear wheel ( 30 ).  
   
   
       18 . The gear pump ( 10 ) in accordance with  claim 5 , wherein the recesses ( 56 ) are present only on the tooth flanks ( 48 ) of the driven gear wheel ( 30 ).  
   
   
       19 . The gear pump ( 10 ) in accordance with  claim 9 , wherein the recesses ( 56 ) are present only on the tooth flanks ( 48 ) of the driven gear wheel ( 30 ).  
   
   
       20 . The gear pump ( 10 ) in accordance with  claim 1 , wherein the gear wheels ( 28 ,  30 ) have a symmetrical tooth geometry, in particular a simple evolute toothing.