Internal gear pump

Abstract

An internal gear pump is a return feed pump for a hydraulic vehicle braking system. The internal gear pump includes a filling part formed by two flexible sheet metal parts connected by an axial sealing element that is vulcanized in place and, in side view, is U-shaped. The axial sealing element is configured to improve the efficiency of the internal gear pump and allows large production tolerances.

1 . An internal gear pump, comprising:
 an internally toothed annulus;   an externally toothed pinion arranged eccentrically in the annulus and configured to mesh with the annulus in one section of a circumference;   a crescent-shaped free space between the pinion and the annulus opposite said one section of the circumference in which the pinion meshes with the annulus; and   a filler piece arranged in the free space, and having an inner part and an outer part,   wherein the inner part has an inner side on which tooth tips of teeth of the pinion rest,   wherein the outer part has an outer side on which tooth tips of teeth of the annulus rest, and   wherein an axial sealing element is arranged between the inner part and the outer part.   
     
     
         2 . The internal gear pump as claimed in  claim 1 , wherein one of the inner part and the outer part of the filler piece is a bent sheet metal part. 
     
     
         3 . The internal gear pump as claimed in  claim 1 , wherein the axial sealing element is configured to press the inner part of the filler piece elastically inward against the tooth tips of the teeth of the pinion and is configured to press the outer part of the filler piece elastically outward against the tooth tips of the teeth of the annulus. 
     
     
         4 . The internal gear pump as claimed in  claim 1 , wherein the axial sealing element has a cavity configured to communicate with a pressure side of the internal gear pump. 
     
     
         5 . The internal gear pump as claimed in  claim 4 , wherein:
 the axial sealing element is U-shaped and is closed at an end facing a suction side of the filler piece, and   the axial sealing element includes a first leg along an inner side of the outer part of the filler piece and includes a second leg along an outer side of the inner part of the filler piece.   
     
     
         6 . The internal gear pump as claimed in  claim 1 , wherein the axial sealing element is connected to the inner part and to the outer part of the filler piece. 
     
     
         7 . The internal gear pump as claimed in  claim 6 , wherein the inner part and the outer part of the filler piece are shaping elements during production of the axial sealing element. 
     
     
         8 . The internal gear pump as claimed in  claim 1 , further comprising a pressure-side abutment for the filler piece. 
     
     
         9 . The internal gear pump as claimed in  claim 8 , further comprising an axial plate including the pressure-side abutment for the filler piece. 
     
     
         10 . The internal gear pump as claimed in  claim 9 , wherein the pressure-side abutment is made by forming. 
     
     
         11 . The internal gear pump as claimed in  claim 1 , wherein the gear pump is for a hydraulic vehicle brake system.