Internal Gear Pump

Abstract

An internal gear pump comprises an internal gear, a pinion eccentrically positioned in the internal gear and configured to mesh with the internal gear, a cover configured to close an installation space of the internal gear pump, and positioned on end sides of the pinion and the internal gear, a pump outlet leading through the cover, and a non-return valve positioned in the pump outlet in the cover and configured to open to allow flow out of the internal gear pump, and further configured to shut to disallow a return flow through the pump outlet into the internal gear pump.

What is claimed is: 
     
         1 . An internal gear pump comprising:
 an internal gear;   a pinion eccentrically positioned in the internal gear and configured to mesh with the internal gear;   a cover configured to close an installation space of the internal gear pump, the cover positioned on end sides of the pinion and the internal gear;   a pump outlet defined through the cover; and   a non-return valve positioned in the pump outlet in the cover and configured to open to allow a fluid flow out of the internal gear pump, and further configured to shut to prevent a return fluid flow through the pump outlet into the internal gear pump.   
     
     
         2 . An internal gear pump according to  claim 1 , wherein:
 the cover defines a stepped hole; and   a valve seat of the non-return valve is defined on a step of the stepped hole.   
     
     
         3 . An internal gear pump according to  claim 1 , wherein the non-return valve includes a damper configured to damp pressure oscillations of fluid conveyed by the internal gear pump. 
     
     
         4 . An internal gear pump according to  claim 3 , wherein the non-return valve further includes at least one of an elastic damper body and a spring damper body. 
     
     
         5 . An internal gear pump according to  claim 3 , wherein the pump outlet in the cover has a through flow cross section configured to damp pressure oscillations of the fluid conveyed by the internal gear pump. 
     
     
         6 . An internal gear pump according to  claim 1 , further comprising:
 a filter positioned in the pump outlet in the cover,   wherein the filter is also positioned upstream, relative to a direction of fluid flowing out of the internal gear pump, of the non-return valve.   
     
     
         7 . An internal gear pump according to  claim 6 , further comprising:
 a rotationally fixed and axial movable axial washer positioned between, on one side, the pinion and the internal gear and, on another side, the cover,   wherein the internal gear pump is configured to develop a pressure field on an outer side facing away from the pinion and the internal gear, the pressure field forcing the axial washer, in the case of pressure loading, into bearing contact with the end sides of the pinion and the internal gear;   wherein the filter is positioned in the pressure field.   
     
     
         8 . An internal gear pump according to  claim 7 , further comprising:
 a pressure field seal configured to enclose the pressure field,   wherein the filter includes a supporting element configured to support the pressure field seal on an inside of the pressure field seal.   
     
     
         9 . An internal gear pump according to  claim 8 , wherein the filter and the supporting element are formed as one piece. 
     
     
         10 . An internal gear pump according to  claim 8 , wherein the filter includes a collar.