Gear Pump

Abstract

A gear pump is described with a plurality of gear wheels which intermesh in order to deliver a pumping medium, and are rotatably held in a pump case and deliver a pumping medium from a priming zone into a delivery pressure zone of the pump case. One of the gear wheels is driven by a pump shaft which protrudes with a coupling end out of the pump case. In order to seal the pump case, a shaft sealing ring is held around the circumference of the pump shaft, wherein according to the invention, in order to avoid material deposits, the shaft sealing ring is associated with an interior flushing chamber on the circumference of the pump shaft, the flushing chamber being connected to the delivery pressure zone of the pump case by a feed channel in the pump case.

1 . A gear pump comprising:
 a plurality of intermeshed gear wheels that are rotatably held in a pump housing to deliver a pumping medium from a priming zone into a delivery pressure zone of the pump housing;   a pump shaft for driving one of the gear wheels, wherein the pump shaft has a coupling end protruding from the pump housing and a shaft sealing ring held on the circumference of the pump shaft for sealing the pump housing; and   an interior flushing chamber about the circumference of the pump shaft and associated with the shaft sealing ring, the flushing chamber being connected to the delivery pressure zone of the pump housing by a feed channel in the pump housing   
     
     
         2 . The gear pump according to Claim  1 , wherein the flushing chamber is in fluid communication with the priming zone of the pump housing by a return channel in the pump housing. 
     
     
         3 . The gear pump according to Claim  1 , wherein at least one of the feed channel and the return channel flow into a region of a stop face of a housing plate of the pump housing which cooperates on the front side with the gear wheel held on the pump shaft. 
     
     
         4 . The gear pump according to Claim  1 , wherein the feed channel and the return channel flow into the flushing chamber at an angular offset of 180°. 
     
     
         5 . The gear pump according to Claim  1 , wherein at least one of the feed channel and the return channel have a throttle. 
     
     
         6 . The gear pump according to  claim 5 , wherein the throttle is formed by a throttle bore in a filler ring, the filler ring being associated with the flushing chamber of one of a mouth of the feed channel and a mouth of the return channel. 
     
     
         7 . The gear pump according to  claim 5 , wherein the filler ring has two throttle bores facing one another wherein one is in fluid communication with the feed channel and the other is in fluid communication with the return channel. 
     
     
         8 . The gear pump according to Claim  1 , wherein the shaft sealing ring is held by a seal housing that is connected to the pump housing and penetrated by the pump shaft. 
     
     
         9 . The gear pump according to  claim 8 , wherein the seal housing has a centering collar forming the flushing chamber, said centering collar meshing in a centering section of the pump housing and fixedly holding the filler ring via a rotating brace. 
     
     
         10 . The gear pump according to  claim 8 , wherein a second shaft sealing ring is held within the seal housing and a separation chamber is constructed between the two shaft sealing rings on the circumference of the pump shaft.