Rotary vane pump

Abstract

A rotary vane pump for delivering a fluid, having a rotary delivery device accommodated in a casing ( 2 ), a casing cover ( 3 ) arranged on one side of the casing and a bearing flange ( 4 ) on the opposite side. A suction zone ( 12 ) is formed on each of the sides, and an injector device ( 114 ) injects a pressurized fluid into the fluid as it is delivered toward each of the suction zones to thereby assure a uniform admission of the fluid into the cells of the rotary delivery device of the pump. Also a leakage path ( 13 ) for the fluid extends between the delivery zone ( 11 ) and suction zone ( 12 ). The leakage path ( 13 ) extends on the inner side ( 14 ) of the seal at least in sections parallel to the seal ( 5,6 ).

That which is claimed:  
     
         1 . A pump for delivering a fluid comprising 
 a casing which comprises an interior chamber, opposite sides, a suction zone on each of the sides, and a delivery zone on at least one of the sides,    a delivery device accommodated in the interior chamber of the casing for displacing a fluid from each of the suction zones to the delivery zone,    a jet chamber positioned on each side of the casing and communicating with the suction zone on the same side thereof,    a feed channel for delivering a fluid to the pump and including two subchannels communicating with respective ones of the jet chambers, and    an injector device for injecting a pressurized fluid into each of the two jet chambers so as to entrain the fluid which flows into the two jet chambers from the subchannel of the feed channel and convey the fluid toward the associated suction zone.    
     
     
         2 . The pump of  claim 1  wherein the injector device is positioned centrally between the two jet chambers and includes two nozzles which are oriented in opposite directions, so that the nozzles are directed toward respective ones of the two jet chambers.  
     
     
         3 . The pump of  claim 2  wherein the two nozzles are coaxially aligned.  
     
     
         4 . The pump of  claim 3  wherein the injector device is located centrally above the delivery device.  
     
     
         5 . The pump of  claim 2  wherein the two subchannels of the feed channel are oriented with respect to the two nozzles so that the fluid injected from the nozzles has a directional component which is parallel to the direction of the fluid entering the associated jet chamber from the associated subchannel.  
     
     
         6 . The pump of  claim 5  wherein the feed channel includes a common segment upstream of the two subchannels, and wherein the two subchannels have substantially the same length.  
     
     
         7 . The pump of  claim 6  wherein the two subchannels are substantially mirror images of each other.  
     
     
         8 . The pump of  claim 2  further comprising a cover overlying one side of the casing and a bearing flange overlying the other side of the casing, and wherein one of the jet chambers is integrally formed at least in part by the cover and the other jet chamber is integrally formed at least in part by the bearing flange.  
     
     
         9 . The pump of  claim 2  wherein the jet chambers each include a wall which is transverse to an injecting direction of the associated nozzle and to the direction in which the fluid enters from the associated subchannel.  
     
     
         10 . The pump of  claim 9  wherein the suction zone on each side of the casing comprises two separate suction chambers.  
     
     
         11 . The pump of  claim 10  wherein said transverse wall of each of the jet chambers is configured such that it divides the fluid impacting thereon approximately evenly and so as to cause the fluid to flow along suction channels to each of the associated suction chambers.  
     
     
         12 . The pump of  claim 11  wherein the suction channels on each side of the casing are of substantially equal length.  
     
     
         13 . The pump of  claim 9  wherein the two jet nozzles are obliquely inclined at an acute angle downwardly with respect to the associated wall and toward the associated suction zone.  
     
     
         14 . The pump of  claim 2  further comprising a pressure control pilot for returning high pressure fluid to the feed channel from the delivery zone.  
     
     
         15 . The pump of  claim 14  further comprising a channel for returning fluid which leaks from the delivery zone back to the feed channel.