Dry sump lubrication system for centrifugal pumps

Abstract

A lubrication system is provided for a centrifugal pump of the type having a bearing housing for maintaining the lubrication of a plurality of pump shaft rolling element bearings. The system includes a lubricant reservoir forming a volume, and having at least one supply port for supplying lubricant to the bearing housing, and at least one return port for returning lubricant to the lubricant reservoir. A lubricant recirculation pump has at least one supply stage and at least one suction stage. A connector is provided between the supply port of the reservoir and the suction stage of the lubricant recirculation pump for the supply of lubricant to the suction stage of the recirculation pump. A connector is also provided for interconnecting the supply stage of the lubricant recirculation pump to the bearing housing for the delivery of lubricant to the bearing housing. Lastly, a connector is provided for interconnecting the bearing housing and the at least one suction stage of the lubricant recirculation pump for the return of lubricant to the lubricant recirculation pump.

1 . A lubrication system for a centrifugal pump of the type having a bearing housing for maintaining the lubrication of a plurality of pump shaft rolling element bearings, comprising:
 (a) a lubricant reservoir forming a volume, and having at least one supply port for supplying lubricant to the bearing housing, and at least one return port for returning lubricant to the lubricant reservoir;   (b) a lubricant recirculation pump having at least one supply stage and at least one suction stage;   (c) a connector between the supply port of the reservoir and the suction stage of the lubricant recirculation pump for the supply of lubricant to the suction stage of the recirculation pump;   (d) a connector for interconnecting the supply stage of the lubricant recirculation pump to the bearing housing for the delivery of lubricant to the bearing housing; and   (e) a connector for interconnecting the bearing housing and the at least one suction stage of the lubricant recirculation pump for the return of lubricant to the lubricant recirculation pump.   
   
   
       2 . The lubrication system of  claim 1  wherein the lubricant reservoir is configured for mounting above the bearing housing. 
   
   
       3 . The lubrication system of  claim 1  wherein the lubricant reservoir further comprises at least one internal baffle, the internal baffle separating the volume of the reservoir into lubricant supply and lubricant return portions. 
   
   
       4 . The lubrication system of  claim 1  wherein the external lubricant reservoir further comprises an auxiliary lubrication mechanism, the mechanism comprising:
 (a) a check valve mounted at a predetermined height within the reservoir;   (b) a discharge port proximate the bottom of the reservoir; and   (c) wherein the check valve is configured to permit a predetermined quantity of lubricate to flow through the discharge port to the bearing housing.   
   
   
       5 . The lubrication system of  claim 1  wherein the external lubricant reservoir further comprises a pressure balancing air vent valve proximate the top of the reservoir, the pressure balancing air vent valve configured for interconnection with the bearing housing. 
   
   
       6 . The lubrication system of  claim 1  further comprising a supply manifold through which the supply stage of the lubricant recirculation pump delivers lubricant to the bearing housing. 
   
   
       7 . The lubrication system of  claim 6  wherein the supply manifold comprises a plurality of discharge branches configured for interconnection with bearing housing proximate each of the plurality of pump shaft rolling element bearings. 
   
   
       8 . The lubrication system of  claim 1  further comprising a lubricant filter positioned upstream of the return port of the reservoir. 
   
   
       9 . The lubrication system of  claim 1  wherein:
 (a) the multiple stage pump comprises at least two suction stages; and   (b) wherein a return line is configured to interconnect each of the at least two suction stages to the bearing housing for the return of lubricant from the bearing housing to the at least two suction stages.   
   
   
       10 . The lubrication system of  claim 9  wherein each of the return lines further interconnect to a scavenge hose, each scavenge hose configured to scavenge lubricant at spaced points within the bearing housing. 
   
   
       11 . A centrifugal pump, comprising:
 (a) a pump shaft rotatably supported by a plurality of rolling element bearings;   (b) a bearing housing for maintaining the lubrication of the plurality of pump shaft rolling element bearings;:   (c) a lubrication system, comprising:
 (i) a lubricant reservoir forming a volume, at least one supply port for supplying lubricant to the bearing housing, and at least one return port for returning lubricant to the lubricant reservoir; 
 (ii) a lubricant recirculation pump having at least one supply stage and at least one suction stage; 
 (iii) a connection between the supply port of the reservoir and the suction stage of the lubricant recirculation pump for the supply of lubricant to the suction stage of the recirculation pump; 
 (iv) a connection between the supply stage of the lubricant recirculation pump and the bearing housing for the delivery of lubricant to the bearing housing; and 
 (v) a connection between the bearing housing and the at least one suction stage of the lubricant recirculation pump for the return of lubricant to the lubricant recirculation pump. 
   
   
   
       12 . The lubrication system of  claim 11  wherein the lubricant reservoir is configured for mounting above the bearing housing. 
   
   
       13 . The pump of  claim 12  wherein the lubricant reservoir further comprises at least one internal baffle, the internal baffle separating the volume of the reservoir into lubricant supply and lubricant return portions. 
   
   
       14 . The pump of  claim 12  wherein the external lubricant reservoir further comprises an auxiliary lubrication mechanism, the mechanism comprising:
 (a) a check valve mounted at a predetermined height within the reservoir;   (b) a discharge port proximate the bottom of the reservoir; and   (c) wherein the check valve is configured to permit a predetermined quantity of lubricate to flow through the discharge port to the bearing housing.   
   
   
       15 . The pump of  claim 12  wherein the external lubricant reservoir further comprises a pressure balancing air vent valve proximate the top of the reservoir, the pressure balancing air vent valve interconnected to the bearing housing. 
   
   
       16 . The pump of  claim 12  further comprising a supply manifold through which the supply stage of the lubricant recirculation pump delivers lubricant to the bearing housing. 
   
   
       17 . The pump of  claim 16  wherein the supply manifold comprises a plurality of discharge branches interconnected to the bearing housing proximate each of the plurality of pump shaft rolling element bearings. 
   
   
       18 . The pump of  claim 12  further comprising a lubricant filter positioned upstream of the return port of the reservoir. 
   
   
       19 . The pump of  claim 12  wherein:
 (a) the multiple stage pump comprises at least two suction stages; and   (b) wherein a return line interconnects each of the at least two suction stages to the bearing housing for the return of lubricant from the bearing housing to the at least two suction stages.   
   
   
       20 . The pump of  claim 19  wherein each of the return lines further interconnect to a scavenge hose, each scavenge hose configured to scavenge lubricant at spaced points within the bearing housing.