External gear and rotor hybrid pump

Abstract

Apparatuses and methods are provided for a hybrid gear-and-rotor pump. A pump includes a faceplate assembly, a backplate assembly, a main case with a chamber, and a hybrid gear-and-rotor assembly. The hybrid gear-and-rotor assembly includes a first shaft and a second shaft. The first and second shafts are configured to extend through the chamber into bores in the faceplate and backplate assemblies. The first shaft includes a first gear and a first rotor mounted for rotation on the first shaft within the chamber. The second shaft includes a second gear and a second rotor mounted for rotation on the second shaft within the chamber. The first gear is intermeshed with the second gear, and the first rotor is intermeshed with the second rotor, so as to transfer fluid from a suction port of the main case to the discharge port during rotation of the first and second shafts.

What is claimed is: 
     
         1 . A pump, comprising:
 a main case having a chamber including a suction port and a discharge port;   a faceplate assembly secured to a first side of the main case;   a backplate assembly secured to a second side of the main case;   a first shaft;   a second shaft, wherein the first shaft and the second shaft are configured to extend through the chamber into bores of the faceplate assembly and bores of the backplate assembly;   a first gear and a first rotor mounted for rotation on the first shaft within the chamber; and   a second gear and a second rotor mounted for rotation on the second shaft within the chamber,
 wherein the first gear is intermeshed with the second gear and is configured to transfer fluid from the suction port to the discharge port during rotation of the first shaft and the second shaft, and 
 wherein the first rotor is intermeshed with the second rotor and is configured to transfer fluid from the suction port to the discharge port during rotation of the first shaft and the second shaft. 
   
     
     
         2 . The pump of  claim 1 , wherein the first gear and the first rotor together extend axially for a distance approximately equal to a width of the chamber, and
 wherein the second gear and the second rotor together extend axially for a distance approximately equal to the width of the chamber.   
     
     
         3 . The pump of  claim 1 , wherein the first shaft simultaneously drives rotation of the first gear and the first rotor, and
 wherein the first gear drives rotation of the second gear, the second shaft, and the second rotor.   
     
     
         4 . The pump of  claim 1 , wherein the fluid serves as a lubricant for the first gear and the second gear. 
     
     
         5 . The pump of  claim 1 , further comprising:
 a third rotor mounted for rotation on the first shaft within the chamber; and   a fourth rotor mounted for rotation on the second shaft within the chamber,
 wherein the first gear, the first rotor, and the third rotor together extend axially for a distance approximately equal to a width of the chamber, and 
 wherein the second gear, the second rotor, and the fourth rotor together extend axially for a distance approximately equal to the width of the chamber. 
   
     
     
         6 . The pump of  claim 1 , wherein the first gear and the first rotor are oriented to provide a continuous seal across a width of the chamber throughout a complete rotation of the first shaft. 
     
     
         7 . The pump of  claim 1 , wherein the first rotor includes an elastomeric coating on a circumference of the first rotor. 
     
     
         8 . The pump of  claim 1 , wherein the first rotor includes multiple lobes,
 wherein a support roller is installed at an end of each of the multiple lobes, and   wherein each of the support rollers is configured to contact a curved wall of the chamber.   
     
     
         9 . An assembly for a gear pump, comprising:
 a first gear and a first rotor mounted for rotation on a first shaft; and   a second gear and a second rotor mounted for rotation on a second shaft,
 wherein the first shaft and the second shaft are configured to extend through a gear chamber of the gear pump with the first gear, the first rotor, the second gear, and the second rotor contained in the gear chamber, 
 wherein, when installed in the gear chamber, the first gear is configured to intermesh with the second gear, and 
 wherein, when installed in the gear chamber, the first rotor is configured to intermesh with the second rotor. 
   
     
     
         10 . The assembly of  claim 9 , wherein the first gear and the first rotor together are configured to extend axially along the first shaft for a distance approximately equal to a width of the gear chamber. 
     
     
         11 . The assembly of  claim 10 , wherein the first gear extends axially along the first shaft for a distance of more than half the width of the gear chamber. 
     
     
         12 . The assembly of  claim 9 , wherein the first gear and the second gear are identical parts,
 wherein the first rotor and the second rotor are identical parts,   wherein the first shaft includes a first rotor key seat and a first gear key seat positioned in a first angular orientation relative to each other, and   wherein the second shaft includes a second rotor key seat and a second gear key seat positioned in a second angular orientation, relative to each other, that is different than the first angular orientation.   
     
     
         13 . The assembly of  claim 9 , wherein the first gear is configured to drive rotation of the second gear, the second shaft, and the second rotor. 
     
     
         14 . The assembly of  claim 9 , further comprising:
 a third rotor mounted for rotation on the first shaft; and   a fourth rotor mounted for rotation on the second shaft,
 wherein the first gear, the first rotor, and the third rotor together are configured to extend axially for a distance approximately equal to a width of the gear chamber, and 
 wherein the second gear, the second rotor, and the fourth rotor together are configured to extend axially for a distance approximately equal to the width of the gear chamber. 
   
     
     
         15 . An assembly for a gear pump, comprising:
 a first gear and a first rotor mounted for rotation on a first shaft;   a second gear and a second rotor mounted for rotation on a second shaft; and   a case extension including an extended gear housing that is configured to align with a gear chamber of a main case of the gear pump to form a combined chamber,
 wherein the first shaft and the second shaft are configured to extend through the combined chamber with the first gear, the first rotor, the second gear, and the second rotor contained in the combined chamber, 
 wherein, when installed in the combined chamber, the first gear is configured to intermesh with the second gear, and 
 wherein, when installed in the combined chamber, the first rotor is configured to intermesh with the second rotor. 
   
     
     
         16 . The assembly of  claim 15 , further comprising:
 a plate positioned between the first gear and the first rotor and between the second gear and the second rotor,   wherein the plate includes a set of holes through which the first shaft and the second shaft pass.   
     
     
         17 . The assembly of  claim 15 , wherein first shaft includes a drive end, and
 wherein the first rotor is located between the first gear and the drive end.   
     
     
         18 . A method for reconfiguring a volumetric displacement capacity of a gear pump, the method comprising:
 disconnecting a faceplate assembly from a case of the gear pump;   removing a shaft and gear set from a gear chamber of the case;   inserting a replacement assembly into the gear chamber of the case, wherein the replacement assembly includes:
 a first gear and a first rotor mounted for rotation on a first shaft, and 
 a second gear and a second rotor mounted for rotation on a second shaft; 
   placing the faceplate assembly onto the first shaft and the second shaft and against the case; and   securing the faceplate assembly to the case.   
     
     
         19 . The method of  claim 18 , wherein inserting the replacement assembly into the gear chamber includes:
 intermeshing the first gear with the second gear in the gear chamber, and   intermeshing the first rotor with the second rotor in the gear chamber.   
     
     
         20 . The method of  claim 18 , wherein inserting the replacement assembly into the gear chamber includes:
 inserting an end of the first shaft, of the replacement assembly, into a bore in a backplate of the gear pump, wherein the first shaft includes the first rotor and the first gear keyed to the first shaft, and   inserting an end of the second shaft, of the replacement assembly, into another bore in the backplate of the gear pump, wherein the second shaft includes the second rotor and the second gear keyed to the second shaft.