Gerotor Pump

Abstract

A gerotor pump has a pump body having a cavity for housing an outer rotor having an outer surface which slides on the surface of the cavity, and an inner surface with lobes projecting inwards of the outer rotor; and an inner rotor, which is fitted to a drive shaft having an axis of rotation, and has lobes which mesh with the lobes of the outer rotor. The inner rotor is divided into at least two lobed portions by cutting the inner rotor along a plane substantially perpendicular to the axis of rotation.

1 ) A gerotor pump comprising a pump body closed by a cover; said pump body having a cavity for housing:
 an outer rotor having an outer surface which slides on the surface of said cavity, and an inner surface with lobes projecting inwards of the outer rotor; and   an inner rotor which is fitted to a drive shaft having an axis of rotation, and has lobes which mesh with the lobes of the outer rotor; wherein said inner rotor is divided into at least two lobed portions by cutting said inner rotor along a plane substantially perpendicular to said axis; and   a partition disk located between the two lobed portions separates a first pumping chamber and a second pumping chamber; said partition disk having a central through hole through which said drive shaft is fitted.   
   
   
       2 ) A gerotor pump as claimed in  claim 1 , wherein the outer rotor is also divided into at least two lobed portions by cutting said outer rotor along said plane. 
   
   
       3 ) A gerotor pump as claimed  claim 1 , wherein the at least two lobed portions are mounted offset with respect to each other by an offset angle formed between a lobe of a first lobed portion and a lobe of a second lobed portion. 
   
   
       4 ) A gerotor pump as claimed in  claim 3 , wherein the offset angle is such that at least one lobe of said second lobed portion corresponds to a gap between two adjacent lobes of said first lobed portion. 
   
   
       5 ) A gerotor pump as claimed in  claim 1  wherein the at least two lobed portions are mounted on a grooved drive shaft, and each have similar grooves formed in a respective central through hole formed in each first and second lobed portion. 
   
   
       6 ) A gerotor pump as claimed in  claim 1 , wherein the first pumping chamber is defined at one end by the end of the cavity, and at the other end by a first face of the partition disk; the first pumping chamber housing at least one lobed portion and a first portion of the drive shaft. 
   
   
       7 ) A gerotor pump as claimed in  claim 1 , wherein the second pumping chamber is defined at one end by the end of the cover, and at the other end by a second face of the partition disk; the second pumping chamber housing at least one lobed portion and a second portion of the drive shaft. 
   
   
       8 ) A gerotor pump as claimed in  claim 1 , characterized in that said partition disk is configured such that it rotates with the outer rotor. 
   
   
       9 ) A gerotor pump as claimed in  claim 8 , wherein a fastener comprising at least one pin which engages at least one seat formed in a face of a lobed portion of the outer rotor, and a seat formed in the partition disk. 
   
   
       10 ) A gerotor pump as claimed in  claim 8 , wherein each pumping chamber has at least one intake conduit and at least one delivery conduit. 
   
   
       11 ) A gerotor pump as claimed in  claim 1 , wherein the partition disk located between the two lobed portions to separate a first pumping chamber and a second pumping chamber is a contoured disk. 
   
   
       12 ) A gerotor pump as claimed in  claim 11 , wherein the contoured disk has at least one of openings, grooves, slits or dead cavities to permit flow between the two pumping chambers. 
   
   
       13 ) A gerotor pump as claimed in  claim 12  wherein the contoured disk is mounted such that it is fixed with respect to the cavity in the pump body.