Electronic positive displacement fluid pump with pumping ring alignment

Abstract

A positive displacement fluid pump is provided. The fluid pump includes a motor and a pumping portion driven by the motor. The pumping portion includes an internal plate, an external plate including a fluid inlet and a fluid outlet, a pumping ring sandwiched between the internal and external plates, and a pumping arrangement rotatably coupled to the motor and located within the pumping ring. The pumping ring includes at least two alignment holes extending through the pumping ring in an axial direction. The internal plate and the external plate each including a corresponding number of axially-extending alignment holes, respectively. An alignment pin is provided for each of the alignment holes of the pumping ring. The alignment holes are aligned with each other, and the alignment pins are positioned in the aligned alignment holes. A method of aligning components of a positive displacement fluid pump is also provided.

1 . A positive displacement fluid pump comprising:
 a motor having a drive shaft that rotates about an axis extending in an axial direction;   a pumping portion driven by the motor;   the pumping portion including:
 an internal plate including a central bore through which the drive shaft extends; 
 an external plate including a fluid inlet and a fluid outlet; 
 a pumping ring sandwiched between the internal and external plates; and 
 a pumping arrangement rotatably coupled to the drive shaft such that rotation of the pumping arrangement by the drive shaft causes fluid to be pumped from the fluid inlet to the fluid outlet, the pumping arrangement being located within the pumping ring and axially between the internal plate and the external plate; 
   the pumping ring including at least two alignment holes extending through the pumping ring in the axial direction;   the internal plate and the external plate each including a corresponding number of axially-extending alignment holes, respectively; and   an alignment pin for each of the alignment holes of the pumping ring;   wherein the alignment holes of the pumping ring are aligned with the alignment holes of the internal plate and the alignment holes of the external plate, and the alignment pins are positioned in the alignment holes of the pumping ring and extend into the alignment holes of the internal and external plates to maintain the relative disposition of the pumping ring to the internal and external plates.   
     
     
         2 . The positive displacement fluid pump of  claim 1 , wherein the alignment holes of the pumping ring include a primary alignment hole and a secondary alignment hole. 
     
     
         3 . The positive displacement fluid pump of  claim 2 , wherein the primary alignment hole and the secondary alignment hole of the pumping ring are both circular in cross-sectional shape. 
     
     
         4 . The positive displacement fluid pump of  claim 2 , wherein the alignment holes of the internal plate and the alignment holes of the external plate each include a primary alignment hole and a secondary alignment hole corresponding to the primary and secondary alignment holes of the pumping ring, respectively. 
     
     
         5 . The positive displacement fluid pump of  claim 4 , wherein the primary alignment hole of the internal plate and the primary alignment hole of the external plate are each circular in cross-sectional shape. 
     
     
         6 . The positive displacement fluid pump of  claim 4 , wherein the secondary alignment hole of the internal plate and the secondary alignment hole of the external plate have an elongated cross-sectional shape. 
     
     
         7 . The positive displacement fluid pump of  claim 6 , wherein the secondary alignment hole of the internal plate and the secondary alignment hole of the external plate are oval in cross-sectional shape. 
     
     
         8 . The positive displacement fluid pump of  claim 1 , wherein the pumping ring includes only two alignment holes, and the internal plate and the external plate each include only two corresponding alignment holes. 
     
     
         9 . The positive displacement fluid pump of  claim 1 , wherein the alignment holes of the internal plate do not extend through the internal plate in the axial direction, and the alignment holes of the external plate do not extend through the external plate in the axial direction. 
     
     
         10 . The positive displacement fluid pump of  claim 1 , wherein the alignment pins are coiled pins. 
     
     
         11 . The positive displacement fluid pump of  claim 1 , wherein the internal plate includes an inwardly-facing face surface and an opposite, outwardly-facing face surface, the outwardly-facing face surface of the internal plate being adjacent to the pumping ring; and
 the external plate includes an inwardly-facing face surface and an opposite, outwardly-facing face surface, the inwardly-facing face surface of the external plate being adjacent to the pumping ring.   
     
     
         12 . The positive displacement fluid pump of  claim 11 , wherein the alignment holes of the internal plate are formed in the outwardly-facing face surface of the internal plate, and the alignment holes of the external plate are formed in the inwardly-facing face surface of the external plate. 
     
     
         13 . The positive displacement fluid pump of  claim 11 , wherein the external plate includes a suction port formed in the inwardly-facing face surface of the external plate, the suction port of the external plate being connected to and in fluid communication with the fluid inlet. 
     
     
         14 . The positive displacement fluid pump of  claim 13 , wherein the internal plate includes a complementary suction port formed in the outwardly-facing face surface of the internal plate, the complementary suction port being in fluid communication with the fluid inlet. 
     
     
         15 . The positive displacement fluid pump of  claim 14 , wherein the complementary suction port of the internal plate is connected to the fluid inlet by a suction passage that extends through the pumping ring. 
     
     
         16 . The positive displacement fluid pump of  claim 11 , wherein the external plate includes a delivery port formed in the inwardly-facing face surface of the external plate, the delivery port of the external plate being connected to and in fluid communication with the fluid outlet. 
     
     
         17 . The positive displacement fluid pump of  claim 16 , wherein the internal plate includes a complementary delivery port formed in the outwardly-facing face surface of the internal plate. 
     
     
         18 . The positive displacement fluid pump of  claim 1 , wherein the pumping arrangement includes a rotating element that is an inner gear rotor mounted on the drive shaft, and the pumping arrangement further includes an outer gear rotor engaged and driven by the inner gear rotor, the inner gear rotor and outer gear rotor together defining a plurality of variable volume pumping chambers in fluid communication with the inlet and the outlet; and
 the pumping ring is an eccentric ring having a circular gear rotor bore that is offset from the axis of the drive shaft.   
     
     
         19 . The positive displacement fluid pump of  claim 18 , wherein the eccentric ring and the inner and outer gear rotors of the pumping arrangement are made of materials having a similar coefficient of thermal expansion (CTE). 
     
     
         20 . A method of aligning components of a positive displacement fluid pump, the method comprising the steps of:
 providing a motor having a drive shaft that rotates about an axis extending in an axial direction;   providing a pumping portion including:
 an internal plate including a central bore through which the drive shaft extends; 
 an external plate including a fluid inlet and a fluid outlet; 
 a pumping ring sandwiched between the internal and external plates; and 
 a pumping arrangement rotatably coupled to the drive shaft, the pumping arrangement being located within the pumping ring and axially between the internal plate and the external plate; 
   forming at least two alignment holes that extend through the pumping ring in the axial direction;   forming a corresponding number of axially-extending alignment holes in each of the internal plate and the external plate;   providing an alignment pin for each of the alignment holes of the pumping ring;   positioning the alignment pins in the alignment holes of the pumping ring; and   aligning the alignment holes of the pumping ring with the alignment holes of the internal plate and the alignment holes of the external plate, whereby the alignment pins also extend into the alignment holes of the internal and external plates to maintain the relative disposition of the pumping ring to the internal and external plates.   
     
     
         21 . The method of  claim 20 , wherein the pumping ring includes only two alignment holes, and the internal plate and the external plate each include only two corresponding alignment holes. 
     
     
         22 . The method of  claim 20 , wherein the alignment holes of the internal plate do not extend through the internal plate in the axial direction, and the alignment holes of the external plate do not extend through the external plate in the axial direction. 
     
     
         23 . The method of  claim 20 , wherein:
 the internal plate includes an inwardly-facing face surface and an opposite, outwardly-facing face surface, the outwardly-facing face surface of the internal plate being adjacent to the pumping ring;   the external plate includes an inwardly-facing face surface and an opposite, outwardly-facing face surface, the inwardly-facing face surface of the external plate being adjacent to the pumping ring; and   the alignment holes of the internal plate are formed in the outwardly-facing face surface of the internal plate, and the alignment holes of the external plate are formed in the inwardly-facing face surface of the external plate.   
     
     
         24 . The method of  claim 20 , wherein the alignment pins are coiled pins.