Roller vane pump with integrated motor

Abstract

A pump includes a housing with an inlet and an outlet, and a stator that generates a rotating magnetic field and defines a pumping chamber. A rotor mounted for axial rotation within the pumping chamber has salient poles to interact with the field. The rotor mounts eccentrically such that a gap between the rotor body and stator varies circumferentially. The rotor defines hollows intermediate the salient poles with cylindrical rollers for free radial movement therein. Fluid-filled volumes are formed between the housing, the rotor and the rollers. On each side of a plane passing through the rotor axis and the housing axis, the pumping chamber is in fluid communication with the inlet or outlet, respectively. The volume expands on one side of the plane and contracts on the other. As the rotor spins, the expanding volume draws fluid from the inlet and the contracting volume expels fluid from the outlet.

1 . A roller vane pump assembly comprising:
 a) a housing defining an interior, at least one inlet for admitting fluid in and at least one outlet for allowing fluid out of the interior;   b) a stator assembly within the interior having a stator and windings for generating a rotating magnetic field, wherein the stator assembly defines a pumping chamber about a stator axis within the interior;   c) a rotor assembly mounted for rotation about a rotor axis within the pumping chamber, the rotor assembly including a body having projections that act as salient poles to interact with the rotating magnetic field, the body also defining a plurality of hollows intermediate the projections, wherein the rotor assembly is mounted eccentrically with respect to the pumping chamber such that a plane substantially passing through the rotor and stator axis defines first and second sides of the body; and   d) a plurality of cylindrical rollers, each roller disposed in a respective hollow for free radial movement within the hollow,   wherein as the body spins due to the rotating magnetic field, volumes between adjacent rollers, the rotor assembly and the pumping chamber expand on the first side of the rotor drawing fluid from the at least one inlet and contract on the second side expelling the fluid from the at least one outlet.   
   
   
       2 . A vane pump assembly as recited in  claim 1 , wherein the stator assembly further comprises a filler material that defines the pumping chamber and secures the stator assembly in place. 
   
   
       3 . A vane pump assembly as recited in  claim 1 , wherein the stator assembly further comprises a wall for defining the pumping chamber. 
   
   
       4 . A vane pump assembly as recited in  claim 4 , further comprising a permanent magnet coupled to each projection. 
   
   
       5 . A vane pump assembly as recited in  claim 1 , wherein the body is a magnetic material. 
   
   
       6 . A vane pump assembly as recited in  claim 6 , wherein the body has six projections and six hollows, and the stator assembly has nine windings. 
   
   
       7 . A vane pump assembly comprising:
 a) a cylindrical pumping wall having an inner circumferential surface defining a pumping chamber;   b) a rotor assembly eccentrically mounted with respect to the cylindrical pumping wall for axial rotation, the rotor assembly having a rotor body defining a plurality of circumferentially spaced apart radially extending vane pockets intermediate projections, each projection being magnetic;   c) a cylindrical roller supported in each radially extending vane pocket;   d) a stator assembly surrounding the cylindrical pumping wall and having windings for generating a magnetic field to act upon the projections; and   e) a housing surrounding the stator assembly and defining inlet and outlet ports for ingress and egress of fluid.   
   
   
       8 . A vane pump assembly as recited in  claim 7 , wherein the rotor body has six projections and six vane pockets and the stator assembly has nine windings. 
   
   
       9 . A vane pump assembly as recited in  claim 7 , wherein the cylindrical pumping wall includes a closed end and an open end, which has been sealed to the housing to form a pressure boundary about the rotor assembly and within the stator assembly. 
   
   
       10 . A vane pump assembly as recited in  claim 9 , wherein the open end of the cylindrical pumping chamber has a flange that is hermetically sealed to an annular groove formed in an inner face of the housing. 
   
   
       11 . A vane pump assembly as recited in  claim 7 , wherein the stator assembly further comprises a filler material that secures the stator assembly in place. 
   
   
       12 . A vane pump assembly as recited in  claim 7 , further comprising a permanent magnet coupled to each projection. 
   
   
       13 . A vane pump assembly as recited in  claim 1 , wherein the rotor body is a soft magnetic material. 
   
   
       14 . A roller vane pump assembly comprising:
 a) a housing defining an interior, at least one inlet for admitting fluid in and at least one outlet for allowing fluid out of the interior;   b) a stator with windings in the interior for generating a rotating magnetic field, the stator having a wall defining a pumping chamber;   c) a rotor body mounted for axial rotation within the pumping chamber, the rotor body having projections that act as salient poles to interact with the rotating magnetic field, the rotor body also defining a plurality of hollows intermediate the projections, wherein the rotor body is mounted eccentrically with respect to the pumping chamber such that a gap between the rotor body and pumping chamber varies from a relatively wide portion to a relatively narrow portion, the gap being in fluid communication with the inlet and outlet; and   d) a plurality of cylindrical rollers disposed in the hollows for free radial movement within the hollows such that as the rotor body spins due to the rotating magnetic field, the widening gap draws fluid from the inlet and the narrowing gap expells the fluid from the outlet.   
   
   
       15 . A vane pump assembly as recited in  claim 1 , wherein the roller seating deeper into the associated hollow provides a secondary pumping effect. 
   
   
       16 . A vane pump assembly as recited in  claim 1 , further comprising a permanent magnet coupled to each projection. 
   
   
       17 . A vane pump assembly as recited in  claim 1 , wherein the rotor body is a magnetic material. 
   
   
       18 . A roller vane pump assembly comprising:
 a) a stator assembly having a stator and windings for generating a rotating magnetic field;   b) a rotor assembly mounted for rotation about a rotor axis within a pumping chamber, the rotor assembly including a body having projections that act as salient poles to interact with the rotating magnetic field, the body also defining a plurality of hollows intermediate the projections, wherein the rotor assembly is mounted eccentrically with respect to the pumping chamber such that a plane substantially passing through the rotor and stator axis defines first and second sides of the body; and   c) a plurality of cylindrical rollers, each roller disposed in a respective hollow for free radial movement within the hollow,   wherein as the body spins due to the rotating magnetic field, volumes between adjacent rollers, the rotor assembly and the pumping chamber expand on the first side of the rotor drawing fluid from at least one inlet and contract on the second side expelling the fluid from at least one outlet.   
   
   
       19 . A roller vane pump assembly as recited in  claim 18 , further comprising a housing defining the at least one inlet and the at least one outlet.