Vane pumps and methods of operating same

Abstract

A vane pump ( 20 ) including: a housing ( 21 ), a first motor ( 23 ) arranged to rotate a shaft ( 22 ) mounted about the shaft axis, a rotor ( 24 ) mounted for rotation with the shaft, and a member ( 28 ) having a surface ( 29 ) and having a member axis. The member is movable relative to the shaft axis through a permissible range of motion which includes portions on either side of a null position. A vane ( 32 ) is movably mounted in each rotor slot, and has a distal end arranged to engage the member surface. The vanes define with the rotor and surface a plurality of chambers ( 33 A- 33 F). The individual volumes of the chambers vary as a function of the relative position between the rotor and surface. A second motor ( 31 ) is operatively arranged to selectively move the member relative to the shaft axis through the permissible range of motion. Movement of the member off-null in one direction along the range of motion will enable fluid flow in a first direction between the ports, while movement of the member off-null in the opposite direction along the range of motion will enable fluid flow in the opposite direction between the ports.

What is claimed is: 
     
         1 . A vane pump, comprising:
 a housing;   a shaft having a shaft axis, said shaft being mounted on said housing for rotation about said shaft axis;   a first motor operatively arranged to selectively rotate said shaft;   a rotor mounted for rotation with said shaft, said rotor having a plurality of circumferentially-spaced slots;   a member having a surface and having a member axis, said member being movable relative to said shaft axis through a permissible range of motion which includes portions on either side of a null position;   wherein said member axis is coincident with said shaft axis when said member is in said null position;   a vane movably mounted in each rotor slot and having a distal end arranged to engage said member surface;   said vanes defining with said rotor and surface a plurality of chambers, the individual volumes of said chambers varying as a function of the relative position between said rotor and surface;   said housing having two fluid passageways operatively arranged to communicate with two of said chambers as a function of the angular position of said rotor relative to said housing;   a second motor operatively arranged to selectively move said member relative to said shaft axis through said permissible range of motion;   wherein movement of said member off null in one direction along said range of motion will enable fluid flow in a first direction between said ports; and   wherein movement of said member off null in the opposite direction along said range of motion will enable fluid flow in the opposite direction between said ports.   
     
     
         2 . A vane pump as set forth in  claim 1  wherein said member has passageways that communicate with said housing passageways and that terminate in ports at said surface. 
     
     
         3 . A vane pump as set forth in  claim 1 , and further comprising:
 a boundary seal separating a wet portion of said second motor from a dry portion of said second motor; and   wherein said second motor has one portion arranged on one side of said seal and has another portion arranged on the other side of said seal.   
     
     
         4 . A vane pump as set forth in  claim 3  wherein said one portion includes a permanent magnet, and said other portion includes a coil. 
     
     
         5 . A vane pump as set forth in  claim 1  wherein said member is mounted on said housing. 
     
     
         6 . A vane pump as set forth in  claim 5  wherein said member is mounted on said housing by a flexure member. 
     
     
         7 . A vane pump as set forth in  claim 6  wherein said range of motion is arcuate. 
     
     
         8 . A vane pump as set forth in  claim 1  wherein said range of motion is linear. 
     
     
         9 . A vane pump as set forth in  claim 1 , and further comprising:
 a resilient member acting between said housing and said member for urging said member to move toward said null position.   
     
     
         10 . A vane pump, comprising:
 a housing;   a shaft having a shaft axis, said shaft being mounted on said housing for rotation about said shaft axis;   a first motor mounted on said housing and operatively arranged to selectively rotate said shaft;   a plurality of rotors mounted for rotation with said shaft at spaced locations therealong, each rotor having a plurality of circumferentially-spaced slots;   a plurality of members, each member having a surface and having a member axis, each member being associated with a respective one of said rotors and being movable relative to said shaft axis through a permissible range of motion which includes portions on either side of a null position;   wherein each member axis is coincident with said shaft axis when the associated member is in said null position;   a vane movably mounted in each rotor slot and having a distal end arranged to engage the surface of the associated member;   said vanes defining with the associated rotor and surface a plurality of chambers, the individual volumes of said chambers varying as a function of the relative position between said associated rotor and surface;   said housing having two fluid passageways operatively arranged to communicate with two of said chambers for each member as a function of the angular position of said rotor relative to said housing;   a plurality of second motors operatively arranged to selectively move the associated member relative to said shaft axis through its permissible range of motion;   wherein movement of each member off null in one direction along the range of motion of such member will enable fluid flow in a first direction between the ports of such member; and   wherein movement of each member off null in the opposite direction along the range of motion of such member will enable fluid flow in the opposite direction between the ports of such member.   
     
     
         11 . A vane pump as set forth in  claim 10  wherein said member has passageways that communicate with said housing passageways and that terminate in ports at said surface. 
     
     
         12 . A vane pump as set forth in  claim 10  wherein said plurality of members are stackable at axially-spaced locations along said shaft. 
     
     
         13 . A vane pump as set forth in  claim 10  wherein the fluid output of each member is controllable independently. 
     
     
         14 . A vane pump as set forth in  claim 10 , and further comprising:
 a plurality of boundary seals, each boundary seal separating a wet portion of an associated second motor from a dry portion of such associated second motor; and   wherein each second motor has one portion arranged on one side of the associated seal and has another portion arranged on the other side of such associated seal.   
     
     
         15 . A vane pump as set forth in  claim 14  wherein said one portion includes a permanent magnet, and said other portion includes a coil. 
     
     
         16 . A vane pump as set forth in  claim 10  wherein each member is mounted on said housing by a flexure member. 
     
     
         17 . A vane pump as set forth in  claim 10  wherein the range of motion of each member is arcuate. 
     
     
         18 . A vane pump as set forth in  claim 10  wherein the range of motion of each member is linear. 
     
     
         19 . A vane pump as set forth in  claim 10 , and further comprising:
 a resilient member acting between said housing and each member for urging such member to move toward said null position.   
     
     
         20 . A vane pump, comprising:
 a housing;   a shaft having a shaft axis, said shaft being mounted on said housing for rotation about said shaft axis;   a first motor operatively arranged to selectively rotate said shaft;   a rotor mounted for rotation with said shaft, said rotor having a plurality of circumferentially-spaced slots;   a member having a surface and having a member axis, said member being movable relative to said shaft axis through a permissible range of motion which includes portions on either side of a null position;   wherein said member axis is coincident with said shaft axis when said member is in said null position;   a vane movably mounted in each rotor slot and having a distal end arranged to engage said member surface;   a second motor operatively arranged to selectively move said member relative to said shaft axis through said permissible range of motion;   said vanes defining with said rotor and surface a plurality of chambers, the individual volumes of said chambers varying as a function of the relative position between said rotor and surface;   said housing having two fluid passageways operatively arranged to communicate with two of said chambers as a function of the angular position of said rotor relative to said housing; and   wherein the direction of flow between said passageways is a function of the position of said member axis relative to said shaft axis.   
     
     
         21 . A vane pump as set forth in  claim 20  wherein said member has passageways that communicate with said housing passageways and that terminate in ports at said surface. 
     
     
         22 . A vane pump as set forth in  claim 20  wherein the direction of fluid flow between said passageways is in one direction when said member has been moved off null in one direction along said range of motion, and is in the opposite direction when said member has been moved off null in the opposite direction along said range of motion. 
     
     
         23 . A vane pump as set forth in  claim 20 , and further comprising:
 a boundary seal separating a wet portion of said second motor from a dry portion of said second motor; and   wherein said second motor has one portion arranged on one side of said seal and has another portion arranged on the other side of said seal.   
     
     
         24 . A vane pump as set forth in  claim 23  wherein said one portion includes a permanent magnet, and said other portion includes a coil. 
     
     
         25 . A vane pump, comprising:
 a shaft having a shaft axis, said shaft being mounted for rotation about said shaft axis;   a first motor operatively arranged to selectively rotate said shaft about said shaft axis;   a rotor mounted for rotation with said shaft, said rotor having a plurality of circumferentially-spaced slots;   a member having a surface and having a member axis, said member being movable relative to said shaft axis through a permissible range of motion which includes portions on either side of a null position;   wherein said member axis is coincident with said shaft axis when said member is in said null position;   a vane movably mounted in each rotor slot and having a distal end arranged to engage said member surface;   said vanes defining with said rotor and surface a plurality of chambers, the individual volumes of said chambers varying as a function of the relative position between said rotor and surface   a second motor operatively arranged to selectively move said member relative to said shaft axis through said permissible range of motion; and   a boundary seal separating a wet portion of said second motor from a dry portion of said second motor; and   wherein said second motor has one portion arranged on one side of said seal and has another portion arranged on the other side of said seal.   
     
     
         26 . A vane pump as set forth in  claim 20  wherein said member has passageways that communicate with said housing passageways and that terminate in ports at said surface. 
     
     
         27 . A vane pump as set forth in  claim 25  wherein said one portion includes a permanent magnet, and said other portion includes a coil. 
     
     
         28 . The method of operating a vane pump that includes a housing, a rotor having a rotor axis and being rotatably mounted on said housing, said rotor having a plurality of circumferentially-spaced slots; a member having a surface and having a member axis, said member being movable relative to said rotor axis through a permissible range of motion; wherein said member axis is coincident with said shaft axis when said member is in said null position; a vane movably mounted in each rotor slot and having a distal end arranged to engage said member surface; said vanes defining with said rotor and surface a plurality of chambers, the individual volumes of said chambers varying as a function of the relative position between said rotor and surface; comprising the steps of:
 rotating said rotor in one angular direction about said rotor axis;   selectively moving said member relative to said rotor; and   varying the direction of fluid flow between said ports as by varying the position between said rotor and member axes.   
     
     
         29 . The method as set forth in  claim 28 , and further comprising the additional step of:
 varying the magnitude of the fluid flow between said ports by varying the position between said rotor and member axes.   
     
     
         30 . The method as set forth in  claim 28  wherein the position between said rotor and member axes is varied by moving said member relative to said rotor.