Vane pump with hydrostatic pressure plates

Abstract

The present disclosure comprises a vane pump with hydrostatic pressure plates, or port plates, to axially center a rotor between the port plates. The port plates comprise a pressurization arrangement configured to provide unequal opposing pressures to the rotor when the rotor moves closer to one of the port plates, which provides a net axial thrust to the rotor to move it towards a central position. The pressurization arrangement can comprise circular grooves in the port plates in fluid communication with a high pressure exhaust zone of the pump. Fluid moves from the exhaust zone, through pressurized lines, into the port plates, through an orifice, and into the grooves. The pressurization arrangement can also comprise inner and outer diameter seal rings concentrically disposed inside and outside the grooves. The seal rings can be comprised of a relatively close clearance to the rotor compared to the grooves.

1 . A vane pump comprising:
 a housing having a fluid inlet opening and a fluid outlet opening;   a cam ring positioned within the housing;   a rotor rotatable about a rotor axis, the rotor and the cam ring being positioned within a pumping chamber of the housing, the rotor having first and second axial rotor faces that face in opposite axial directions, the rotor defining a plurality of radial slots in which vanes are received, the vanes being radially moveable relative to the rotor within the radial slots as the rotor is rotated about the rotor axis to maintain contact with an interior surface of the cam ring;   first and second port plates respectively having first and second axial plate faces that respectively oppose the first and second axial rotor faces and enclose opposite axial ends of the pumping chamber, the first and second port plates each defining at least one inlet port in fluid communication with the fluid inlet opening and at least one outlet port in fluid communication with the fluid outlet opening, the inlet ports being in fluid communication with a suction zone of the pumping chamber, and outlet ports being in fluid communication with a compression/exhaust zone of the of the pumping chamber; and   a pressurization arrangement that uses pressure generated at the compression/exhaust zone to center the rotor between the first and second port plates, the pressurization arrangement being configured to increase axial thrust applied to the second axial rotor face and decrease axial thrust applied to the first axial rotor face when the rotor moves axially toward the second port plate, and the pressurization arrangement being configured to increase axial thrust applied to the first axial rotor face and decrease axial thrust applied to the second axial rotor face when the rotor moves axially toward the first port plate.   
     
     
         2 . The vane pump of  claim 1 , wherein the rotor is supported on a shaft that rotates about the rotor axis relative to the housing, the shaft being supported by bearings. 
     
     
         3 . The vane pump of  claim 1 , wherein the pressurization arrangement includes a first pressurization zone defined between first axial rotor face and the first axial plate face and a second pressurization zone defined between the second axial rotor face and the second axial plate face. 
     
     
         4 . The vane pump of  claim 3 , wherein the first pressurization zone includes a first groove defined by the first port plate at the first axial plate face, the first groove having an open side that faces toward the first axial rotor face, and wherein the second pressurization zone includes a second groove defined by the second port plate at the second axial plate face, the second groove having an open side that faces toward the second axial rotor face. 
     
     
         5 . The vane pump of  claim 4 , wherein the first groove is pressurized by a first pressurization line in fluid communication with the fluid outlet opening, wherein the second groove is pressurized by a second pressurization line in fluid communication with the fluid outlet opening, and wherein an orifice is positioned along each of the first and second pressurization lines. 
     
     
         6 . The vane pump of  claim 4 , wherein the first and second grooves are circular grooves centered radially about the rotor axis. 
     
     
         7 . The vane pump of  claim 6 , wherein the first and second grooves are positioned radially closer to the rotor axis than the inner ends of the vanes and radially further from the rotor axis than an outer circumference of a shaft. 
     
     
         8 . The vane pump of  claim 5 , wherein the first pressurization line extends through an end of the first port plate opposite the first axial plate face, and wherein the second pressurization line extends through an end of the second port plate opposite the second axial plate face. 
     
     
         9 . The vane pump of  claim 5 , wherein the each of the first and second port plates define inner and outer diameter seal rings. 
     
     
         10 . The vane pump of  claim 9 , wherein the inner diameter seal ring and the outer diameter seal ring concentrically surround the first and second grooves, the inner diameter seal rings at a smaller diameter than the first and second grooves and the outer diameter seal rings at a larger diameter than the first and second grooves. 
     
     
         11 . The vane pump of  claim 10 , wherein the inner and outer diameter seal rings are portions of the first and second port plates disposed at a closer clearance to the rotor than the first and second grooves. 
     
     
         12 . The vane pump of  claim 1 , wherein a spacer is positioned against the housing on a radially outward side of the housing. 
     
     
         13 . The vane pump comprising:
 a housing having a fluid inlet opening and a fluid outlet opening;
 a cam ring positioned within the housing; 
 a rotor rotatable about a rotor axis, the rotor and the cam ring being positioned within a pumping chamber of the housing, the rotor having first and second axial rotor faces that face in opposite axial directions, the rotor defining a plurality of radial slots in which vanes are received, the vanes being radially moveable relative to the rotor within the radial slots as the rotor is rotated about the rotor axis to maintain contact with an interior surface of the cam ring; and 
   first and second port plates respectively having first and second axial plate faces that respectively oppose the first and second axial rotor faces and enclose opposite axial ends of the pumping chamber, the first and second port plates each defining at least one inlet port in fluid communication with the fluid inlet opening and at least one outlet port in fluid communication with the fluid outlet opening, the inlet ports being in fluid communication with a suction zone of the pumping chamber, and outlet ports being in fluid communication with a compression/exhaust zone of the of the pumping chamber;
 wherein the first port plate includes a first groove in communication with a plurality of first pressurization line pressurized by fluid from the outlet port and wherein the second port plate includes a first groove in communication with a first pressurization line and a second groove in communication with a plurality of second pressurization lines pressurized by fluid from the outlet port; 
   wherein the rotor is hydrostatically positioned between the first port plate and the second rotor plate by pressurization from the first and second pressurization lines against the first and second axial faces from within the first and second grooves.   
     
     
         14 . The vane pump of  claim 13 , wherein the first and second grooves are circular grooves centered radially about the rotor axis. 
     
     
         15 . The vane pump of  claim 14 , wherein the first and second grooves are positioned radially closer to the rotor axis than the inner ends of the vanes and radially further from the rotor axis than an outer circumference of the shaft. 
     
     
         16 . The vane pump of  claim 13 , wherein the first pressurization line extends through an end of the first port plate opposite the first axial plate face, and wherein the second pressurization line extends through an end of the second port plate opposite the second axial plate face. 
     
     
         17 . The vane pump of  claim 13 , wherein the each of the first and second port plates define inner and outer seal rings. 
     
     
         18 . The vane pump of  claim 13 , wherein the rotor is supported on a shaft that rotates about the rotor axis relative to the housing, the shaft being supported by bearings. 
     
     
         19 . The vane pump of  claim 13 , wherein the inlet ports concentrically extend partially around the port plates. 
     
     
         20 . The vane pump of  claim 13 , wherein the outlet ports concentrically extend partially around the port plates.