Kidney port configurations in port plates for balanced vanes

Abstract

A vane pump system includes a kidney port plate engaged at an axial end of a rotor and liner. The port kidney plate includes an over vane inlet port configured to be circumferentially aligned with an inlet arc segment of a circumferential cam surface of the liner for ingress of fluid to a plurality of vanes, and an over vane discharge port configured to be circumferentially aligned with a discharge arc segment of the circumferential cam surface for discharging pressurized fluid from the plurality of vanes. The kidney port plate includes at least six kidney ports radially inward from the over vane inlet port and the over vane discharge port. The kidney ports are circumferentially spaced apart from one another. The kidney ports are configured to be radially aligned with vane slots of the rotor for pressure balancing across over vane and under vane ends of the plurality of vanes.

1 .- 20 . (canceled) 
     
     
         21 . A vane pump system comprising:
 a liner having a bore extending therethrough and defining a circumferential cam surface of a pumping cavity, with a rotation axis defined in an axial direction through the bore, the circumferential cam surface of the pumping cavity including a first inlet arc segment, a first pump arc segment, a first discharge arc segment, a first seal segment, a second inlet arc segment, a second pump arc segment, a second discharge arc segment, and a second seal arc segment spaced circumferentially in series; and   a rotor mounted for rotational movement within the bore of the liner about the rotation axis, the rotor having a central body portion which includes vane slots, which are a plurality of circumferentially spaced apart radially extending vane slots formed in the rotor, each vane slot supporting a corresponding one of the plurality of vanes mounted for radial movement therein, each vane in the plurality of vanes having a radially outer tip surface adapted for slideably engaging the circumferential cam surface of the pumping cavity and a radially inner portion within each vane slot;   a kidney port plate configured to be engaged at an axial end of the rotor and of the liner, wherein the kidney port plate is configured to be mounted stationary relative to the liner, wherein the kidney port plate includes:
 first and second over vane inlet ports configured to be circumferentially aligned with the first and second inlet arc segments, respectively of the circumferential cam surface of the liner for ingress of fluid to the plurality of vanes; 
 first and second over vane discharge ports configured to be circumferentially aligned with the first and second discharge arc segments, respectively, of the circumferential cam surface for discharging pressurized fluid from the plurality of vanes; and 
 at least eight kidney ports including:
 a first inlet kidney port circumferentially aligned with the first inlet arc segment; 
 a first regulated pressure kidney port circumferentially adjacent to the first inlet kidney port and circumferentially aligned with the first pump arc segment; 
 a first discharge kidney port circumferentially adjacent to the first regulated pressure kidney port and circumferentially aligned with the first discharge arc segment; 
 a second regulated pressure kidney port circumferentially adjacent to the first discharge kidney port and circumferentially aligned with the first seal arc segment; 
 a second inlet kidney port circumferentially adjacent to the second regulated pressure kidney port and circumferentially aligned with the second inlet arc segment; 
 a third regulated pressure kidney port circumferentially adjacent to the second inlet kidney port and circumferentially aligned with the second pump arc segment; 
 a second discharge kidney port circumferentially adjacent to the third regulated pressure kidney port and circumferentially aligned with the second discharge arc segment; and 
 a fourth regulated pressure kidney port circumferentially adjacent to the second discharge kidney port and the first inlet kidney port, wherein the fourth regulated pressure kidney port is circumferentially aligned with a second seal arc segment; 
 wherein the kidney ports are radially inward from the over vane inlet port and the over vane discharge port, and 
 wherein the kidney ports are circumferentially spaced apart from one another, and 
 wherein the kidney ports are configured to be radially aligned with the vane slots of the rotor for pressure balancing across over vane and under vane ends of the plurality of vanes; 
 
   a first fluid communication passage is included configured so over vane pressure can be ported to the first and second discharge kidney ports;   a second fluid communication passage is included configured so vane pump inlet pressure can be ported to the first and second inlet kidney ports;   a pressure regulating valve (PRV) in a pressure balancing passage configured so pressure from the over vane discharge ports can be ported to the first, second, third, and fourth regulated pressure kidney ports, wherein the PRV is configured to reduce pressure from the discharge to an intermediate pressure between inlet pressure and discharge pressure of the rotor to balance vane loading in the first and second pump arc segments and in the first and second seal arc segments such that the under vane pressure matches exactly the over vane pressures or provides a slightly positive net pressure loading on the vane towards the liner.   
     
     
         22 . The system as recited in  claim 21 , further comprising a pressure loaded port plate mounted to an axial end of the liner opposite across the liner from the kidney port plate, wherein the pressure loaded port plate is fixed relative to the liner. 
     
     
         23 . The system as recited in  claim 22 , further comprising a shouldered end cap mounted to the pressure loaded port plate and to the liner, with the shouldered end cap radially outboard of the liner, and with the pressure loaded port plate axially between the shouldered end cap and the liner. 
     
     
         24 . The system as recited in  claim 23 , further comprising a discharge end cap mounted to the kidney port plate, with the kidney port plate axially between the discharge end cap and the liner. 
     
     
         25 . The system of  claim 24 , wherein the first communication passage extends through at least one of the rotor, the kidney port plate, the shouldered end cap, or the discharge end cap. 
     
     
         26 . The system of  claim 24 , wherein the second communication passage extends through at least one of the rotor, the kidney port plate, the shouldered end cap, or the discharge end cap. 
     
     
         27 . The system as recited in  claim 21 , wherein the pressure balancing passage is configured so pressure can be ported to the first, second, third, and fourth regulated kidney ports through at least one of the discharge end cap and the shouldered end cap. 
     
     
         28 . A vane pump system comprising:
 a kidney port plate configured to be engaged at an axial end of a rotor and of a liner, wherein the kidney port plate is configured to be mounted stationary relative to the liner, wherein the kidney port plate includes:
 first and second over vane inlet ports configured to be circumferentially aligned with first and second inlet arc segments, respectively of a circumferential cam surface of the liner for ingress of fluid to a plurality of vanes; 
 first and second over vane discharge ports configured to be circumferentially aligned with first and second discharge arc segments, respectively, of the circumferential cam surface for discharging pressurized fluid from the plurality of vanes; and
 a first inlet kidney port; 
 
 at least six kidney ports including:
 a first inlet kidney port; 
 a first discharge kidney port circumferentially adjacent to the first inlet kidney port; 
 a first regulated pressure kidney port circumferentially adjacent to the first discharge kidney port and circumferentially aligned with a first seal arc segment circumferentially disposed between the first discharge arc segment and the second inlet arc segment; 
 a second inlet kidney port circumferentially adjacent to the first regulated pressure kidney port; 
 a second discharge kidney port circumferentially adjacent to the second inlet pressure kidney port; and 
 a second regulated pressure kidney port circumferentially adjacent to the second discharge kidney port and circumferentially adjacent to the first inlet kidney port, wherein the second regulated pressure kidney port is circumferentially aligned to a second seal arc segment circumferentially between the second discharge arc segment and the first inlet arc segment, 
 wherein the kidney ports are radially inward from the over vane inlet port and the over vane discharge port, and 
 wherein the kidney ports are circumferentially spaced apart from one another, and 
 wherein the kidney ports are configured to be radially aligned with vane slots of the rotor for pressure balancing across over vane and under vane ends of the plurality of vanes; and 
 
   a pressure regulating valve (PRV) in a pressure balancing passage configured so pressure from the over vane discharge port can be ported to the first and second regulated pressure kidney ports, wherein the PRV is configured to reduce pressure from the over vane discharge port to an intermediate pressure between inlet pressure and discharge pressure of the rotor to balance vane loading in the first and second seal arc segments such that the under vane pressure matches exactly the over vane pressures or provides a slightly positive net pressure loading on the vane towards the liner.   
     
     
         29 . A vane pump system comprising:
 a kidney port plate configured to be engaged at an axial end of the rotor and of the liner, wherein the kidney port plate is configured to be mounted stationary relative to the liner, wherein the kidney port plate includes:
 first and second over vane inlet ports configured to be circumferentially aligned with the first and second inlet arc segments, respectively of a circumferential cam surface of a liner for ingress of fluid to a plurality of vanes; 
 first and second over vane discharge ports configured to be circumferentially aligned with the first and second discharge arc segments, respectively, of the circumferential cam surface for discharging pressurized fluid from the plurality of vanes; and 
 at least eight kidney ports including:
 a first inlet kidney port circumferentially aligned with the first inlet arc segment; 
 a first regulated pressure kidney port circumferentially adjacent to the first inlet kidney port and circumferentially aligned with the first pump arc segment; 
 a first discharge kidney port circumferentially adjacent to the first regulated pressure kidney port and circumferentially aligned with the first discharge arc segment; 
 a second regulated pressure kidney port circumferentially adjacent to the first discharge kidney port and circumferentially aligned with the first seal arc segment; 
 a second inlet kidney port circumferentially adjacent to the second regulated pressure kidney port and circumferentially aligned with the second inlet arc segment; 
 a third regulated pressure kidney port circumferentially adjacent to the second inlet kidney port and circumferentially aligned with the second pump arc segment; 
 a second discharge kidney port circumferentially adjacent to the third regulated pressure kidney port and circumferentially aligned with the second discharge arc segment; and 
 a fourth regulated pressure kidney port circumferentially adjacent to the second discharge kidney port and the first inlet kidney port, wherein the fourth regulated pressure kidney port is circumferentially aligned with a second seal arc segment; 
 wherein the kidney ports are radially inward from the over vane inlet port and the over vane discharge port, and 
 wherein the kidney ports are circumferentially spaced apart from one another, and 
 wherein the kidney ports are configured to be radially aligned with the vane slots of the rotor for pressure balancing across over vane and under vane ends of the plurality of vanes; and 
 
   a pressure regulating valve (PRV) in a pressure balancing passage configured so pressure from the over vane discharge ports can be ported to the first, second, third, and fourth regulated pressure kidney ports, wherein the PRV is configured to reduce pressure from the discharge to an intermediate pressure between inlet pressure and discharge pressure of the rotor to balance vane loading in the first and second pump arc segments and in the first and second seal arc segments such that the under vane pressure matches exactly the over vane pressures or provides a slightly positive net pressure loading on the vane towards the liner.