Multi-discharge hydraulic vane pump

Abstract

A hydraulic vane pump includes a pump body defining an interior pumping chamber, an inlet port, and at least one discharge port. A cam ring is disposed within the interior pumping chamber and defines a continuous peripheral cam surface. A rotor is mounted for axial rotation within the interior pumping chamber. A plurality of vanes are mounted for radial movement within slots formed in the rotor. The pump includes axially opposed first and second wear disks disposed within the interior pumping chamber. The first wear disk is a floating wear disk and has an outer periphery which is positioned radially inward of the cam surface and is adapted and configured to slide axially with respect to the cam surface. The second wear disk is positioned adjacent to a second end surface of the rotor.

What is claimed is: 
     
         1 . A hydraulic vane pump, comprising:
 a) a pump body including an interior pumping chamber and defining an inlet port for allowing fluid to be provided to the interior pumping chamber and at least one discharge port for allowing pressurized fluid to be discharged from the interior pumping chamber;   b) a cam ring disposed within the interior pumping chamber and defining a continuous peripheral cam surface;   c) rotor mounted for axial rotation within the interior pumping chamber and defining a pump axis;   d) a plurality of circumferentially spaced apart radially extending vanes mounted for radial movement within slots formed in the rotor, the plurality of vanes defining an equal number of circumferentially spaced apart volume chambers which extend between an outer periphery of the rotor and the cam surface for carrying pressurized fluid; and   e) axially opposed first and second wear disks disposed within the interior pumping chamber, the first wear disk having an outer periphery which is positioned radially inward of the cam surface and is adapted and configured to slide axially with respect to the cam surface, so as to provide for thermal expansion of the rotor and vanes, and the second wear disk being positioned adjacent to a second end surface of the rotor.   
     
     
         2 . A hydraulic vane pump as recited in  claim 1 , wherein the vane pump is a multi-discharge hydraulic vane pump and the pump body defines four radially-oriented discharge ports, each port allowing pressurized fluid to be discharged from the interior pumping chamber. 
     
     
         3 . A hydraulic vane pump as recited in  claim 1 , wherein the first wear disk is biased towards the first end surface of the rotor using a spring element towards the first end surface of the rotor. 
     
     
         4 . A hydraulic vane pump as recited in  claim 1 , wherein the first wear disk is biased towards the first end surface of the rotor using pressurized fluid discharged from the volume chambers defined by the vanes. 
     
     
         5 . A hydraulic vane pump as recited in  claim 1 , wherein the pump body further includes a rear housing plate and the inlet port extends axially through the rear housing plate to the interior chamber. 
     
     
         6 . A hydraulic vane pump as recited in  claim 1 , wherein the cam surface includes four quadrantal cam segments, wherein diametrically opposed cam segments have identical cam profiles, and each cam segment defines an inlet arc, a discharge arc and two seal arcs. 
     
     
         7 . A hydraulic vane pump as recited in  claim 6 , wherein the cam ring includes a plurality of inlet chambers arranged and configured to receive fluid from the inlet port and distribute the fluid to the inlet arc of each cam segment. 
     
     
         8 . A hydraulic vane pump as recited in  claim 6 , wherein the cam ring includes a plurality of discharge chambers which communicate with the discharge arc of each cam segment and are arranged and configured to facilitate the discharge of pressurized fluid from the interior pumping chamber. 
     
     
         9 . A hydraulic vane pump as recited in  claim 1 , wherein each vane slot has an under-vane pocket for receiving fluid and the pressure of the undervane pocket is dependent on an angular position of the rotor. 
     
     
         10 . A hydraulic vane pump as recited in  claim 9 , wherein the rotor includes a plurality of axially-extending under-vane passages, each under-vane passage communicating with an under-vane pocket through a connector passage. 
     
     
         11 . A hydraulic vane pump as recited in  claim 10 , wherein each wear disk includes flow passages for communicating fluid into the under-vane pockets and under-vane passages associated with each vane slot and the pressure of the undervane pocket is dependent on an angular position of the rotor. 
     
     
         12 . A hydraulic vane pump as recited in  claim 9 , wherein the pressure of the fluid in the rotor under-vane passage whilst positioned in the inlet arc segment is about equal to pump inlet pressure. 
     
     
         13 . A hydraulic vane pump as recited in  claim 9 , wherein the pressure of the fluid in the rotor under-vane passage whilst positioned in the discharge arc segment is about equal to pump discharge pressure. 
     
     
         14 . A hydraulic vane pump as recited in  claim 6 , further comprising a fluid metering system for extracting fluid flow from the discharge arcs of the four cam segments. 
     
     
         15 . A hydraulic vane pump as recited in  claim 14 , wherein the fluid metering system has a first operating condition in which fluid is extracted from the discharge arcs of all four cam segments and combined for delivery to a source of fluid demand. 
     
     
         16 . A hydraulic vane pump as recited in  claim 14 , wherein the fluid metering system has a second operating condition wherein fluid is extracted from a first pair of diametrically opposed discharge arcs for delivery to a source of fluid demand and fluid from a second pair of diametrically opposed discharge arcs bypasses the source of fluid demand and returns to the pumping chamber. 
     
     
         17 . A multi-discharge hydraulic vane pump, comprising:
 a) a pump body including an interior pumping chamber and defining a axially extending inlet port for allowing fluid to be provided to the interior pumping chamber and four discharge ports for allowing pressurized fluid to be discharged from the interior pumping chamber;   b) a cam ring disposed within the interior pumping chamber and defining a continuous peripheral cam surface;   c) rotor mounted for axial rotation within the interior pumping chamber and defining a pump axis;   d) a plurality of circumferentially spaced apart radially extending vanes mounted for radial movement within slots formed in the rotor, the plurality of vanes defining an equal number of circumferentially spaced apart volume chambers which extend between an outer periphery of the rotor and the cam surface for carrying pressurized fluid; and   e) axially opposed first and second wear disks disposed within the interior pumping chamber.   
     
     
         18 . A multi-discharge hydraulic vane pump as recited in  claim 17 , wherein the first wear disk has an outer periphery which is positioned radially inward of the cam surface and is mounted for sliding movement with respect to the cam surface, so as to provide for thermal expansion of the rotor and vanes, and the second wear disk being positioned adjacent to a second end surface of the rotor. 
     
     
         19 . A multi-discharge hydraulic vane pump as recited in  claim 18 , wherein the first wear disk is biased towards the first end surface of the rotor using a spring element towards the first end surface of the rotor. 
     
     
         20 . A multi-discharge hydraulic vane pump as recited in  claim 18 , wherein the first wear disk is biased towards the first end surface of the rotor using pressurized fluid discharged from the volume chambers defined by the vanes. 
     
     
         21 . A multi-discharge hydraulic vane pump as recited in  claim 17 , wherein the pump body further includes a rear housing plate and the inlet port extends axially through the side plate towards the interior chamber. 
     
     
         22 . A multi-discharge hydraulic vane pump as recited in  claim 17 , wherein the cam surface includes four quadrantal cam segments, wherein diametrically opposed cam segments have identical cam profiles, and each cam segment defines an inlet arc, a discharge arc and two seal arcs. 
     
     
         23 . A multi-discharge hydraulic vane pump as recited in  claim 17 , wherein the cam ring includes a plurality of inlet chambers arranged and configured to receive fluid from the inlet port and distribute the fluid to the inlet arc of each cam segment 
     
     
         24 . A multi-discharge hydraulic vane pump as recited in  claim 17 , wherein the cam ring includes a plurality of discharge chambers which communicate with the discharge arc of each cam segment and are arranged and configured to facilitate the discharge of pressurized fluid from the interior pumping chamber. 
     
     
         25 . A multi-discharge hydraulic vane pump as recited in  claim 17 , wherein each vane slot has an under-vane pocket for receiving fluid and the pressure in the undervane pocket is dependent on an angular position of the rotor. 
     
     
         26 . A multi-discharge hydraulic vane pump as recited in  claim 25 , wherein the rotor includes a plurality of axially-extending under-vane passages, each under-vane passage communicating with an under-vane pocket through a connector passage. 
     
     
         27 . A multi-discharge hydraulic vane pump as recited in  claim 26 , wherein each wear disk includes flow passages for communicating fluid into the under-vane pockets and under-vane passages associated with each vane slot based and the pressure of the undervane pocket is dependent on an angular position of the rotor. 
     
     
         28 . A multi-discharge hydraulic vane pump as recited in  claim 25 , wherein the pressurized fluid in the rotor under-vane pocket whilst positioned in the inlet arc segment is about equal to pump inlet pressure. 
     
     
         29 . A multi-discharge hydraulic vane pump as recited in  claim 25 , wherein the pressurized fluid in the rotor under-vane pocket whilst positioned in the discharge arc segment is about equal to pump discharge pressure. 
     
     
         30 . A multi-discharge hydraulic vane pump as recited in  claim 22 , further comprising a fluid metering system for extracting fluid flow from the discharge arcs of the four cam segments. 
     
     
         31 . A multi-discharge hydraulic vane pump as recited in  claim 30 , wherein the fluid metering system has a first operating condition in which fluid is extracted from the discharge arcs of all four cam segments and combined for delivery to a source of fluid demand. 
     
     
         32 . A multi-discharge hydraulic vane pump as recited in  claim 30 , wherein the fluid metering system has a second operating condition wherein fluid is extracted from a first pair of diametrically opposed discharge arcs for delivery to a source of fluid demand and fluid from a second pair of diametrically opposed discharge arcs bypasses the source of fluid demand and returns to the pumping chamber. 
     
     
         33 . A hydraulic vane pump, comprising:
 a) a pump body including an interior pumping chamber and defining an inlet port for allowing fluid to be provided to the interior pumping chamber and at least one discharge port for allowing pressurized fluid to be discharged from the interior pumping chamber;   b) a cam ring disposed within the interior pumping chamber and defining a continuous peripheral cam surface, the cam ring also defining a plurality of inlet chambers and discharge chambers, the inlet chambers being arranged and configured to receive fluid from the inlet port and to distribute the fluid to the interior pumping chamber, the discharge chambers communicating with the interior pumping chamber and are arranged and configured to facilitate the discharge of pressurized fluid from the interior pumping chamber;   c) a rotor mounted for axial rotation within the interior pumping chamber and defining a pump axis;   d) a plurality of circumferentially spaced apart radially extending vanes mounted for radial movement within slots formed in the rotor, the plurality of vanes defining an equal number of circumferentially spaced apart volume chambers which extend between an outer periphery of the rotor and the cam surface for carrying pressurized fluid, wherein each vane slot has an under-vane pocket for receiving pressurized fluid based on an angular position of the rotor; and   e) axially opposed first and second wear disks disposed within the interior pumping chamber, the first wear disk having an outer periphery which is positioned radially inward of the cam surface and is axially biased towards a first end surface of the rotor so as to provide for thermal expansion of the rotor and vanes and the second wear disk being positioned adjacent to a second end surface of the rotor.   
     
     
         34 . The hydraulic vane pump as recited in  claim 33 , wherein each wear disk includes flow passages for feeding fluid into the under-vane pockets associated with each vane slot and the pressure of the undervane pocket is dependent on an angular position of the rotor.