Wear-resistant port plate for a fluid transfer device and fluid transfer device including same

Abstract

In a fluid transfer device ( 10 ) that includes a housing ( 12 ), a rotor ( 16 ) rotatably mounted in the housing ( 12 ) and having a bore ( 24 ) and at least one piston ( 30 ) slidingly mounted in the bore ( 24 ), a port plate ( 42 ) that includes a body portion ( 44 ) mountable in the housing ( 12 ) and formed from a first material and a wear layer ( 56 ) formed of a second material, different from the first material, attached to the body portion ( 44 ) and adapted to contact the rotor ( 16 ). Also a fluid transfer device ( 10 ) including such a port plate ( 42 ).

1 . A port plate for a fluid transfer device comprising a housing, a rotor rotatably mounted in the housing and having a bore and at least one piston slidably mounted in the bore, the port plate comprising: 
 a body portion mountable in the housing and formed from a first material; and    a wear layer formed from a second material, different from said first material, attached to said body portion and adapted to contact the rotor.    
   
   
       2 . The port plate of  claim 1  wherein said first material comprises a metal and said second material is selected from the group consisting of a ceramic, a cermet, ceramic matrix composites and metal matrix composites.  
   
   
       3 . The port plate of  claim 2  wherein said body portion includes a fluid inlet and a fluid outlet and the wear layer includes a first through-opening aligned with said fluid inlet and a second through-opening aligned with said fluid outlet.  
   
   
       4 . The port plate of  claim 2  further comprising an interlayer including a braze layer between said wear layer and said body portion.  
   
   
       5 . The port plate of  claim 4  wherein said braze layer comprises a silver alloy braze.  
   
   
       6 . The port plate of  claim 4  wherein said interlayer includes a layer of nickel and a layer of molybdenum.  
   
   
       7 . The port plate of  claim 2  wherein said wear layer has a thickness of about 0.1 inches.  
   
   
       8 . The port plate of  claim 2  wherein said wear layer is selected from the group consisting of silicon nitride, tungsten-carbide cobalt, silicon carbide, aluminum oxide and titanium carbide particulate-silicon carbide whisker-reinforced aluminum oxide.  
   
   
       9 . The port plate of  claim 2  wherein said metal comprises titanium, a titanium alloy, or steel.  
   
   
       10 . A fluid transfer device comprising: 
 a housing having an interior;    a cam surface in said interior;    a port plate in said interior opposite said cam surface comprising a body portion formed from a first material and a wear layer formed from a second material;    a rotor mounted in said housing for rotation relative to said housing and said port plate, said rotor including at least one axial opening and having a surface contacting said port plate wear layer; and    at least one piston mounted in said at least one opening and having a first end contacting said cam surface, said piston reciprocating in said at least one opening as said rotor rotates relative to said port plate.    
   
   
       11 . The fluid transfer device of  claim 10  wherein said rotor is axially fixed relative to said housing.  
   
   
       12 . The fluid transfer device of  claim 11  wherein said port plate is movable in a direction normal to said wear layer.  
   
   
       13 . The fluid transfer device of  claim 10  wherein said first material comprises a metal and said second material is selected from the group consisting of a ceramic, a cermet, a ceramic matrix composite and a metal matrix composite.  
   
   
       14 . The fluid transfer device of  claim 13  wherein said first material has a thickness of 0.1 inches.  
   
   
       15 . The fluid transfer device of  claim 13  including a layer of brazing material between said first material and said second material.  
   
   
       16 . The fluid transfer device of  claim 10  wherein said first material is selected from the group consisting of silicon nitride, tungsten-carbide cobalt, silicon carbide, aluminum oxide and titanium carbide particulate-silicon carbide whisker-reinforced aluminum oxide.  
   
   
       17 . The fluid transfer device of  claim 13  including an interlayer connecting said wear layer to said body portion, said interlayer comprising a silver alloy.  
   
   
       18 . The fluid transfer device of  claim 12  including at least one balance piston biasing said port plate against said rotor.  
   
   
       19 . A fluid transfer device comprising: 
 a housing having an interior;    a cam plate in said interior;    a floating port plate in said interior opposite said cam surface comprising a body portion formed from a first material and having a fluid inlet and a fluid outlet, a wear layer formed from a second material having a first through-opening aligned with said fluid inlet and a second through-opening aligned with said fluid outlet, and an interlayer including a silver alloy connecting said wear layer to said body portion;    a rotor mounted in said housing for rotation relative to said housing and said port plate, said rotor including at least one axial opening and having a surface contacting said port plate wear layer;    at least one piston mounted in said at least one opening and having a first end contacting said cam surface, said piston reciprocating in said at least one opening as said rotor rotates relative to said cam surface; and    biasing means biasing said port plate against said rotor.