Cylinder barrel

Abstract

In accordance with at least one aspect of this disclosure, a system comprises, a cylinder barrel configured to rotate within a pump housing. In embodiments, the cylinder barrel includes a main cylindrical body, a center recess defined within the main cylindrical body configured to seat a drive shaft therein, and a plurality of bores defined in the main cylindrical body, extending in an axial direction, wherein the plurality of bores are spaced apart circumferentially relative to one another about the main cylindrical body radially outward of the center recess. Each of the plurality of bores are configured to seat a respective piston therein and allow fluid flow therethrough. In embodiments, the main cylindrical body is of silicon nitride.

1 . A system, comprising:
 a pump having a pump housing;   a cylinder barrel configured to rotate within the pump housing, the cylinder barrel including:
 a main cylindrical body; 
 a center recess defined within the main cylindrical body configured to seat a drive shaft therein; and 
 a plurality of bores defined in the main cylindrical body, extending in an axial direction, wherein the plurality of bores are spaced apart circumferentially relative to one another about the main cylindrical body radially outward of the center recess, and wherein the plurality of bores are each configured to seat a respective piston therein and allow fluid flow therethrough, 
 wherein the main cylindrical body is formed of silicon nitride, wherein each respective piston further includes a ring disposed at an end thereof configured to form a hydrodynamic seal with an inner surface of a respective bore, wherein the ring is made of tool steel. 
   
     
     
         2 - 4 . (canceled) 
     
     
         5 . The system of  claim 1 , wherein a friction coefficient between the ring and the inner surface of the bore is about 0.11. 
     
     
         6 . The system of  claim 1 , wherein the pump is or includes a piston pump. 
     
     
         7 . The system of  claim 6 , wherein the piston pump is or includes a bent axis variable displacement piston pump. 
     
     
         8 . The system of  claim 1 , wherein the plurality of bores includes at least 7 bores. 
     
     
         9 . The system of  claim 8 , wherein the plurality of bores includes up to 13 bores. 
     
     
         10 . A method comprising:
 forming a silicon nitride cylinder barrel of a piston pump including;
 forming a main cylindrical body; 
 forming a center recess configured to seat a drive shaft therein; and 
 forming a plurality of bores each extending in an axial direction through the main cylindrical body, the plurality of bores forming a pattern disposed circumferentially about the main cylindrical body radially outward of the center recess, configured to seat a respective piston therein and allow fluid flow therethrough; 
   installing the cylinder barrel into the piston pump;   installing a respective piston tool steel ring onto each respective piston; and   installing the respective pistons into a respective bore of the plurality of bores.   
     
     
         11 . (canceled) 
     
     
         12 . The method of  claim 10 , further comprising, operating the piston pump. 
     
     
         13 . The method of  claim 12 , wherein, during operation of the piston pump, the plurality of bores remain substantially the same diameter throughout the life of the cylinder barrel.