Multi-piston pump and valve arrangement

Abstract

A multi-piston pump includes a housing defining a first plurality of N bores therein, where N is the number of bores in the first plurality. The first plurality of N bores is offset from one another. The housing defines a second plurality of N bores therein. The second plurality of N bores is offset from one another. Each bore of the second plurality of N bores is offset from a corresponding bore of the first plurality of N bores. A substantially straight cylindrical piston is disposed in each of said bores for reciprocal movement along a longitudinal axis therein. The pistons in the first plurality of N bores are operable to induce fluid flow in hydraulic fluid. The pistons in the second plurality

1 . A multi-piston pump comprising: 
 a housing defining a first plurality of N bores therein, where N is the number of bores in said first plurality, said first plurality of N bores being offset from one another, said housing defining a second plurality of N bores therein, said second plurality of N bores being offset from one another, each bore of said second plurality of N bores being offset from a corresponding bore of said first plurality of N bores; and    a non-stepped piston disposed in each of said bores for reciprocal movement along a longitudinal axis therein, said pistons in said first plurality of N bores being operable to induce fluid flow in a first hydraulic circuit, said pistons in said second plurality of N bores being operable to induce fluid flow in a second hydraulic circuit.    
   
   
       2 . The multi-piston pump of  claim 1  wherein said non-stepped piston includes a valve arrangement for controlling fluid flow in one of said first hydraulic circuit and said second hydraulic circuit.  
   
   
       3 . The multi-piston pump of  claim 2  wherein said valve arrangement includes a check valve.  
   
   
       4 . The multi-piston pump of  claim 2  wherein said non-stepped piston is between 5 mm and 6 mm.  
   
   
       5 . The multi-piston pump of  claim 1  further comprising a generally cylindrical sleeve disposed in each of said bores, said sleeve having a substantially straight cylindrical longitudinal cavity defined therein, wherein said non-stepped piston is a substantially straight cylindrical piston slidably disposed in said cavity.  
   
   
       6 . The multi-piston pump of  claim 5  further comprising a clinched gland sealingly securing said sleeve in said bore.  
   
   
       7 . The multi-piston pump of  claim 6  further comprising an outlet check valve formed between said sleeve and said clinched gland, where in said outlet check valve includes a valve ball and a deep ball seat formed in said sleeve.  
   
   
       8 . The multi-piston pump of  claim 1  wherein said first set of N bores are offset from one another by approximately 360/N degrees, said second set of N bores are offset from one another by approximately 360/N degrees, and each bore of said second set of N bores are offset from a corresponding bore of said first of N bores set by approximately 90/N degrees.  
   
   
       9 . The multi-piston pump of  claim 8  wherein N is three.  
   
   
       10 . A valve arrangement for controlling fluid flow in a hydraulic circuit comprising; 
 a main valve body suitable to form a portion of a multi-piston pump, said main valve body having a plurality of bores formed therein; and    first and second pluralities of non-stepped pistons disposed in said bores.    
   
   
       11 . The valve arrangement of  claim 10  wherein a generally cylindrical sleeve is disposed in each of said bores within said main valve body, each of said sleeves forming valve seat.  
   
   
       12 . The valve arrangement of  claim 10  wherein said valve seat forms a portion of high lift outlet check valve.  
   
   
       13 . A multi-piston pump comprising: 
 a housing defining a first set of N bores therein, where N is the number of bores in said first set, said first set of N bores being offset from one another, said housing defining a second set of N bores therein, said second set of N bores being offset from one another, each bore of said second set of N bores being offset from a corresponding bore of said first of N bores set; and    a non-stepped piston disposed in each of said bores for reciprocal movement along a longitudinal axis therein, said pistons in said first set of N bores being operable to induce fluid flow in a first hydraulic circuit, said pistons in said second set of N bores being operable to induce fluid flow in a second hydraulic circuit; and    a valve arrangement for controlling fluid flow in at least one of the first hydraulic circuit and the second hydraulic circuit, the valve arrangement including a main valve body suitable to form a portion of a multi-piston pump.    
   
   
       14 . A multi-piston pump comprising: 
 a housing defining a first plurality of N bores therein, where N is the number of bores in said first plurality, said first plurality of N bores being offset from one another, said housing defining a second plurality of N bores therein, said second plurality of N bores being offset from one another, each bore of said second plurality of N bores being offset from a corresponding bore of said first plurality of N bores; and    a non-stepped piston disposed in each of said bores for reciprocal movement along a longitudinal axis therein, said pistons in said first plurality of N bores being operable to induce fluid flow of hydraulic fluid, said pistons in said second plurality of N bores being operable to induce fluid flow of hydraulic fluid.