Valve assembly for machine fluid operations

Abstract

A system. The system includes a valve assembly. The valve assembly includes a first port, a second port fluidically couplable with the first port upon application of negative pressure at the first port, a third port fluidically couplable with the first port upon application of positive pressure at the first port, and a first check valve positioned between the first port and the second port. The system also includes a second check valve fluidically couplable with the third port upon the application of the positive pressure at the first port. The second check valve is positioned external to the valve assembly.

What is claimed is: 
     
         1 . A system, comprising:
 a valve assembly, wherein the valve assembly comprises:
 a first port; 
 a second port fluidically couplable with the first port upon application of negative pressure at the first port; 
 a third port fluidically couplable with the first port upon application of positive pressure at the first port; and 
 a first check valve positioned between the first port and the second port; and 
   a second check valve fluidically couplable with the third port upon the application of the positive pressure at the first port.   
     
     
         2 . The system of  claim 1 , wherein the second check valve is positioned between a filter and the third port. 
     
     
         3 . The system of  claim 1 , further comprising a first fluid line fluidically couplable with the valve assembly, wherein the first fluid line comprises:
 a first end proximate the second port; and   a second end proximate a fluid reservoir of a machine.   
     
     
         4 . The system of  claim 1 , further comprising a second fluid line fluidically couplable with the valve assembly, wherein the second fluid line comprises:
 a first end proximate the third port; and   a second end proximate the second check valve.   
     
     
         5 . The system of  claim 4 , wherein the second end of the second fluid line is further proximate a fluid filter of a machine. 
     
     
         6 . The system of  claim 5 , wherein the second fluid line is fluidically couplable with the fluid filter upon the application of the positive pressure at the first port. 
     
     
         7 . The system of  claim 1 , further comprising:
 a first fluid line fluidically couplable with the second port; and   a second fluid line fluidically couplable with the third port and the second check valve.   
     
     
         8 . The system of  claim 1 , further comprising a fluid component fluidically couplable with the first port, wherein the fluid component is positioned external to the valve assembly. 
     
     
         9 . The system of  claim 8 , wherein the fluid component is configured for generating at least one of the following:
 the positive pressure at the first port; and   the negative pressure at the first port.   
     
     
         10 . The system of  claim 1 , further comprising a coupling connected to at least one of the following:
 the first port;   the second port; and   the third port.   
     
     
         11 . A fluid system of a machine, the fluid system comprising:
 a fluid reservoir;   a pump coupled to the fluid reservoir;   a filter coupled to the pump, wherein the pump is configured to communicate fluid from the fluid reservoir to a component of the machine via the filter;   a valve assembly, wherein the valve assembly comprises:
 a first port; 
 a second port fluidically coupled to the first port upon application of negative pressure at the first port; 
 a third port fluidically coupled to the first port upon application of positive pressure at the first port; and 
 a first check valve positioned between the first port and the second port; and 
   a second check valve configured to selectively establish fluid communication between the filter and the third port.   
     
     
         12 . The fluid system of  claim 11 , wherein the second check valve is fluidically couplable with the third port upon the application of the positive pressure at the first port. 
     
     
         13 . The fluid system of  claim 11 , wherein a second fluid line is fluidically couplable with the filter upon the application of the positive pressure at the first port. 
     
     
         14 . The fluid system of  claim 11 , further comprising a fluid component fluidically couplable with the first port. 
     
     
         15 . The fluid system of  claim 14 , wherein the fluid component is configured for generating at least one of the following:
 the positive pressure at the first port; and   the negative pressure at the first port.   
     
     
         16 . The fluid system of  claim 11 , further comprising a coupling connected to at least one of the following:
 the first port;   the second port; and   the third port.   
     
     
         17 . A system, comprising:
 a valve assembly, wherein the valve assembly comprises:
 a first port; 
 a second port fluidically couplable with the first port upon application of negative pressure at the first port; 
 a third port fluidically couplable with the first port upon application of positive pressure at the first port; and 
 a first check valve positioned between the first port and the second port; and 
   a second check valve.   
     
     
         18 . The system of  claim 17 , wherein the second check valve is fluidically couplable with the third port upon the application of the positive pressure at the first port 
     
     
         19 . The system of  claim 17 , further comprising a filter and a pump, wherein the filter is coupled to the pump, and wherein the pump is configured to communicate fluid from a fluid reservoir to a component of a machine via the filter; 
     
     
         20 . The system of  claim 19 , wherein the second check valve is configured to selectively establish fluid communication between the filter and the third port.