Fixed displacement hydraulic pump match flow demand control system

1 . A fixed displacement hydraulic pump match flow demand control system, the system comprising:

a spool valve, the spool valve including,

a housing having a chamber including a first end and a second end, the housing having a plurality of input ports, each input port passing through the housing into the chamber, the housing further having a plurality of output ports, each output port passing from the chamber through the housing, the housing further having a control port passing through the housing to the first end of the chamber and at least one feedback port between the second end of the chamber and a load, and

a spool located within the chamber having a first end and second end, the spool configured to shuttle within chamber based at least in part on a pressure difference between the first end and the second end of the chamber, the spool including a plurality of blocking sections configured to block at least a portion of at least one of the output ports based on a spool location within the chamber, the spool further including at least one connection section coupled to space the plurality of the blocking sections;

a plurality of fixed displacement pumps, a fluid flow from each fixed displacement pump of the plurality of fixed displacement pumps in fluid communication with an associated input port of the plurality of input ports of the housing of the spool valve;

at least one return passage in fluid communication with at least one output port of the plurality of output ports of the spool valve;

a line feedback passage in fluid communication with the at least one feedback port and the load, line pressure from the line feedback passage generating a line pressure force on the second end of the spool within the chamber; and

a control valve in fluid communication with the control port of the spool valve, the control valve configured to provide a select bias pressure that generates a select bias force on the first end of the spool within the chamber to adjust a location of the spool in the chamber to achieve a desired line pressure.

2 . The system of claim 1 , further comprising:

a check valve positioned within a line passage between one of the fixed displacement pumps and the load.

3 . The system of claim 1 , further comprising:

at least one line passage, each line passage of the at least one line passage being in fluid communication with an associated one of the plurality of output ports of the spool valve.

4 . The system of claim 1 , further comprising:

a controller configured to control the control valve.

5 . The system of claim 4 , further comprising:

a pilot regulating valve in communication with the control valve to regulate variable line pressure to a constant value used by the control valve.

6 . The system of claim 4 , wherein the controller controls an electric solenoid.

7 . The system of claim 5 , further comprises:

at least one sensor configured to monitor conditions of the load, the controller configured to control the control valve based on an output of the at least one sensor.

8 . The system of claim 1 , wherein the control valve is a linear solenoid valve.

9 . The system of claim 1 , wherein the blocking sections of the spool are configured to continuously block individual pump flow from passing to the at least one return passage as the spool shuttles in the chamber.

10 . The system of claim 1 , further comprising at least one of:

a reserve tank in fluid communication with at least one output port of the plurality of output ports of the housing of the spool valve.

11 . A fixed displacement hydraulic pump match flow demand control system, the system comprising:

a spool valve, the spool valve including,

a housing having a chamber including a first end and a second end, the housing having a plurality of input ports, each input port passing through the housing into the chamber, the housing further having a plurality of output ports, each output port passing from the chamber through the housing, the housing further having a control port passing through the housing to the first end of the chamber and at least one feedback port between the second end of the chamber and a load, and

a spool located within the chamber having a first end and second end, the spool configured to shuttle within chamber based at least in part on a pressure difference between the first end and the second end of the chamber, the spool including a plurality of blocking sections configured to block at least a portion of at least one of the output ports based on a spool location within the chamber, the spool further including at least one connection section coupled to space the plurality of the blocking sections;

a plurality of fixed displacement pumps, a fluid flow from each fixed displacement pump of the plurality of fixed displacement pumps in fluid communication with an associated input port of the plurality of input ports of the housing of the spool valve;

at least one return passage in fluid communication with at least one output port of the plurality of output ports of the spool valve;

a control valve in fluid communication with the control port of the spool valve, the control valve configured to provide a select bias pressure that generates a select bias force on the first end of the spool within the chamber to adjust a location of the spool in the chamber to achieve a desired line pressure at one or more output ports of the plurality of output ports; and

a check valve positioned within a line passage between one of the fixed displacement pumps and a load.

12 . The system of claim 11 , further comprising:

a line feedback passage in fluid communication between the feedback port and the load, line pressure from the line feedback passage generating a line pressure force on the second end of the spool within the chamber.

13 . The system of claim 11 , further comprising:

a controller configured to control the control valve.

14 . The system of claim 13 , further comprising:

a pilot regulating valve in communication with the control valve to regulate variable line pressure to a constant value used by the control valve.

15 . The system of claim 13 , wherein the controller controls an electric solenoid.

16 . The system of claim 14 , further comprises:

at least one sensor configured to monitor conditions of the load, the controller configured to control the control valve based on an output of the at least one sensor.

17 . The system of claim 11 , wherein the control valve is a linear solenoid valve.

18 . The system of claim 11 , further comprising at least one of:

a reserve tank in fluid communication with at least one output port of the plurality of output ports of the housing of the spool valve.