System for distributing particulate material from an agricultural machine

1. A system for distributing particulate material from an agricultural machine, the system comprising:

a fan configured to provide an airflow in a supply line for distributing particulate material;

a hydraulic system configured to drive the fan at a plurality of fan speeds, the hydraulic system comprising:

a hydrostatic drive arrangement including a variable axial piston pump; and

a control system configured to control the hydraulic system, the control system executing a program stored in a non-transient medium operable to:

determine a given product application rate for distributing the particulate material;

determine a given ground speed of the agricultural machine;

determine a fan speed for achieving the given product application rate at the given ground speed; and

control the hydraulic system to drive the fan at the fan speed.

2. The system of claim 1 , further comprising a solenoid configured to control displacement of the variable axial piston pump, wherein the control system controls the hydraulic system via a Pulse Width Modulation (PWM) signal to the solenoid.

3. The system of claim 1 , further comprising an engine configured to drive the hydraulic system at a plurality of engine speeds, wherein the hydraulic system is operable to drive the fan at the plurality of fan speeds independently from the engine driving the hydraulic system at the plurality of engine speeds.

4. The system of claim 1 , wherein the product application rate is determined from a prescription map.

5. The system of claim 1 , further comprising a Human Machine Interface (HMI) in communication with the control system, wherein the product application rate is determined from input from the HMI.

6. The system of claim 1 , wherein the ground speed is determined from a vehicle speed sensor or Global Positioning System (GPS).

7. The system of claim 1 , wherein the control system determines the fan speed by referencing a data structure correlating a plurality of fan speeds to a plurality of ground speeds at a given product application rate.

8. The system of claim 7 , wherein the plurality of fan speeds is correlated to the plurality of ground speeds according to a predetermined configuration of the agricultural machine including a length and a diameter of the supply line.

9. The system of claim 7 , wherein the data structure comprises a look up table.

10. The system of claim 1 , wherein the hydraulic system further comprises:

a hydraulic motor configured to be driven by the variable axial piston pump of the hydrostatic drive arrangement.

11. A system for distributing particulate material from an agricultural machine, the system comprising:

a fan configured to provide an airflow in a supply line for distributing particulate material;

a hydraulic system configured to drive the fan at a plurality of fan speeds, the hydraulic system comprising:

a hydraulic motor;

a hydrostatic drive arrangement including a variable axial piston pump configured to drive the hydraulic motor;

a solenoid configured to control displacement of the variable axial piston pump; and

a control system configured to control the hydraulic system, the control system executing a program stored in a non-transient medium operable to:

determine a given product application rate for distributing the particulate material;

determine a given ground speed of the agricultural machine;

determine a fan speed for achieving the given product application rate at the given ground speed; and

control the hydraulic system via a Pulse Width Modulation (PWM) signal to the solenoid to drive the fan at the fan speed.