Hydraulic displacement control system

Patent metadata

Field	Value
Publication number	US-10087960-B2
Application number	US-201415033363-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Oct 29, 2013
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A load based pressure and flow control system including a variable displacement hydraulic motor and a flow control valve coupled with a motor inlet. A motor inlet pressure sensor is interposed between the variable displacement hydraulic motor and the flow control valve, the motor inlet pressure sensor configured to measure a motor inlet pressure at the motor inlet. An output sensor is coupled with a motor output of the variable displacement hydraulic motor and configured to measure an output characteristic of the variable displacement hydraulic motor. A displacement and flow controller of the system is configured to change displacement of the variable displacement hydraulic motor according to a pressure difference across the flow control valve between the measured motor inlet pressure and a hydraulic system pressure, and change a flow rate of hydraulic fluid through the flow control valve according to the measured output characteristic of the hydraulic motor.

First claim

The claimed invention is:

1. A hydraulic system comprising:
a hydraulic circuit including:
a first hydraulic load configured for communication with a hydraulic pump, the first hydraulic load having a first load high pressure characteristic and a first load low flow characteristic, and
a second hydraulic load configured for communication with the hydraulic pump, the second hydraulic load having an initial second load low pressure characteristic and an initial second load high flow characteristic with respect to the first hydraulic load, the second hydraulic load including a variable displacement hydraulic motor; and

a displacement and flow controller associated with the second hydraulic load, the displacement and flow controller configured to:
change displacement of the variable displacement hydraulic motor according to a pressure difference across a flow control valve between a hydraulic system pressure and a measured motor inlet pressure at a motor inlet of the variable displacement hydraulic motor,
change a flow rate of hydraulic fluid through the flow control valve according to a measured output characteristic of the hydraulic motor, and
wherein the change in displacement and the change in flow rate transform the initial second load low pressure and high flow characteristics into transformed second load high pressure and low flow characteristics nearer to the first load high pressure characteristic and the first load low flow characteristic.

2. The hydraulic system of claim 1 comprising a motor inlet pressure sensor coupled with the motor inlet and interposed between the variable displacement hydraulic motor and the flow control valve, the motor inlet pressure sensor configured to measure the motor inlet pressure at the motor inlet.

3. The hydraulic system of claim 2 comprising a system pressure sensor upstream from the flow control valve, the system pressure sensor configured to measure the hydraulic system pressure of the hydraulic system, and
wherein the displacement and flow controller is configured to change displacement according to the pressure difference across the flow control valve based on the measured hydraulic system pressure measured by the system pressure sensor and the measured motor inlet pressure.

4. The hydraulic system of claim 1 comprising a speed sensor coupled with a motor output of the variable displacement hydraulic motor, wherein the measured output characteristic includes rotational speed of the motor output and the speed sensor is configured to measure the rotational speed, and
wherein the displacement and flow controller is configured to change the flow rate of hydraulic fluid according to the measured rotation speed.

5. The hydraulic system of claim 1 , wherein an initial composite of the first load low flow characteristic and the second load high flow characteristic is greater than a final composite of a first load flow characteristic and the transformed second low flow characteristic.

6. A hydraulic system comprising:
a hydraulic circuit including:
a first hydraulic load configured for communication with a hydraulic pump, the first hydraulic load having a first load high pressure characteristic and a first load low flow characteristic, and
a second hydraulic load configured for communication with the hydraulic pump, the second hydraulic load having an initial second load low pressure characteristic and an initial second load high flow characteristic with respect to the first hydraulic load, the second hydraulic load including a variable displacement hydraulic motor; and

a displacement and flow controller associated with the second hydraulic load, the displacement and flow controller configured to:
change displacement of the variable displacement hydraulic motor according to a pressure difference across a flow control valve between a hydraulic system pressure and a measured motor inlet pressure at a motor inlet of the variable displacement hydraulic motor,
change a flow rate of hydraulic fluid through the flow control valve according to a measured output characteristic of the hydraulic motor, and
wherein the change in displacement and the change in flow rate transform the initial second load low pressure and high flow characteristics into a transformed second load high pressure characteristic near to the hydraulic system pressure and a transformed second load low flow characteristic less than the initial second load high flow characteristic.

7. The hydraulic system of claim 6 , wherein the first hydraulic load includes at least one coulter downforce cylinder and piston assembly.

8. The hydraulic system of claim 6 , wherein the second hydraulic load includes a seeder fan coupled with a motor output of the variable displacement hydraulic motor.

9. The hydraulic system of claim 6 , wherein the variable displacement hydraulic motor includes a plurality of variable displacement hydraulic motors and tools coupled with each of the motor outputs of the plurality of variable displacement hydraulic motors.

10. The hydraulic system of claim 6 comprising a motor inlet pressure sensor coupled with the motor inlet and interposed between the variable displacement hydraulic motor and the flow control valve, the motor inlet pressure sensor configured to measure the motor inlet pressure at the motor inlet.

11. The hydraulic system of claim 10 comprising a system pressure sensor upstream from the flow control valve, the system pressure sensor configured to measure the hydraulic system pressure of the hydraulic system, and
wherein the displacement and flow controller is configured to change displacement according to the pressure difference across the flow control valve based on the measured hydraulic system pressure measured by the system pressure sensor and the measured motor inlet pressure.

12. The hydraulic system of claim 6 comprising a speed sensor coupled with a motor output of the variable displacement hydraulic motor, wherein the measured output characteristic includes rotational speed of the motor output and the speed sensor is configured to measure the rotational speed, and
wherein the displacement and flow controller is configured to change the flow rate of hydraulic fluid according to the measured rotation speed.

13. The hydraulic system of claim 6 , wherein an initial composite of the first load low flow characteristic and the second load high flow characteristic is greater than a final composite of a first load flow characteristic and the transformed second low flow characteristic.

14. The hydraulic system of claim 6 , wherein a system pressure of the hydraulic system is substantially equal to the first load high pressure characteristic with the second hydraulic load having either of the initial second load low pressure characteristic or the transformed second load high pressure characteristic.

15. A load based pressure and flow control system comprising:
a variable displacement hydraulic motor including a motor inlet and a motor outlet;
a flow control valve coupled with the motor inlet;
a motor inlet pressure sensor interposed between the variable displacement hydraulic motor and the flow control valve, the motor inlet pressure sensor configured to measure a motor inlet pressure at the motor inlet;
an output sensor coupled with a motor output of the variable displacement hydraulic motor, the output sensor configured to measure an output characteristic of the variable displacement hydraulic motor; and
a displacement and flow controller, the displacement and flow controller configured to:
change displacement of the variable displacement hydraulic motor accordin

Assignees

• Raven Ind Inc

Inventors

• Wagers Jesse

Classifications

• F16H61/4008

  Control of circuit pressure · CPC title

• F16H61/421 Primary

  Motor capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title

• F16H61/46

  Automatic regulation in accordance with output requirements · CPC title

• F15B15/088

  the motor using combined actuation, e.g. electric and fluid actuation · CPC title

• F16H61/4061

  Control related to directional control valves, e.g. change-over valves, for crossing the feeding conduits · CPC title