High ambient temperature propulsion speed control of a self-propelled agricultural product applicator

• US 10,393,261 B2
• Filed: 12/06/2017
• Issued: 08/27/2019
• Est. Priority Date: 12/06/2017
• Status: Active Grant

• Current Assignee: CNH Industrial America LLC (CNH Industrial N.V.), Danfoss Power Solutions Inc. (Danfoss A/S)
• Original Assignee: CNH Industrial America LLC (CNH Industrial N.V.)
• Inventors: Hafvenstein, David J., Nielsen, Simon L.
• Primary Examiner(s): Nguyen, Tan Q
• Application Number:
  US15/833,089
• Publication Number:
  US 20190170247A1
• Time in Patent Office: 629 Days
• Field of Search: 701 50
• CPC Class Codes: A01C 23/00 Distributing devices specially adapted for liquid manure or other fertilising liquid, including ammonia, e.g. transport tanks or sprinkling wagons
• CPC Class Codes: A01M 21/04 Apparatus for destruction by steam, chemicals, burning, or electricity apparatus for burning A01M15/00
• CPC Class Codes: B60Y 2300/184 Preventing damage resulting from overload or excessive wear of the driveline
• CPC Class Codes: F16H 2061/1216 Display or indication of detected failures
• CPC Class Codes: F16H 2061/124 Limiting the input power, torque or speed
• CPC Class Codes: F16H 39/02 with liquid motors at a distance from liquid pumps
• CPC Class Codes: F16H 59/72 dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: F16H 61/4192 Detecting malfunction or potential malfunction, e.g. fail safe
• CPC Class Codes: F16H 61/42 involving adjustment of a pump or motor with adjustable output or capacity F16H61/46 takes precedence
• CPC Class Codes: F16H 61/47 for achieving a target output speed

Abstract

A system, apparatus and method are provided for limiting operating speed at high temperatures of a self-propelled, agricultural product applicator having a hydraulic drive system including a pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic motor operatively connected for propelling the applicator. A temperature sensor detects a temperature of the pressurized hydraulic fluid in the hydraulic system. A propel controller is operatively connected between the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to one or more predetermined de-rated conditions resulting in reduced motor speed, in accordance with a predetermined schedule, when predetermined motor de-rating activation temperature limits of the hydraulic fluid are detected by the temperature sensor. The controller is further configured for providing a de-rated condition warning signal prior to limiting displacement of the propulsion motor.

Claims

1. A system for limiting operating speed at high temperatures in a hydraulically-driven, self-propelled, agricultural product applicator having a hydraulic system including a pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic motor operatively connected for propelling the applicator, the system comprising:

a temperature sensor operatively connected for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system; and

a propel controller operatively connected to the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor.

2. The speed limiting system of claim 1, wherein the controller is further configured to provide a warning signal prior to limiting displacement of the propulsion motor, when a predetermined warning activation temperature limit of the hydraulic fluid is detected by the temperature sensor, with the warning activation temperature being lower than the motor de-rating activation temperature.

3. A system for limiting operating speed at high temperatures in a hydraulically-driven, self-propelled, agricultural product applicator having a hydraulic system including a pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic motor operatively connected for propelling the applicator, the system comprising:

a temperature sensor operatively connected for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system; and

a propel controller operatively connected between the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor;

wherein the propulsion motor includes a swashplate for controlling motor rotational speed as a function of swashplate angle, and the propel controller is operatively connected for limiting motor speed by limiting swashplate angle in the de-rated condition.

4. The speed limiting system of claim 3, wherein the propulsion motor operates at maximum speed when the swashplate angle and corresponding motor displacement are at minimum values, and the controller is operatively connected to control the swashplate angle at an angle greater than the minimum value of swashplate angle in the de-rated condition, to thereby limit operation of the propulsion motor to a speed less than the maximum speed of the motor whenever the controller is limiting the motor to operation in the de-rated condition.

5. A system for limiting operating speed at high temperatures in a hydraulically-driven, self-propelled, agricultural product applicator having a hydraulic system including a pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic motor operatively connected for propelling the applicator, the system comprising:

a temperature sensor operatively connected for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system; and

a propel controller operatively connected between the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor;

wherein the propel controller is further configured for maintaining the propulsion motor in the de-rated condition until the temperature sensor detects that the hydraulic fluid temperature has dropped to a predetermined motor de-rating de-activation temperature.

6. The speed limiting system of claim 5, wherein the controller is further configured for de-rating the propulsion motor according to a derating schedule having at least a first and a second de-rated condition with corresponding first and second reductions in displacement of the propulsion motor in response to a schedule of respective first and second motor de-rating activation and de-activation temperatures.

7. The speed limiting system of claim 6, wherein the controller is further configured to maintain the warning signal prior until a predetermined warning de-activation temperature limit of the hydraulic fluid is detected by the temperature sensor, with the warning de-activation temperature being lower than the warning activation temperature.

8. The speed limiting system of claim 5, wherein the controller is further configured to provide a warning signal prior to reducing displacement of the propulsion motor, when a predetermined warning activation temperature limit of the hydraulic fluid is detected by the temperature sensor, with the warning activation temperature being lower than the motor de-rating activation temperature.

9. The speed limiting system of claim 8, wherein the controller is configured for providing and maintaining the warning signal, and for reducing and maintaining propulsion motor displacement in accordance with a schedule of predetermined temperatures as determined by the temperature sensor, in which:

the controller sends the warning at a warning activation temperature, and maintains the warning until the temperature sensor detects that the hydraulic fluid has cooled to a warning de-activation temperature that is lower than the warning activation temperature;

the controller limits motor displacement to a first de-rated condition in a manner providing a first reduction in operating speed of the applicator at a first motor de-rating activation temperature that is higher than the warning activation temperature, and maintains the limited motor displacement in the first de-rated condition until the temperature sensor detects that the hydraulic fluid has cooled to a first motor de-rating de-activation temperature that is lower than the first motor de-rating activation temperature; and

the controller limits motor displacement to a second de-rated condition in a manner providing a second reduction in operating speed of the applicator at a second motor de-rating activation temperature that is higher than the first motor de-rating activation temperature, and maintains the limited motor displacement in the second de-rated condition until the temperature sensor detects that the hydraulic fluid has cooled to a second motor de-rating de-activation temperature that is lower than the second motor de-rating activation temperature.

10. A self-propelled, hydraulically-driven, agricultural product applicator having an engine and a hydrostatic drive system, the hydrostatic drive system including a propulsion pump driven by the engine at a fixed ratio of engine speed and supplying pressurized hydraulic fluid to a variable-displacement hydraulic propulsion motor operatively connected for propelling the applicator, and a system for limiting operating speed of the hydraulically-driven, self-propelled, agricultural product applicator at high temperatures, where the system for limiting speed at high temperatures comprises:

a temperature sensor operatively connected for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system; and

a propel controller operatively connected to the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor.

11. The agricultural product applicator of claim 10, wherein the controller is further configured to provide a warning signal prior to limiting displacement of the propulsion motor, when a predetermined warning activation temperature limit of the hydraulic fluid is detected by the temperature sensor, with the warning activation temperature being lower than the motor de-rating activation temperature.

12. A self-propelled, hydraulically-driven, agricultural product applicator having an engine and a hydrostatic drive system, the hydrostatic drive system including a propulsion pump driven by the engine at a fixed ratio of engine speed and supplying pressurized hydraulic fluid to a variable-displacement hydraulic propulsion motor operatively connected for propelling the applicator, and a system for limiting operating speed of the hydraulically-driven, self-propelled, agricultural product applicator at high temperatures, where the system for limiting speed at high temperatures comprises:

a temperature sensor operatively connected for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system; and

a propel controller operatively connected between the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor;

wherein the propel controller is further configured for maintaining the propulsion motor in the de-rated condition until the temperature sensor detects that the hydraulic fluid temperature has dropped to a predetermined motor de-rating de-activation temperature.

13. A self-propelled, hydraulically driven, agricultural product applicator having an engine and a hydrostatic drive system, the hydrostatic drive system including a propulsion pump driven by the engine at a fixed ratio of engine speed and supplying pressurized hydraulic fluid to a variable-displacement hydraulic propulsion motor operatively connected for propelling the applicator, and a system for limiting operating speed of the hydraulically-driven, self-propelled, agricultural product applicator at high temperatures, where the system for limiting speed at high temperatures comprises:

a temperature sensor operatively connected for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system; and

a propel controller operatively connected between the temperature sensor and the propulsion motor and configured for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor;

wherein the propulsion motor includes a swashplate for controlling motor rotational speed as a function of swashplate angle, and the propel controller is operatively connected for limiting motor speed by limiting swashplate angle in the de-rated condition.

14. The agricultural product applicator of claim 13, wherein the propulsion motor operates at maximum speed when the swashplate angle and corresponding motor displacement are at minimum values, and the controller is operatively connected to control the swashplate angle at an angle greater than the minimum value of swashplate angle in the de-rated condition, to thereby limit operation of the propulsion motor to a speed less than the maximum speed of the motor whenever the controller is limiting the motor to operation in the de-rated condition.

15. The agricultural product applicator of claim 14, wherein the applicator includes at least one additional pump operatively connected to be driven from the propulsion pump at a fixed ratio of propulsion pump speed, for supplying a fixed flow of pressurized hydraulic fluid to a non-propulsion hydraulic system of the applicator when the propel controller is operating the propulsion motor in a de-rated condition, and when the propel controller is operating the propulsion motor in a de-rated condition.

16. The agricultural product applicator of claim 15, wherein the controller is further configured for de-rating the propulsion motor according to a derating schedule having at least a first and a second de-rated condition with corresponding first and second reductions in displacement of the propulsion motor in response to a schedule of respective first and second motor de-rating activation and de-activation temperatures.

17. The agricultural product applicator of claim 16, wherein the controller is configured for providing a warning signal prior to limiting displacement of the propulsion motor, when a predetermined warning activation temperature limit of the hydraulic fluid is detected by the temperature sensor, and for reducing and maintaining propulsion motor displacement in accordance with a schedule of predetermined temperatures as determined by the temperature sensor, in which:

the controller sends the warning at a warning activation temperature, and maintains the warning until the temperature sensor detects that the hydraulic fluid has cooled to a warning de-activation temperature that is lower than the warning activation temperature;

the controller limits motor displacement to a first de-rated condition in a manner providing a first reduction in operating speed of the applicator at a first motor de-rating activation temperature that is higher than the warning activation temperature, and maintains the limited motor displacement in the first de-rated condition until the temperature sensor detects that the hydraulic fluid has cooled to a first motor de-rating de-activation temperature that is lower than the first motor de-rating activation temperature; and

the controller limits motor displacement to a second de-rated condition in a manner providing a second reduction in operating speed of the applicator at a second motor de-rating activation temperature that is higher than the first motor de-rating activation temperature, and maintains the limited motor displacement in the second de-rated condition until the temperature sensor detects that the hydraulic fluid has cooled to a second motor de-rating de-activation temperature that is lower than the second motor de-rating activation temperature.

18. A method for limiting operating speed at high temperatures in a hydraulically-driven, self-propelled, agricultural product applicator having a hydraulic system including a propulsion pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic propulsion motor operatively connected for propelling the applicator, the method comprising:

operatively connecting a temperature sensor for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system;

operatively connecting a propel controller to the temperature sensor and the propulsion motor and configuring the controller for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor; and

limiting displacement of the propulsion motor according to the predetermined de-rated condition resulting in reduced propulsion motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor.

19. A method for limiting operating speed at high temperatures in a hydraulically-driven, self-propelled, agricultural product applicator having a hydraulic system including a propulsion pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic propulsion motor operatively connected for propelling the applicator, the method comprising:

operatively connecting a temperature sensor for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system;

operatively connecting a propel controller between the temperature sensor and the propulsion motor and configuring the controller for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor; and

limiting displacement of the propulsion motor according to the predetermined de-rated condition resulting in reduced propulsion motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor;

wherein;

the propulsion motor includes a swashplate for controlling motor rotational speed as a function of swashplate angle, and the propel controller is operatively connected for limiting propulsion motor speed by limiting swashplate angle in the de-rated condition;

the propulsion motor operates at maximum speed when the swashplate angle and corresponding motor displacement are at minimum values, and the controller is operatively connected to control the swashplate angle at an angle greater than the minimum value of swashplate angle in the de-rated condition, to thereby limit operation of the propulsion motor to a speed less than the maximum speed of the motor whenever the controller is limiting the motor to operation in the de-rated condition; and

the method further includes, controlling the swashplate angle at an angle greater than the minimum value of swashplate angle in the de-rated condition, to thereby limit operation of the propulsion motor to a speed less than the maximum speed of the motor whenever the controller is limiting the motor to operation in the de-rated condition.

20. A method for limiting operating speed at high temperatures in a hydraulically driven self-propelled, agricultural product applicator having a hydraulic system including a propulsion pump supplying pressurized hydraulic fluid to a variable-displacement hydraulic propulsion motor operatively connected for propelling the applicator, the method comprising:

operatively connecting a temperature sensor for detecting a temperature of the pressurized hydraulic fluid in the hydraulic system;

operatively connecting a propel controller between the temperature sensor and the propulsion motor and configuring the controller for limiting displacement of the propulsion motor according to a predetermined de-rated condition resulting in reduced motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor; and

limiting displacement of the propulsion motor according to the predetermined de-rated condition resulting in reduced propulsion motor speed, when a predetermined motor de-rating activation temperature limit of the hydraulic fluid is detected by the temperature sensor;

wherein the controller is configured for providing and maintaining a warning signal, and for reducing and maintaining propulsion motor displacement in accordance with a schedule of predetermined temperatures as determined by the temperature sensor, the method further comprises performing at least one operation from the list of operations consisting of;

sending the warning signal at a warning activation temperature, and maintaining the warning until the temperature sensor detects that the hydraulic fluid has cooled to a warning de-activation temperature that is lower than the warning activation temperature;

limiting motor displacement to a first de-rated condition in a manner providing a first reduction in operating speed of the applicator at a first motor de-rating activation temperature that is higher than the warning activation temperature, and maintaining the limited motor displacement in the first de-rated condition until the temperature sensor detects that the hydraulic fluid has cooled to a first motor de-rating de-activation temperature that is lower than the first motor de-rating activation temperature; and

limiting motor displacement to a second de-rated condition in a manner providing a second reduction in operating speed of the applicator at a second motor de-rating activation temperature that is higher than the first motor derating activation temperature, and maintaining the limited motor displacement in the second de-rated condition until the temperature sensor detects that the hydraulic fluid has cooled to a second motor derating de-activation temperature that is lower than the second motor de-rating activation temperature.