Control system having variable-speed engine-drive fan

• US 8,869,523 B2
• Filed: 04/14/2011
• Issued: 10/28/2014
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Chadwick, Michael J., Johnson, Jared P., Hermann, Gregory G., Pusch, Thomas G.
• Primary Examiner(s): Lazo, Thomas E
• Application Number:
  US13/086,966
• Publication Number:
  US 20120260867A1
• Time in Patent Office: 1,293 Days
• Field of Search: 604/90, 609/12, 123/41.11, 123/41.12
• US Class Current: 60/490
• CPC Class Codes: F01P 7/044 using hydraulic drives

Abstract

A control system for use with a machine having an engine is disclosed. The control system may have a cooling circuit, a heat exchanger associated with the cooling circuit, and a sensor configured to generate a signal indicative of a temperature of the cooling circuit. The cooling system may also have a fan mechanically driven by the engine to direct air through the cooling circuit, and a controller in communication with the sensor and the engine. The controller may be configured to adjust a speed of the engine based on the signal.

Claims

1. A control system for a machine having an engine, comprising:

a cooling circuit;

a heat exchanger associated with the cooling circuit;

a sensor configured to generate a signal indicative of a temperature of the cooling circuit;

a fan mechanically driven by the engine to direct air through the heat exchanger; and

a controller in communication with the sensor and the engine, the controller configured to adjust a speed of the engine based on the signal by adjusting fueling of the engine by an amount related to a desired seed of the fan.

2. The control system of claim 1, wherein the fan rotates at a fixed ratio relative to the speed of the engine.

3. The control system of claim 1, wherein:

the machine includes a transmission driven by the engine to rotate a traction device; and

the controller is further configured to adjust the transmission to account for a change in travel speed caused by an adjustment in fueling of the engine implemented based on the signal.

4. The control system of claim 3, wherein:

the transmission is a hystat transmission; and

the controller is configured to adjust the transmission by adjusting a displacement of at least one of a pump and a motor of the transmission.

5. The control system of claim 3, wherein the controller is configured to:

determine an adjustment to the transmission required to account for the change in travel speed prior to implementing the adjustment in fueling; and

implement the adjustment to the transmission while adjusting fueling based on the signal to maintain a substantially constant travel speed during fuel adjusting.

6. The control system of claim 5, wherein:

the signal is a first signal;

the controller is configured to determine a first desired engine speed based on the first signal;

the controller is further configured to receive a second signal not associated with the sensor that is indicative of a second desired change in engine speed; and

the controller is configured to adjust the engine speed and determine the adjustment to the transmission based on a greater one of the first and second desired changes in engine speed.

7. A control system for a machine having a transmission driven by an engine to rotate a traction device, the control system comprising:

a sensor configured to generate a signal indicative of a desired change in engine speed; and

a controller in communication with the sensor and the engine, the controller being configured to;

determine, before implementation of the desired change in engine speed, an adjustment to the transmission based on the desired change in engine speed that maintains a substantially constant travel speed; and

implement the adjustment at about the same time as the desired change in engine speed.

8. The control system of claim 7, wherein the sensor is a temperature sensor.

9. The control system of claim 8, wherein the desired change in engine speed is associated with a speed change of a cooling fan that is mechanically driven by the engine.

10. The control system of claim 7, wherein the controller is configured to adjust the speed of the engine by adjusting fueling of the engine.

11. The control system of claim 7, wherein the controller is configured to adjust the transmission by adjusting a gear ratio of the transmission.

12. The control system of claim 11, wherein:

the transmission is a hystat transmission; and

the controller is configured to adjust the gear ratio by adjusting a displacement of at east one of a pump and a motor of the transmission.

13. The control system of claim 7, wherein:

the signal is a first signal;

the desired change in engine speed is a first desired change in engine speed;

the controller is further configured to receive a second signal not associated with the sensor that is indicative of a second desired change in engine speed; and

the controller is configured to determine the transmission adjustment based on the one of the first and second signals that is indicative of a greater desired change in engine speed.

14. A method of cooling a machine system, comprising:

generating a signal indicative of a temperature of the machine system;

determining a desired cooling fan speed change based on the signal;

determining an engine speed change required to produce the desired cooling fan speed change;

determining, prior to implementation of the engine speed change, a transmission adjustment required to maintain a substantially constant travel speed during implementation of the engine speed change; and

implementing the transmission adjustment at about the same time as the engine speed change.

15. The method of claim 14, wherein determining an engine speed change includes determining a change in engine fueling.

16. The method of claim 14, wherein determining a transmission adjustment includes determining a displacement adjustment of at least one of a transmission pump or motor.

17. The method of claim 14, wherein:

determining the engine speed change required to produce the desired cooling fan speed change includes determining a first engine speed change;

the method further includes determining a second engine speed change not associated with the desired cooling fan speed change;

determining the transmission adjustment includes determining the transmission adjustment required to maintain a substantially constant travel speed during implementation of a greater one of the first and second engine speed changes; and

the method further includes implementing the transmission adjustment at about the same time as the greater one of the first and second engine speed changes.

18. A machine, comprising:

an engine configured to produce a mechanical output;

a cooling circuit configured to circulate fluid through the engine;

a heat exchanger associated with the cooling circuit;

a fan mechanically driven by the engine to direct air through the heat exchanger;

a sensor configured to generate a signal associated with a temperature of the engine;

a traction device configured to receive a mechanical input and propel the machine;

a transmission fluidly connecting the mechanical output to the mechanical input, the transmission including;

a pump connected to the mechanical output of the engine; and

a motor configured to receive pressurized fluid from the pump and being connected to the mechanical input of the traction device; and

a controller in communication with the engine, the transmission, and the sensor, the controller being configured to;

determine a first desired speed change of the engine based on the signal;

determine a second desired speed change of the engine not associated with the signal;

determine, prior to implementation of the first or second desired speed changes, a transmission adjustment required to maintain a substantially constant travel speed during implementation of a greater one of the first and second desired speed changes; and

implement the transmission adjustment at about the same time as the greater one of the first and second desired speed changes.