Control arrangement and method of controlling a transmission in a machine

• US 8,622,871 B2
• Filed: 12/20/2010
• Issued: 01/07/2014
• Est. Priority Date: 12/20/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Hoff, Brian D.
• Primary Examiner(s): PANG, ROGER L
• Application Number:
  US12/973,413
• Publication Number:
  US 20120157253A1
• Time in Patent Office: 1,114 Days
• Field of Search: 475/72, 475/80, 475/83, 477/3, 477/52, 477/68, 477/98, 701/62, 701/66, 746/65.A, 746/65.B, 747/301
• US Class Current: 477/68
• CPC Class Codes: B60W 2510/107 Temperature
• CPC Class Codes: F16H 2037/0886 with switching means, e.g. to change ranges
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 47/04 the mechanical gearing being of the type with members having orbital motion
• CPC Class Codes: F16H 61/439 Control of the neutral position, e.g. by zero tilt rotation holding means
• CPC Class Codes: Y10T 74/19037 One path includes fluid drive
• CPC Class Codes: Y10T 74/19074 Single drive plural driven

Abstract

The disclosure is directed to a method for use in a machine having a transmission having an operational mode, and including first and second power source paths, and a combined power output. The first power source path includes a variator. The method of controlling the transmission includes operating the first power source path, providing a signal indicative of the operational mode of the transmission to a controller, and at least partially neutralizing the variator if the signal indicates that the transmission is in neutral for at least a preset period of time.

Claims

1. In a machine comprising a transmission having an operational mode selector and including first and second power source paths, and a combined power output, the first power source path including a variator, a method of controlling the transmission comprising the steps of:

operating the first power source path;

providing a signal indicative of a selected operational mode of the transmission to a controller;

timing a length of time that the operational mode selector is in neutral;

determining if the variator has reached a preset temperature; and

at least partially neutralizing the variator if the signal indicates that the operational mode selector is in neutral for at least a preset period of time.

2. The method according to claim 1, wherein the preset period of time is at on the order of ten seconds.

3. The method according to claim 1, wherein the first power source path includes a pump and motor.

4. The method according to claim 3, wherein the first and second power source paths output to a planetary gear arrangement.

5. The method according to claim 3, wherein the neutralizing step includes reducing the output of the pump.

6. The method according to claim 5, wherein the preset period of time is on the order of ten seconds.

7. The method according to claim 5, wherein the reducing step includes adjusting a swash plate of the pump.

8. The method according to claim 7, wherein reduction in the output of the pump at least partially neutralizes the motor.

9. The method according to claim 8 wherein the adjusting step includes operation of an actuator to adjust the swash plate.

10. The method according to claim 1, wherein the timing step is performed by a controller.

11. The method according to claim 1, wherein the timing step is performed by a timer separate from a controller.

12. The method according to claim 1, further including the step of determining if a temperature difference across the variator has dropped to a preset value.

13. The method according to claim 1, wherein the first power source path includes at least one of the following:

an electric motor driving an electro-mechanical transmission, an electric battery and a motor, a hydraulic accumulator and a motor, and an electric generator and electric motor.

14. A control system in a variable transmission of a machine, the transmission having an operational mode, and having first and second power source paths, and a combined power output, the first power source path including a variator, the control system comprising:

a selectively adjustable operational mode selector adapted to supply a signal indicative of a selected operational mode;

a timer adapted to provide a signal indicative of time lapse;

at least one temperature sensor disposed to determine a temperature of the variator;

an actuator adapted to control an operative state of at least a portion of the variator; and

a controller in electrical communication with the actuator and adapted to receive the signal indicative of the selected operational mode and a signal indicative of the temperature of the variator, the controller being configured to determine if the variator has reached a preset temperature, the controller being configured to supply a signal to the actuator to at least partially neutralize at least a portion of the variator if the signal indicative of the selected operational mode indicates that the operational mode selector is in neutral for at least a preset period of time.

15. The control system according to claim 14, wherein the preset period of time is on the order of ten seconds.

16. The control system according to claim 14, wherein the first power source path includes a pump and a motor.

17. The control system according to claim 16 wherein the pump includes a swash plate disposed at an angle in the pump, and the actuator is disposed to control the angle of the swash plate.

18. A machine comprising

a transmission including

a first power source path including a variator including at least one of a pump and a motor;

a second power source path;

a combined power output from said first and second power source paths;

a selectively adjustable operational mode selector adapted to supply a signal indicative of a selected operational mode; and

an actuator adapted to control an operative state of at least a portion of the variator;

a timer adapted to provide a signal indicative of time lapse;

at least one temperature sensor disposed to determine a temperature of the variator, and

a controller in electrical communication with the actuator and adapted to receive the signal indicative of the selected operational mode and a signal indicative of the temperature of the variator, the controller being configured to determine if the variator has reached a preset temperature, the controller being configured to supply a signal to the actuator to at least partially neutralize at least a portion of the variator if the signal indicative of the selected operational mode indicates that the operational mode selector is in neutral for at least a preset period of time.

19. The machine according to claim 18, wherein the preset period of time is on the order of ten seconds, and the pump includes a swash plate disposed at an angle within the pump, the actuator being disposed to control the angle of the swash plate.