Transmission internal PTO clutch and method of control

Patent metadata

Field	Value
Publication number	US-10071720-B2
Application number	US-201615054548-A
Country	US
Kind code	B2
Filing date	Feb 26, 2016
Priority date	Feb 24, 2016
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A method of selectively controlling a power take-off (PTO) assembly includes positioning a clutch assembly radially between a shaft and a PTO gear, operably controlling the clutch assembly with a controller, and selectively engaging the clutch assembly with the controller. The controller monitors signals received from a plurality of sensors and compares the monitored signals with respective signal thresholds. The clutch assembly is engaged when the compared monitored signals are within the signal thresholds.

First claim

The invention claimed is:

1. A method of selectively controlling a power take-off (PTO) assembly, comprising:
positioning a clutch assembly radially between a shaft and a PTO gear;
operably controlling the clutch assembly with a controller;
selectively engaging the clutch assembly with the controller;
wherein the selectively engaging the clutch assembly step comprises:
monitoring, by the controller, signals received from a plurality of sensors;
comparing, by the controller, the monitored signals with respective signal thresholds; and
engaging the clutch assembly when the compared monitored signals are within the signal thresholds;

further wherein, the monitoring signals received from the plurality of sensors step comprises monitoring, by the controller, an engine speed sensor, a user input sensor, and a PTO output speed sensor.

2. The method of claim 1 , further wherein the monitoring signals received from the plurality of sensors step comprises monitoring, by the controller, a transmission range sensor, a vehicle speed sensor, a code sensor, a transmission temperature sensor, a vehicle grade sensor, and a line pressure sensor.

3. The method of claim 1 , further comprising:
comparing, by the controller, a user input signal generated by the user input to a user input threshold;
wherein, when the user input signal is within the user input threshold, the PTO clutch assembly is engaged;
wherein, when the user input signal is not within the user input threshold, the PTO clutch assembly is not engaged.

4. The method of claim 1 , further comprising comparing, by the controller, an engine speed indicated by the engine speed sensor to a PTO speed indicated by the PTO output speed sensor when the clutch assembly is in the engaged position, wherein the controller selectively disengages the clutch when the PTO speed is not within a threshold range relative to the engine speed.

5. The method of claim 1 , further wherein the controller does not engage the clutch assembly when a vehicle speed sensor indicates the vehicle speed within a vehicle speed range.

6. A method of controlling a power take-off (PTO) assembly of a transmission, comprising:
providing a user input, an engine, the transmission including a shaft, a hydraulic system, and fluid within the hydraulic system having a line pressure, a controller including a memory unit and a processor, and the PTO assembly including a PTO gear, a PTO output sensor, and a clutch assembly positioned between the PTO gear and the shaft;
determining, by the controller, when a user input has been received;
comparing, by the controller, the line pressure of the fluid to a pressure threshold stored in the memory after the user input has been received;
engaging the clutch assembly, by the controller, when the line pressure is above the pressure threshold;
detecting PTO speed with the PTO output sensor; and
comparing, by the controller, an engine speed of the engine to the PTO speed when the clutch assembly is engaged;
wherein, if a difference between engine speed and PTO speed is not within a predefined speed threshold value, the controller increases the line pressure.

7. The method of claim 6 , further comprising increasing engine speed if the line pressure is below the pressure threshold.

8. The method of claim 6 , wherein the engaging the clutch assembly step comprises opening a valve of the transmission.

9. The method of claim 6 , further wherein the controller compares the line pressure to a second pressure threshold stored in the memory, wherein when the line pressure is greater than the second pressure threshold, the controller modulates the valve in the transmission until the line pressure is less than the second pressure threshold.

10. The method of claim 6 , further comprising increasing the engine speed, by the controller, when clutch assembly is in the engaged position and the PTO speed is less than a PTO threshold.

11. The method of claim 6 , further wherein:
the controller compares the engine speed to an engine speed threshold stored in the memory of the controller; and
the controller disengages the clutch assembly if the monitored engine speed is greater than the engine speed threshold.

12. A method for controlling a power take-off (PTO) assembly of a transmission, comprising:
providing a controller, a user input, a pressure sensor, a valve, a shaft speed sensor, and the PTO assembly including a PTO gear, a PTO speed sensor and a clutch assembly disposed radially between the PTO gear and a shaft of the transmission;
receiving, with the controller, a command from the user input indicating a desired engagement of the clutch assembly;
comparing a line pressure detected by the pressure sensor to a pressure threshold stored in the controller;
controlling the valve, with the controller, to restrict the clutch assembly from engaging the PTO gear when the line pressure is less than the pressure threshold;
comparing a PTO speed measured by the PTO speed sensor to a shaft speed measured by the shaft speed sensor with the controller when the clutch assembly is in an engaged position; and
disengaging the clutch, with the controller, when the comparing a PTO speed step indicates the PTO speed is not substantially the same as the shaft speed.

13. The method for controlling a clutch assembly of claim 12 , further comprising controlling, with the controller, an input speed and increasing the input speed when the line pressure is less than the pressure threshold and the input speed is less than an input speed threshold.

14. The method of controlling a clutch assembly of claim 12 , further comprising increasing the line pressure when the shaft speed is greater than the PTO speed.

15. The method of controlling a clutch assembly of claim 12 , further comprising reducing the line pressure when the line pressure is above a second pressure threshold.

16. The method of controlling a clutch assembly of claim 12 , further comprising restricting the clutch assembly from engaging unless a transmission range selector is within a transmission range threshold.

17. The method of controlling a clutch assembly of claim 12 , further comprising:
providing a vehicle grade sensor that communicates the grade of the vehicle to the controller; and
restricting the clutch assembly from engaging when a vehicle grade sensor value is not within a vehicle grade threshold.

18. The method of controlling a clutch assembly of claim 12 , further comprising:
monitoring a transmission temperature;
providing an instantaneous full line pressure to engage the clutch assembly when the transmission temperature satisfies a temperature threshold; and
providing a gradual increase to line pressure to engage the clutch assembly when the transmission temperatures does not satisfy the temperature threshold.

19. The method of controlling a clutch assembly of claim 12 , further comprising:
monitoring an outrigger; and

engaging the clutch assembly only when the outrigger is in an extended position.

20. A method of selectively controlling a power take-off (PTO) assembly, comprising:
positioning a clutch assembly radially between a shaft and a PTO gear;
operably controlling the clutch assembly with a controller;
selectively engaging the clutch assembly with the controller;
wherein the selectively engaging the clutch assembly step comprises:
monitoring, by the controller, signals received from a plurality of sensors;
comparing, by the controller, the monitored signals with respective signal

Assignees

• Allison Transm Inc

Inventors

• Foster Michael
• Burchett Douglas

Classifications

• B60Y2300/1888

  Control of power take off [PTO] · CPC title

• B60Y2400/795

  Power take off · CPC title

• F16H2200/0004

  comprising a power take off shaft · CPC title

• B60W2540/215

  Selection or confirmation of options · CPC title

• B60K17/02 Primary

  characterised by arrangement, location, or kind of clutch · CPC title