Dual clutch control system for integral torque converter and retarder and method thereof

Patent metadata

Field	Value
Publication number	US-10975960-B2
Application number	US-201916392140-A
Country	US
Kind code	B2
Filing date	Apr 23, 2019
Priority date	Apr 24, 2018
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A transmission system includes a fluid-coupling device, an electro-hydraulic control system, and a clutch. The fluid-coupling device includes an input coupled to an impeller, an output coupled to a turbine, and a stator disposed between the impeller and the turbine. The electro-hydraulic control system includes a flow valve disposed in fluid communication with the input and the output of the fluid-coupling device that is movable between at least a first position and a second position, at least one trim valve system fluidly coupled to the flow valve, and a solenoid disposed in fluid communication with the flow valve that is electrically controllable between an energized state and a de-energized state. The clutch is disposable in fluid communication with the flow valve and controllable between an applied position and an unapplied position.

First claim

The invention claimed is:

1. A transmission system comprising:
a fluid-coupling device coupled between a drive unit and a transmission, the fluid-coupling device including an input coupled to an impeller, an output coupled to a turbine, and a stator disposed between the impeller and the turbine;
an electro-hydraulic control system configured to distribute hydraulic fluid to a plurality of friction devices, the electro-hydraulic control system including a flow valve disposed in fluid communication with the input and the output of the fluid-coupling device that is movable between at least a first position and a second position, at least one trim valve system fluidly coupled to the flow valve, and a solenoid disposed in fluid communication with the flow valve that is electrically controllable between an energized state and a de-energized state;
a clutch disposable in fluid communication with the flow valve, the clutch being controllable between an applied position and an unapplied position; and
a control circuit disposed in electrical communication with the at least one trim valve system and the solenoid, the control circuit configured to control operation of the solenoid between the energized state and the de-energized state,
wherein when the solenoid is controlled in the energized state by the control circuit, the flow valve is disposed in the second position such that the flow valve is de-coupled from the clutch and the clutch is in the unapplied position,
wherein when the solenoid is controlled in the de-energized state by the control circuit, the flow valve is disposed in the first position such that the flow valve is fluidly coupled to the clutch and the clutch is in the applied position,
and wherein when the clutch is in the applied position, the clutch resists rotation of the stator.

2. The transmission of claim 1 , wherein when the clutch is in the unapplied position, the stator is free to rotate.

3. The transmission system of claim 1 , wherein the clutch is internally disposed in the fluid-coupling device and the fluid-coupling device includes a second clutch disposable in fluid communication with the flow valve.

4. The transmission system of claim 3 , wherein the second clutch is controllable between an applied position, in which the second clutch couples the impeller and the turbine to one another for rotation at approximately the same speed, and an unapplied position, in which the impeller and the turbine are not coupled to one another by the second clutch for rotation at approximately the same speed.

5. The transmission system of claim 4 , wherein the flow valve is a multiplexing valve that allows operation of only one of the clutch and the second clutch in the applied position at any one time.

6. The transmission system of claim 5 , wherein when the flow valve is disposed in the first position, the second clutch is in the unapplied position.

7. The transmission system of claim 6 , wherein when the flow valve is disposed in the second position, the second clutch is in the applied position.

8. The transmission system of claim 1 , wherein the fluid-coupling device has a Kfactor characteristic that is g function of a speed of the impeller and a torque of the impeller during operation of the fluid-coupling device, and wherein the control circuit is configured to modulate fluid pressure provided to the clutch to adjust the Kfactor characteristic.

9. The transmission system of claim 8 , wherein the control circuit is configured to slip the clutch to adjust the Kfactor characteristic.

10. The transmission system of claim 1 , further comprising a sensor coupled to the control circuit and configured to detect a rotational direction of an output of the transmission system, wherein the control circuit is configured to control the solenoid between the energized state and the de-energized state based on the rotational direction of the output detected by the sensor.

11. The transmission system of claim 10 , wherein in response to detection of a reverse rotational direction of the output by the sensor, the control circuit is configured to control the solenoid between the energized state and the de-energized state to control operation of the clutch between the applied position and the unapplied position in order to reduce rotational movement of the output.

12. A method of operating a transmission system, the transmission system including a fluid-coupling device having an input coupled to an impeller, an output coupled to a turbine, and a stator disposed between the impeller and the turbine, an electro-hydraulic control system having a flow valve disposed in fluid communication with the input and the output of the fluid-coupling device that is movable between at least a first position and a second position, at least one trim valve system fluidly coupled to the flow valve, and a solenoid disposed in fluid communication with the flow valve that is electrically controllable between an energized state and a de-energized state, a clutch disposable in fluid communication with the flow valve that is controllable between an applied position and an unapplied position, and a control circuit coupled to the at least one trim valve system and the solenoid, the method comprising:
de-energizing, by the control circuit, the solenoid to cause operation of the flow valve in the first position;
fluidly coupling, by the flow valve, the at least one trim valve system with the clutch to cause operation of the clutch in the applied position when the flow valve is in the first position;
coupling, by the clutch, the stator to ground when the clutch is in the applied position; and
reducing an output speed of an output of the transmission system when the stator is coupled to the ground.

13. The method of claim 12 , wherein coupling the stator to the ground when the clutch is in the applied position comprises locking the stator from rotating.

14. The method of claim 12 , further comprising:
energizing, by the control circuit, the solenoid to cause operation of the flow valve in the second position;
fluidly de-coupling, by the flow valve, the at least one trim valve system from the clutch to cause operation of the clutch in the unapplied position when the flow valve is in the second position; and
de-coupling, by the clutch, the stator from the ground to allow the stator to rotate when the clutch is in the unapplied position.

15. The method of claim 12 , further comprising:
modulating, by the control circuit, a fluid pressure provided to the clutch to slip the clutch and adjust a Kfactor characteristic of the fluid-coupling device.

16. The method of claim 12 , wherein the transmission system has a sensor coupled to the control circuit and configured to detect a rotational direction of the output of the transmission system, the method further comprising:
detecting, by the sensor, the rotational direction of the output of the transmission system; and
controlling, by the control circuit, the clutch between the applied position and the unapplied position to reduce rotation of the output based on the detected rotational direction of the output.

17. The method of claim 12 , wherein the transmission system has a second clutch disposable in fluid communication with the flow valve, the method further comprising:
energizing, by the control circuit, the solenoid to cause operation of the flow valve in the second position;
fluidly coupling, by the flow valve, the at least one trim system to the second clutch to cause application of the second clutch; and
coupling, by the second clutch, the impeller and the tur

Assignees

• Allison Transm Inc

Inventors

• Rietdorf Michael
• Long Charles F

Classifications

• F16D48/062

  of a clutch system with a plurality of fluid actuated clutches · CPC title

• F16D2500/1027

  Details about the hydraulic valves · CPC title

• F16D2500/10412

  Transmission line of a vehicle · CPC title

• F16D2500/1045

  Friction clutch · CPC title

• F16D2500/70484

  Output shaft speed · CPC title