Clutch for continuously variable transmission and method of operating clutch

Patent metadata

Field	Value
Publication number	US-9738286-B1
Application number	US-201615181486-A
Country	US
Kind code	B1
Filing date	Jun 14, 2016
Priority date	Jun 14, 2016
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A vehicle including a continuously variable transmission including a gear selectively locked to an output shaft via a clutch actuated by an electric coil. The vehicle also includes a controller configured to, in response to wheel hop being detected, energize the coil to disengage the clutch allowing the gear and the output shaft to rotate independently of each other.

First claim

What is claimed is:

1. A vehicle comprising:
a continuously variable transmission including a gear selectively locked to an output shaft via a clutch actuated by an electric coil; and
a controller configured to, in response to wheel hop being detected, energize the coil to disengage the clutch allowing the gear and the output shaft to rotate independently of each other.

2. The vehicle of claim 1 , wherein the clutch is biased to lock the gear relative to the shaft.

3. The vehicle of claim 1 , wherein the clutch further includes an armature actuatable by the coil to disengage the clutch in response to the coil being energized.

4. The vehicle of claim 1 , wherein the clutch further includes an outer race on the gear, an inner race fixed to the output shaft, and at least one pawl biased to lock the races and actuatable to unlock the races in response to the coil being energized.

5. The vehicle of claim 4 , wherein the clutch further includes an armature configured to, in response to the coil being energized, move the at least one pawl to a tucked position unlocking the races.

6. The vehicle of claim 1 , wherein the wheel hop is detected based on a speed of the output shaft and a speed of a driven wheel of the vehicle.

7. The vehicle of claim 1 , wherein the controller is further configured to receive a wheel-speed signal, and wherein the wheel hop is detected in response to the wheel-speed signal oscillating beyond a preset range.

8. The vehicle of claim 7 , wherein the controller is further configured to receive a shaft-speed signal indicating a speed of the output shaft, and wherein the wheel hop is detected further in response to the shaft-speed signal oscillating beyond a preset range.

9. The vehicle of claim 8 , wherein the wheel hop is detected further in response to the wheel-speed oscillating beyond the preset range before the shaft-speed signal oscillating beyond the preset range.

10. A vehicle comprising:
a continuously variable transmission including a clutch having:
an inner race fixed to an output shaft,
an outer race fixed to a gear,
pawls biased to a deployed position in which the pawls lock the races placing the gear and shaft in a fixed relationship, and movable to a tucked position in which the races are unlocked, and
an armature configured to move the pawls; and

a controller configured to, in response to wheel hop being detected, actuate the armature to move the pawls to the tucked position to unlock the races allowing the gear and shaft to rotate independently of each other.

11. The vehicle of claim 10 , wherein the outer race is integrally formed with the gear.

12. The vehicle of claim 10 , wherein the armature further includes pins arranged to engage the pawls to move the pawls to the tucked position.

13. The vehicle of claim 10 , wherein the armature is slidably connected to the outer race.

14. The vehicle of claim 10 , wherein the clutch further comprises an electric coil, and wherein the armature is actuated by a magnetic field of the coil in response to the coil be energized by the controller during wheel hop.

15. The vehicle of claim 10 , wherein the wheel hop is detected based on a speed of the output shaft and a speed of a driven wheel of the vehicle.

16. The vehicle of claim 10 , wherein the controller is further configured to, in response to the actuation of the armature, reduce torque of an engine of the vehicle.

17. A method of controlling an output-shaft clutch of a continuously variable transmission, the method comprising:
in response to wheel hop being detected, energizing an electric coil to unlock the clutch allowing an output shaft that extends through the clutch to rotate independently of a gear fixed to the clutch; and
in response to wheel hop ending, de-energizing the coil to lock the clutch and fix the gear to the output shaft.

18. The method of claim 17 further comprising reducing torque of an engine driveably connected to the transmission.

19. The method of claim 17 further comprising:
receiving a wheel-speed signal; and
in response to the wheel-speed signal oscillating beyond a preset range, energizing the electric coil.

20. The method of claim 19 further comprising:
receiving a shaft-speed signal indicating a speed of the output shaft; and
in response to the shaft-speed signal oscillating beyond a preset range after the wheel-speed signal oscillating beyond the preset range, energizing the electric coil.

Assignees

• Ford Global Tech Llc

Inventors

• Trent James
• Bird Norman Jerry
• Trent Matthew Thomas

Classifications

• F16D2500/3028

  Voltage · CPC title

• F16D2500/1022

  Electromagnet · CPC title

• F16D2500/3115

  Vehicle wheel speed · CPC title

• F16D2500/30426

  Speed of the output shaft · CPC title

• B60W2710/021

  Clutch engagement state · CPC title