Transmission lock for electric vehicle

Patent metadata

Field	Value
Publication number	US-11841081-B2
Application number	US-202117398752-A
Country	US
Kind code	B2
Filing date	Aug 10, 2021
Priority date	Aug 10, 2020
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

A park lock for an output drive gear includes a pawl, a rotational cam, and a rotational spring. The pawl has an engagement protrusion that extends outward from a body disposed on a pawl rotational shaft, such that rotation moves the engagement protrusion toward the output drive gear. The rotational cam rotates such that a circumferential side engages with a portion of the pawl opposite the engagement protrusion, causing rotation of the pawl about the rotational pawl shaft to move the engagement protrusion towards the output drive gear. The rotational spring maintains tension on the pawl and cam such that the engagement protrusion maintains an engagement with the output drive gear based on rotation of the cam and a speed of the output drive gear.

First claim

What is claimed is:

1. A park lock, comprising:
an output drive gear disposed on an output drive shaft and having engagement projections extending outwardly from a circular body and wherein the engagement projections form an engagement space between adjacent pairs of the engagement projections;
a pawl having a body with an engagement protrusion extending outward from the body, the body disposed on a pawl rotational shaft at a first end of the body such that rotation of the pawl about the pawl rotational shaft rotates the engagement protrusion in a direction of the output drive gear;
a rotational cam disposed on a cam shaft that is rotated such that a circumferential cam side face engages with a portion of the pawl opposite the engagement protrusion to cause the rotation of the pawl about the pawl rotational shaft to thereby move the engagement protrusion towards the output drive gear into one of the engagement spaces between the engagement projections;
at least one rotational spring connected to maintain tension on the pawl and cam such that the engagement protrusion maintains an engagement with the engagement spaces and engagement projections that is based on rotation of the cam and a speed of the output drive gear, wherein the engagement protrusion engages the engagement spaces and engagement projections in a ratcheting motion when the speed of the output drive gear is above a threshold and fully engages the engagement spaces and engagement projections when the speed of the output drive gear is at or below the threshold; and
a stopping flange disposed on an actuator shaft and configured to limit movement of the pawl, wherein the stopping flange comprises a stopping pin extending from the stopping flange in a direction parallel with the actuator shaft and configured to be stopped by a fixed stopping plate.

2. The park lock according to claim 1 , wherein the circumferential cam side face of the rotational cam has a region of increasing radius.

3. The park lock according to claim 2 , wherein the circumferential cam side face of the rotational cam has a stepped change in radius.

4. The park lock according to claim 1 , wherein the at least one rotational spring comprises one of a torsion spring or nested torsion springs.

5. The park lock according to claim 1 , wherein the at least one spring comprises a first torsion spring wrapped around the pawl rotational shaft.

6. The park lock according to claim 1 , wherein the at least one rotational spring comprises a first torsion spring wrapped around the pawl rotational shaft and a second torsion spring wrapped around the cam shaft.

7. The park lock according to claim 1 , further comprising:
nested coaxial springs wrapped around the actuator shaft.

8. The park lock according to claim 1 , wherein the pawl and the rotational cam are mounted inside a removable portion of a casing for a drive assembly.

9. A park lock, comprising:
an output drive gear disposed on an output drive shaft and having engagement projections extending outwardly from a circular body and wherein the engagement projections form an engagement space between adjacent pairs of the engagement projections;
a pawl having a body with an engagement protrusion extending outward from the body, the body disposed on a pawl rotational shaft such that rotation of the pawl about the pawl rotational shaft rotates the engagement protrusion in a direction of the output drive gear;
a rotational cam disposed on a cam shaft that is rotated such that a circumferential cam side face engages with a portion of the pawl opposite the engagement protrusion to cause the rotation of the pawl about the pawl rotational shaft to thereby move the engagement protrusion towards the output drive gear into one of the engagement spaces between the engagement projections;
at least one rotational spring connected to maintain tension on the pawl and cam such that the engagement protrusion maintains an engagement with the engagement spaces and engagement projections that is based on rotation of the cam and a speed of the output drive gear, wherein the engagement protrusion is configured to engage the engagement spaces and engagement projections in a ratcheting motion when the speed of the output drive gear is above a threshold corresponding to the tension on the pawl and cam and to fully engage the engagement spaces and engagement projections when the speed of the output drive gear is at or below the threshold; and
a stopping flange on an actuator shaft, the stopping flange including a bent portion extending in a direction parallel with the actuator shaft and configured to limit movement of the pawl.

10. The park lock according to claim 9 , wherein the bent portion is configured to contact a surface of the rotational cam.

11. A method of locking an automatic transmission, the method comprising:
disposing an output drive gear on an output drive shaft and having engagement projections extending outwardly from a circular body and wherein the engagement projections form an engagement space between adjacent pairs of the engagement projections;
providing a pawl having a body with an engagement protrusion extending outward from the body, the body disposed on a pawl rotational shaft at a first end of the body such that rotation of the pawl about the pawl rotational shaft rotates the engagement protrusion in a direction of the output drive gear;
disposing a rotational cam on a cam shaft that is rotated such that a circumferential cam side face engages with a portion of the pawl opposite the engagement protrusion to cause the rotation of the pawl about the pawl rotational shaft to thereby move the engagement protrusion towards the output drive gear into one of the engagement spaces between the engagement projections; and
connecting at least one rotational spring to maintain tension on the pawl and cam such that the engagement protrusion maintains an engagement with the engagement spaces and engagement projections that is based on rotation of the cam and a speed of the output drive gear, wherein the engagement protrusion engages the engagement spaces and engagement projections in a ratcheting motion when the speed of the output drive gear is above a threshold and fully engages the engagement spaces and engagement projections when the speed of the output drive gear is at or below the threshold.

12. The method according to claim 11 , wherein the circumferential cam side face of the rotational cam has a region of increasing radius.

13. The method according to claim 12 , wherein the circumferential cam side face of the rotational cam has a stepped change in radius.

14. The method according to claim 11 , wherein the at least one rotational spring comprises one of a torsion spring or nested torsion springs.

15. The method according to claim 11 , wherein the at least one rotational spring comprises a first torsion spring wrapped around the pawl rotational shaft.

16. The method according to claim 11 , wherein the at least one rotational spring comprises a first torsion spring wrapped around the pawl rotational shaft and a second torsion spring wrapped around a rotation shaft for the cam.

17. The method according to claim 11 , further comprising:
providing a stopping flange configured to limit movement of the pawl.

18. The method according to claim 17 , wherein the stopping flange comprises a stopping pin configured to be stopped by stopping pegs on a fixed stopping plate.

19. The method according to claim 17 , wherein the stopping flange comprises a bent portion configured to contac

Assignees

• Canoo Tech Inc

Inventors

• Diebel Jackson George
• Mason John
• Garmel Charles
• Weicker Phillip John

Classifications

• F16H63/3425 Primary

  characterised by pawls or wheels · CPC title

• F16H53/00

  Cams or cam-followers, e.g. rollers for gearing mechanisms · CPC title