Variable travel stop to increase worm gear durability

Patent metadata

Field	Value
Publication number	US-11697454-B2
Application number	US-202117203973-A
Country	US
Kind code	B2
Filing date	Mar 17, 2021
Priority date	Mar 27, 2020
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

Technical solutions are described for controlling operation of a motor using a controller to: energize the motor to rotate driveshaft and a worm; drive a worm gear by the worm; stop the motor from rotating the driveshaft in response to the worm gear rotating to a given one of a plurality of first stop positions; and change the given one of the first stop positions to another one of the first stop positions. A method for controlling a machine comprises: rotating a driveshaft by a motor; driving a worm gear by a worm to cause the worm gear to rotate; stopping the motor from rotating the driveshaft in response to the worm gear rotating to a given one of a plurality of first stop positions; and changing the given one of the first stop positions to another one of the first stop positions.

First claim

What is claimed is:

1. A control system for controlling operation of a motor, comprising:
a processor; and
memory that includes instructions that, when executed by the processor, cause the processor to:
energize the motor to rotate a driveshaft coupled to a worm and to thereby drive a worm gear to rotate in a first direction;
stop the motor from rotating the driveshaft in response to the worm gear rotating in the first direction to or beyond a given one of a plurality of first stop positions each having distinct locations spaced apart from one another;
energize the motor to drive the worm gear to rotate in a second direction opposite the first direction and away from the plurality of first stop positions; and
change the given one of the plurality of first stop positions to another one of the plurality of first stop positions to cause the motor to stop rotating the driveshaft in the first direction at or beyond the another one of the plurality of stop positions during a subsequent cycle,
wherein changing the given one of the plurality of first stop positions to another one of the plurality of first stop positions comprises at least one of: changing the given one of the plurality of first stop positions in a predetermined pattern, or changing the given one of the plurality of first stop positions each time the worm gear is driven away from the given one of the plurality of first stop positions.

2. The control system of claim 1 , wherein the instructions, when executed by the processor, further cause the processor to:
stop the motor from rotating the driveshaft in response to the worm gear rotating in the second direction to or beyond a given one of a plurality of second stop positions; and
change the given one of the plurality of second stop positions to another one of the plurality of second stop positions.

3. The control system of claim 1 , wherein the plurality of first stop positions each correspond to different gear teeth on the worm gear.

4. The control system of claim 1 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by one or more gear teeth of the worm gear.

5. The control system of claim 1 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by two or more gear teeth of the worm gear.

6. The control system of claim 1 , wherein the plurality of first stop positions includes three different first stop positions.

7. The control system of claim 1 , wherein the motor is configured to perform at least one of: applying an assist torque to a steering system of a vehicle, and controlling the steering system.

8. A method for controlling a machine, the method comprising:
rotating, by a motor, a driveshaft coupled to a worm to thereby drive a worm gear to rotate in a first direction;
stopping the motor from rotating the driveshaft in response to the worm gear rotating in the first direction to or beyond a given one of a plurality of first stop positions each having distinct locations spaced apart from one another;
energizing the motor to drive the worm gear to rotate in a second direction opposite the first direction and away from the plurality of first stop positions; and
changing the given one of the plurality of first stop positions to another one of the plurality of first stop positions to cause the motor to stop rotating the driveshaft in the first direction at or beyond the another one of the plurality of stop positions during a subsequent cycle,
wherein changing the given one of the plurality of first stop positions to another one of the plurality of first stop positions is performed each time the worm gear is driven away from the given one of the plurality of first stop positions.

9. The method of claim 8 , further comprising:
stopping the motor from rotating the driveshaft in response to the worm gear rotating in the second direction to or beyond a given one of a plurality of second stop positions; and
changing the given one of the plurality of second stop positions to another one of the plurality of second stop positions.

10. The method of claim 8 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by one gear tooth of the worm gear.

11. The method of claim 8 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by an amount between one and two gear teeth of the worm gear.

12. The method of claim 8 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by two or more gear teeth of the worm gear.

13. The method of claim 8 , wherein the plurality of first stop positions includes three different first stop positions.

14. The method of claim 8 , wherein the machine is configured to perform at least one of: applying an assist torque to a steering system of a vehicle, and controlling the steering system.

15. A method for controlling a machine, the method comprising:
rotating, by a motor, a driveshaft coupled to a worm to thereby drive a worm gear to rotate in a first direction;
stopping the motor from rotating the driveshaft in response to the worm gear rotating in the first direction to or beyond a given one of a plurality of first stop positions each having distinct locations spaced apart from one another;
energizing the motor to drive the worm gear to rotate in a second direction opposite the first direction and away from the plurality of first stop positions; and
changing the given one of the plurality of first stop positions to another one of the plurality of first stop positions to cause the motor to stop rotating the driveshaft in the first direction at or beyond the another one of the plurality of stop positions during a subsequent cycle,
wherein changing the given one of the plurality of first stop positions to another one of the plurality of first stop positions comprises changing the given one of the plurality of first stop positions in a predetermined pattern.

16. The method of claim 15 further comprising:
stopping the motor from rotating the driveshaft in response to the worm gear rotating in the second direction to or beyond a given one of a plurality of second stop positions; and
changing the given one of the plurality of second stop positions to another one of the plurality of second stop positions.

17. The method of claim 15 , wherein the machine is configured to perform at least one of: applying an assist torque to a steering system of a vehicle, and controlling the steering system.

18. The method of claim 15 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by one gear tooth of the worm gear.

19. The method of claim 15 , wherein adjacent ones of the plurality of first stop positions are spaced apart from one another by an amount between one and two gear teeth of the worm gear.

20. The method of claim 15 , wherein the plurality of first stop positions includes three different first stop positions.

Assignees

• Steering Solutions Ip Holding

Inventors

• Nakielski Marcin J
• Franiasz Jakub
• Chodur Kamil

Classifications

• F16H1/16

  comprising worm and worm-wheel · CPC title

• H02K7/1166

  comprising worm and worm-wheel (structural association with bearings specially adapted for worm gear drives H02K7/081) · CPC title

• H02P23/24

  Controlling the direction, e.g. clockwise or counterclockwise · CPC title

• B62D5/0469 Primary

  End-of-stroke control · CPC title

• H02P23/183

  of one shaft without controlling the prime mover · CPC title