ACTUATOR BALL SCREW FOR IMPROVED LOAD SHARING

• US 20170241526A1
• Filed: 02/19/2016
• Published: 08/24/2017
• Est. Priority Date: 02/19/2016
• Status: Active Grant

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Drennen, David, Klode, Harald, Rehfus, Kevin, Mann, Satinder, Georgin, Marc, French, Robert
• Granted Patent: US 10,830,321 B2
• Time in Patent Office: Days
• CPC Class Codes: F16D 2121/20 using electromagnets
• CPC Class Codes: F16D 2121/24 using motors
• CPC Class Codes: F16D 2125/40 Screw-and-nut
• CPC Class Codes: F16D 65/18 adapted for drawing members together , e.g. for disc brakes
• CPC Class Codes: F16H 2025/2087 using planetary gears
• CPC Class Codes: F16H 2025/2445 Supports or other means for compensating misalignment or offset between screw and nut
• CPC Class Codes: F16H 25/2204 with balls
• CPC Class Codes: F16H 25/2228 the device for circulation forming a part of the screw member
• CPC Class Codes: F16H 25/24 Elements essential to such mechanisms, e.g. screws, nuts F16H25/22 takes precedence

Abstract

The present disclosure provides an actuator assembly having a ball nut comprising a helical track and a ball screw. The ball screw of the actuator assembly includes a first translation bearing track having a first diameter, wherein the helical track and the first translation bearing track form a first translation bearing raceway in which a first translation bearing ball is disposed. The ball screw further includes a second translation bearing track having a second diameter, wherein the helical track and the second translation bearing track form a second translation bearing raceway in which a second translation bearing ball is disposed. The first diameter and the second diameter are not equal.

Claims

1. An actuator assembly comprising:

a ball nut comprising a helical track; and

a ball screw comprising;

a first translation bearing track having a first diameter, wherein the helical track and the first translation bearing track form a first translation bearing raceway in which a first translation bearing ball is disposed; and

a second translation bearing track having a second diameter, wherein the helical track and the second translation bearing track form a second translation bearing raceway in which a second translation bearing ball is disposed;

wherein the first diameter and the second diameter are not equal.

2. The actuator assembly of claim 1, wherein at least one of the first translation bearing track or the second translation bearing track comprises a cross-under track having a cross-under portion.

3. The actuator assembly of claim 1, wherein the ball screw further comprises:

a third translation bearing track having a third diameter, wherein the helical track and the third translation bearing track form a third translation bearing raceway in which a third translation bearing ball is disposed.

4. The actuator assembly of claim 3, wherein the first diameter is larger than at least one of the second diameter or the third diameter.

5. The actuator assembly of claim 4, wherein the first translation bearing track is proximal to the second translation bearing track and the third translation bearing track.

6. The actuator assembly of claim 4, wherein the first translation bearing track is distal to the second translation bearing track and the third translation bearing track.

7. The actuator assembly of claim 4, wherein the first translation bearing track is medial to the second translation bearing track and the third translation bearing track.

8. The actuator assembly of claim 4, wherein the first translation bearing raceway comprises a proximal-most translation bearing raceway disposed in the actuator assembly.

9. An actuator assembly comprising:

an actuator drive unit (ADU) housing comprising a first ADU track and a second ADU track; and

a ball screw comprising;

a first thrust bearing track having a fourth diameter, wherein the first ADU track and the first thrust bearing track form a first thrust bearing raceway in which a first thrust bearing ball is disposed; and

a second thrust bearing track having a fifth diameter, wherein the second ADU track and the second thrust bearing track form a second thrust bearing raceway in which a second thrust bearing ball is disposed;

wherein the fourth diameter and the fifth diameter are not equal.

10. The actuator assembly of claim 9, wherein the ADU housing includes a third ADU track;

and

wherein the ball screw includes a third thrust bearing track having a sixth diameter, wherein the third ADU track and the third thrust bearing track form a third thrust bearing raceway in which a third thrust bearing ball is disposed.

11. The actuator assembly of claim 10, wherein the fourth diameter is larger than at least one of the fifth diameter or the sixth diameter.

12. The actuator assembly of claim 11, wherein the first thrust bearing track is proximal to the second thrust bearing track and the third thrust bearing track.

13. The actuator assembly of claim 11, wherein the first thrust bearing track is distal to the second thrust bearing track and the third thrust bearing track.

14. The actuator assembly of claim 11, wherein the first thrust bearing track is medial to the second thrust bearing track and the third thrust bearing track.

15. The actuator assembly of claim 10, wherein the first thrust bearing raceway comprises a distal-most thrust bearing raceway disposed in the actuator assembly.

16. A brake actuator comprising an actuator assembly having a variable bearing raceway size configuration.

17. The brake actuator of claim 16, wherein the actuator assembly comprises:

a ball nut including a helical track; and

a ball screw including;

a first translation bearing track, wherein the helical track and the first translation bearing track form a first translation bearing raceway having a first diameter in which a first translation bearing ball is disposed; and

a second translation bearing track, wherein the helical track and the second translation bearing track form a second translation bearing raceway having a second diameter in which a second translation bearing ball is disposed;

wherein the first diameter and the second diameter are not equal.

18. The brake actuator of claim 17, wherein the ball screw further comprises:

a third translation bearing track, wherein the helical track and the third translation bearing track form a third translation bearing raceway having a third diameter in which a third translation bearing ball is disposed; and

wherein the first diameter is larger than at least one of the second diameter or the third diameter.

19. The brake actuator of claim 16, wherein the actuator assembly comprises:

an actuator drive unit (ADU) housing including a first ADU track and a second ADU track; and

a ball screw including;

a first thrust bearing track, wherein the first ADU track and the first thrust bearing track form a first thrust bearing raceway having a fourth diameter in which a first thrust bearing ball is disposed; and

a second thrust bearing track, wherein the second ADU track and the second thrust bearing track form a second thrust bearing raceway having a fifth diameter in which a second thrust bearing ball is disposed;

wherein the first diameter and the second diameter are not equal.

20. The brake actuator of claim 19, wherein the ADU housing includes a third ADU track;

and

wherein the ball screw includes a third thrust bearing track;

wherein the third ADU track and the third thrust bearing track form a third thrust bearing raceway having a sixth diameter in which a third thrust bearing ball is disposed; and

wherein the fourth diameter is larger than at least one of the fifth diameter or the sixth diameter.