BALLSCREW ASSEMBLY WITH DETECTION FEATURE

• US 20100162837A1
• Filed: 12/30/2008
• Published: 07/01/2010
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Maines, Garen R., Cavalier, Donald R.
• Granted Patent: US 8,281,678 B2
• Time in Patent Office: Days
• US Class Current: 74/89.230
• CPC Class Codes: F16H 2025/2081 Parallel arrangement of drive motor to screw axis
• CPC Class Codes: F16H 25/22 with balls, rollers, or similar members between the co-operating parts; Elements essential to the use of such members
• CPC Class Codes: Y10T 74/18576 including screw and nut
• CPC Class Codes: Y10T 74/18704 Means to selectively lock or retard screw or nut
• CPC Class Codes: Y10T 74/19637 with brake means for gearing
• CPC Class Codes: Y10T 74/19744 Rolling element engaging thread
• CPC Class Codes: Y10T 74/19847 torque actuated safety devices

Abstract

A ballscrew assembly for an actuator is provided. In an embodiment, the ballscrew assembly includes a ball nut assembly including a view port; a ballscrew provided within at least a portion of the ball nut assembly; an inner rod provided within the ballscrew in the direction of the longitudinal axis, the inner rod including an enlarged end portion; and a compression mechanism, such that at least a portion of the compression mechanism is provided between the enlarged end portion and the ballscrew. In another embodiment the assembly is configured such that when the inner rod is in a failed state, the compression mechanism provides a force that moves the visual indicator toward the view port. In another embodiment, the assembly includes a proximity sensor in addition to, or in lieu, of a view port to detect a failure.

Claims

1. A ballscrew assembly for an actuator, the ballscrew assembly comprising:

a ball nut assembly including a view port;

a ballscrew provided within at least a portion of the ball nut assembly, the ballscrew having a longitudinal axis;

an inner rod provided within the ballscrew in the direction of the longitudinal axis, the inner rod including an enlarged end portion; and

a compression mechanism, at least a portion of the compression mechanism provided between the enlarged end portion and the ballscrew;

wherein, when the inner rod is in a failed state, the compression mechanism provides a force that moves the visual indicator toward the view port.

2. The assembly of claim 1, wherein the enlarged end portion comprises a ball nut.

3. The assembly of claim 1, wherein the compression mechanism comprises a spring.

4. The assembly of claim 1, wherein a portion of the compression mechanism is provided around the inner rod.

5. The assembly of claim 1, wherein the enlarged end portion includes a visual indicator.

6. The assembly of claim 5, wherein the visual indicator includes a red plug.

7. The assembly of claim 5, wherein the visual indicator includes an extended portion.

8. The assembly of claim 1, wherein the view port comprises an aperture or opening.

9. The assembly of claim 8, wherein the visual indicator comprises an extended portion and, in a failed state, a portion of the extended portion of the visual indicator extends to or through the aperture or opening.

10. The assembly of claim 1, including a no-back assembly connected to the ball nut assembly.

11. The assembly of claim 10, wherein the no-back assembly includes a roller clutch, rollers, and bearings.

12. A ballscrew assembly for an actuator, the ballscrew assembly comprising:

a ball nut assembly, including a ballscrew provided within at least a portion of the ball nut assembly, the ballscrew having a longitudinal axis;

an inner rod provided within the ballscrew and extending in the direction of the longitudinal axis;

a proximity sensor positioned behind the ballscrew;

wherein, in the event of inner rod separation, a spring force forces an aft portion of the failed rod rearward toward the proximity sensor.

13. The assembly of claim 12, wherein the proximity sensor comprises an inductive proximity sensor.

14. The assembly of claim 12, wherein the assembly includes an inner torque tube.

15. The assembly of claim 14, including an outer torque tube, wherein, in the event of inner torque tube separation, the outer torque tube is configured to prevent rotation of the ballscrew.

16. The assembly of claim 12, the assembly including a clutch, rollers, and bearings.

17. The assembly of claim 12, the assembly including a differential gear assembly.

18. The assembly of claim 17, including two motors, wherein the differential gear assembly is configured to transmit an average torque.

19. The assembly of claim 12, including a DC motor.

20. The assembly of claim 19, wherein the DC motor is a brushless motor with an integral electromechanical brake.